Study on Genetic Diversity of Turf Bamboo Based on ISSR Marker
克隆的缺点 英语作文
Cloning,a scientific process that has been the subject of much debate,presents a myriad of potential drawbacks that are often overlooked in the face of its potential benefits.Here are some of the key disadvantages associated with cloning:1.Ethical Concerns:Cloning raises significant ethical issues.The process essentially involves creating a genetic copy of an individual,which can be seen as a violation of the sanctity of life and the uniqueness of each human being.2.Genetic Diversity:One of the fundamental principles of natural selection is the importance of genetic diversity for the survival and adaptation of species.Cloning could lead to a reduction in genetic diversity,making populations more susceptible to diseases and less adaptable to environmental changes.3.Health Risks:Cloned animals have shown a higher incidence of health problems and abnormalities.This could be due to the cloning process itself,which may introduce errors or mutations in the genetic material.If applied to humans,these health risks could be significant and potentially lifethreatening.4.Psychological Impact:The psychological effects of being a clone are not well understood,but it is likely that clones would face unique challenges in terms of identity and selfperception.They may struggle with the knowledge that they are not unique and could experience a sense of depersonalization or loss of individuality.5.Social Implications:Society may struggle to integrate clones,leading to potential discrimination or social ostracism.The concept of family and lineage could be fundamentally altered,with implications for inheritance,social roles,and interpersonal relationships.6.Economic and Legal Issues:The commercialization of cloning could lead to a market for human clones,with serious implications for human rights and dignity.There are also concerns about the legal status of clones,including their rights and responsibilities.7.Potential for Abuse:Cloning technology could be misused for nefarious purposes,such as creating a workforce of clones or for military applications.This could lead to a devaluation of human life and an increase in exploitation.8.Environmental Impact:The mass production of clones could have unforeseen environmental consequences,particularly if clones are used for agricultural or industrial purposes.The ecological balance could be disrupted,leading to unforeseen consequences for other species and ecosystems.9.Moral and Religious Objections:Many religious and philosophical traditions oppose cloning on moral grounds,arguing that it is an affront to the natural order and to the divine.This opposition can create societal divisions and conflicts.10.Unpredictability:The longterm effects of cloning are not fully known,and there is a risk that unforeseen consequences could arise as clones age and interact with the world in ways that are different from naturally conceived individuals.In conclusion,while cloning may offer some potential benefits,such as the ability to reproduce endangered species or to provide organs for transplantation,the risks and drawbacks are significant and must be carefully considered.The potential for harm to individuals,societies,and the environment must be weighed against the potential benefits, and a cautious approach is warranted.。
Analysis of Genetic Diversity and Population Structure
Agricultural Sciences in China2010, 9(9): 1251-1262September 2010Received 30 October, 2009 Accepted 16 April, 2010Analysis of Genetic Diversity and Population Structure of Maize Landraces from the South Maize Region of ChinaLIU Zhi-zhai 1, 2, GUO Rong-hua 2, 3, ZHAO Jiu-ran 4, CAI Yi-lin 1, W ANG Feng-ge 4, CAO Mo-ju 3, W ANG Rong-huan 2, 4, SHI Yun-su 2, SONG Yan-chun 2, WANG Tian-yu 2 and LI Y u 21Maize Research Institute, Southwest University, Chongqing 400716, P.R.China2Institue of Crop Sciences/National Key Facility for Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences,Beijing 100081, P.R.China3Maize Research Institute, Sichuan Agricultural University, Ya’an 625014, P.R.China4Maize Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100089, P.R.ChinaAbstractUnderstanding genetic diversity and population structure of landraces is important in utilization of these germplasm in breeding programs. In the present study, a total of 143 core maize landraces from the South Maize Region (SR) of China,which can represent the general profile of the genetic diversity in the landraces germplasm of SR, were genotyped by 54DNA microsatellite markers. Totally, 517 alleles (ranging from 4 to 22) were detected among these landraces, with an average of 9.57 alleles per locus. The total gene diversity of these core landraces was 0.61, suggesting a rather higher level of genetic diversity. Analysis of population structure based on Bayesian method obtained the samilar result as the phylogeny neighbor-joining (NJ) method. The results indicated that the whole set of 143 core landraces could be clustered into two distinct groups. All landraces from Guangdong, Hainan, and 15 landraces from Jiangxi were clustered into group 1, while those from the other regions of SR formed the group 2. The results from the analysis of genetic diversity showed that both of groups possessed a similar gene diversity, but group 1 possessed relatively lower mean alleles per locus (6.63) and distinct alleles (91) than group 2 (7.94 and 110, respectively). The relatively high richness of total alleles and distinct alleles preserved in the core landraces from SR suggested that all these germplasm could be useful resources in germplasm enhancement and maize breeding in China.Key words :maize, core landraces, genetic diversity, population structureINTRODUCTIONMaize has been grown in China for nearly 500 years since its first introduction into this second biggest pro-duction country in the world. Currently, there are six different maize growing regions throughout the coun-try according to the ecological conditions and farming systems, including three major production regions,i.e., the North Spring Maize Region, the Huang-Huai-Hai Summer Maize Region, and the Southwest MaizeRegion, and three minor regions, i.e., the South Maize Region, the Northwest Maize Region, and the Qingzang Plateau Maize Region. The South Maize Region (SR)is specific because of its importance in origin of Chi-nese maize. It is hypothesized that Chinese maize is introduced mainly from two routes. One is called the land way in which maize was first brought to Tibet from India, then to Sichuan Province in southwestern China. The other way is that maize dispersed via the oceans, first shipped to the coastal areas of southeast China by boats, and then spread all round the country1252LIU Zhi-zhai et al.(Xu 2001; Zhou 2000). SR contains all of the coastal provinces and regions lie in southeastern China.In the long-term cultivation history of maize in south-ern China, numerous landraces have been formed, in which a great amount of genetic variation was observed (Li 1998). Similar to the hybrid swapping in Europe (Reif et al. 2005a), the maize landraces have been al-most replaced by hybrids since the 1950s in China (Li 1998). However, some landraces with good adapta-tions and yield performances are still grown in a few mountainous areas of this region (Liu et al.1999). Through a great effort of collection since the 1950s, 13521 accessions of maize landraces have been cur-rently preserved in China National Genebank (CNG), and a core collection of these landraces was established (Li et al. 2004). In this core collection, a total of 143 maize landrace accessions were collected from the South Maize Region (SR) (Table 1).Since simple sequence repeat ( SSR ) markers were firstly used in human genetics (Litt and Luty 1989), it now has become one of the most widely used markers in the related researches in crops (Melchinger et al. 1998; Enoki et al. 2005), especially in the molecular characterization of genetic resources, e.g., soybean [Glycine max (L.) Merr] (Xie et al. 2005), rice (Orya sativa L.) (Garris et al. 2005), and wheat (Triticum aestivum) (Chao et al. 2007). In maize (Zea mays L.), numerous studies focusing on the genetic diversity and population structure of landraces and inbred lines in many countries and regions worldwide have been pub-lished (Liu et al. 2003; Vegouroux et al. 2005; Reif et al. 2006; Wang et al. 2008). These activities of documenting genetic diversity and population structure of maize genetic resources have facilitated the under-standing of genetic bases of maize landraces, the utili-zation of these resources, and the mining of favorable alleles from landraces. Although some studies on ge-netic diversity of Chinese maize inbred lines were con-ducted (Yu et al. 2007; Wang et al. 2008), the general profile of genetic diversity in Chinese maize landraces is scarce. Especially, there are not any reports on ge-netic diversity of the maize landraces collected from SR, a possibly earliest maize growing area in China. In this paper, a total of 143 landraces from SR listed in the core collection of CNG were genotyped by using SSR markers, with the aim of revealing genetic diver-sity of the landraces from SR (Table 2) of China and examining genetic relationships and population struc-ture of these landraces.MATERIALS AND METHODSPlant materials and DNA extractionTotally, 143 landraces from SR which are listed in the core collection of CNG established by sequential strati-fication method (Liu et al. 2004) were used in the present study. Detailed information of all these landrace accessions is listed in Table 1. For each landrace, DNA sample was extracted by a CTAB method (Saghi-Maroof et al. 1984) from a bulk pool constructed by an equal-amount of leaves materials sampled from 15 random-chosen plants of each landrace according to the proce-dure of Reif et al. (2005b).SSR genotypingA total of 54 simple sequence repeat (SSR) markers covering the entire maize genome were screened to fin-gerprint all of the 143 core landrace accessions (Table 3). 5´ end of the left primer of each locus was tailed by an M13 sequence of 5´-CACGACGTTGTAAAACGAC-3´. PCR amplification was performed in a 15 L reac-tion containing 80 ng of template DNA, 7.5 mmol L-1 of each of the four dNTPs, 1×Taq polymerase buffer, 1.5 mmol L-1 MgCl2, 1 U Taq polymerase (Tiangen Biotech Co. Ltd., Beijing, China), 1.2 mol L-1 of forward primer and universal fluorescent labeled M13 primer, and 0.3 mol L-1 of M13 sequence tailed reverse primer (Schuelke 2000). The amplification was carried out in a 96-well DNA thermal cycler (GeneAmp PCR System 9700, Applied Biosystem, USA). PCR products were size-separated on an ABI Prism 3730XL DNA sequencer (HitachiHigh-Technologies Corporation, Tokyo, Japan) via the software packages of GENEMAPPER and GeneMarker ver. 6 (SoftGenetics, USA).Data analysesAverage number of alleles per locus and average num-ber of group-specific alleles per locus were identifiedAnalysis of Genetic Diversity and Population Structure of Maize Landraces from the South Maize Region of China 1253Table 1 The detailed information about the landraces used in the present studyPGS revealed by Structure1) NJ dendragram revealed Group 1 Group 2 by phylogenetic analysis140-150tian 00120005AnH-06Jingde Anhui 0.0060.994Group 2170tian00120006AnH-07Jingde Anhui 0.0050.995Group 2Zixihuangyumi00120007AnH-08Zixi Anhui 0.0020.998Group 2Zixibaihuangzayumi 00120008AnH-09Zixi Anhui 0.0030.997Group 2Baiyulu 00120020AnH-10Yuexi Anhui 0.0060.994Group 2Wuhuazi 00120021AnH-11Yuexi Anhui 0.0030.997Group 2Tongbai 00120035AnH-12Tongling Anhui 0.0060.994Group 2Yangyulu 00120036AnH-13Yuexi Anhui 0.0040.996Group 2Huangli 00120037AnH-14Tunxi Anhui 0.0410.959Group 2Baiyumi 00120038AnH-15Tunxi Anhui 0.0030.997Group 2Dapigu00120039AnH-16Tunxi Anhui 0.0350.965Group 2150tianbaiyumi 00120040AnH-17Xiuning Anhui 0.0020.998Group 2Xiuning60tian 00120042AnH-18Xiuning Anhui 0.0040.996Group 2Wubaogu 00120044AnH-19ShitaiAnhui 0.0020.998Group 2Kuyumi00130001FuJ-01Shanghang Fujian 0.0050.995Group 2Zhongdouyumi 00130003FuJ-02Shanghang Fujian 0.0380.962Group 2Baixinyumi 00130004FuJ-03Liancheng Fujian 0.0040.996Group 2Hongxinyumi 00130005FuJ-04Liancheng Fujian 0.0340.966Group 2Baibaogu 00130008FuJ-05Changding Fujian 0.0030.997Group 2Huangyumi 00130011FuJ-06Jiangyang Fujian 0.0020.998Group 2Huabaomi 00130013FuJ-07Shaowu Fujian 0.0020.998Group 2Huangbaomi 00130014FuJ-08Songxi Fujian 0.0020.998Group 2Huangyumi 00130016FuJ-09Wuyishan Fujian 0.0460.954Group 2Huabaogu 00130019FuJ-10Jian’ou Fujian 0.0060.994Group 2Huangyumi 00130024FuJ-11Guangze Fujian 0.0010.999Group 2Huayumi 00130025FuJ-12Nanping Fujian 0.0040.996Group 2Huangyumi 00130026FuJ-13Nanping Fujian 0.0110.989Group 2Hongbaosu 00130027FuJ-14Longyan Fujian 0.0160.984Group 2Huangfansu 00130029FuJ-15Loangyan Fujian 0.0020.998Group 2Huangbaosu 00130031FuJ-16Zhangping Fujian 0.0060.994Group 2Huangfansu 00130033FuJ-17Zhangping Fujian0.0040.996Group 2Baolieyumi 00190001GuangD-01Guangzhou Guangdong 0.9890.011Group 1Nuomibao (I)00190005GuangD-02Shixing Guangdong 0.9740.026Group 1Nuomibao (II)00190006GuangD-03Shixing Guangdong 0.9790.021Group 1Zasehuabao 00190010GuangD-04Lechang Guangdong 0.9970.003Group 1Zihongmi 00190013GuangD-05Lechang Guangdong 0.9880.012Group 1Jiufengyumi 00190015GuangD-06Lechang Guangdong 0.9950.005Group 1Huangbaosu 00190029GuangD-07MeiGuangdong 0.9970.003Group 1Bailibao 00190032GuangD-08Xingning Guangdong 0.9980.002Group 1Nuobao00190038GuangD-09Xingning Guangdong 0.9980.002Group 1Jinlanghuang 00190048GuangD-10Jiangcheng Guangdong 0.9960.004Group 1Baimizhenzhusu 00190050GuangD-11Yangdong Guangdong 0.9940.006Group 1Huangmizhenzhusu 00190052GuangD-12Yangdong Guangdong 0.9930.007Group 1Baizhenzhu 00190061GuangD-13Yangdong Guangdong 0.9970.003Group 1Baiyumi 00190066GuangD-14Wuchuan Guangdong 0.9880.012Group 1Bendibai 00190067GuangD-15Suixi Guangdong 0.9980.002Group 1Shigubaisu 00190068GuangD-16Gaozhou Guangdong 0.9960.004Group 1Zhenzhusu 00190069GuangD-17Xinyi Guangdong 0.9960.004Group 1Nianyaxixinbai 00190070GuangD-18Huazhou Guangdong 0.9960.004Group 1Huangbaosu 00190074GuangD-19Xinxing Guangdong 0.9950.005Group 1Huangmisu 00190076GuangD-20Luoding Guangdong 0.940.060Group 1Huangmi’ai 00190078GuangD-21Luoding Guangdong 0.9980.002Group 1Bayuemai 00190084GuangD-22Liannan Guangdong 0.9910.009Group 1Baiyumi 00300001HaiN-01Haikou Hainan 0.9960.004Group 1Baiyumi 00300003HaiN-02Sanya Hainan 0.9970.003Group 1Hongyumi 00300004HaiN-03Sanya Hainan 0.9980.002Group 1Baiyumi00300011HaiN-04Tongshi Hainan 0.9990.001Group 1Zhenzhuyumi 00300013HaiN-05Tongshi Hainan 0.9980.002Group 1Zhenzhuyumi 00300015HaiN-06Qiongshan Hainan 0.9960.004Group 1Aiyumi 00300016HaiN-07Qiongshan Hainan 0.9960.004Group 1Huangyumi 00300021HaiN-08Qionghai Hainan 0.9970.003Group 1Y umi 00300025HaiN-09Qionghai Hainan 0.9870.013Group 1Accession name Entry code Analyzing code Origin (county/city)Province/Region1254LIU Zhi-zhai et al .Baiyumi00300032HaiN-10Tunchang Hainan 0.9960.004Group 1Huangyumi 00300051HaiN-11Baisha Hainan 0.9980.002Group 1Baihuangyumi 00300055HaiN-12BaishaHainan 0.9970.003Group 1Machihuangyumi 00300069HaiN-13Changjiang Hainan 0.9900.010Group 1Hongyumi00300073HaiN-14Dongfang Hainan 0.9980.002Group 1Xiaohonghuayumi 00300087HaiN-15Lingshui Hainan 0.9980.002Group 1Baiyumi00300095HaiN-16Qiongzhong Hainan 0.9950.005Group 1Y umi (Baimai)00300101HaiN-17Qiongzhong Hainan 0.9980.002Group 1Y umi (Xuemai)00300103HaiN-18Qiongzhong Hainan 0.9990.001Group 1Huangmaya 00100008JiangS-10Rugao Jiangsu 0.0040.996Group 2Bainian00100012JiangS-11Rugao Jiangsu 0.0080.992Group 2Bayebaiyumi 00100016JiangS-12Rudong Jiangsu 0.0040.996Group 2Chengtuohuang 00100021JiangS-13Qidong Jiangsu 0.0050.995Group 2Xuehuanuo 00100024JiangS-14Qidong Jiangsu 0.0020.998Group 2Laobaiyumi 00100032JiangS-15Qidong Jiangsu 0.0050.995Group 2Laobaiyumi 00100033JiangS-16Qidong Jiangsu 0.0010.999Group 2Huangwuye’er 00100035JiangS-17Hai’an Jiangsu 0.0030.997Group 2Xiangchuanhuang 00100047JiangS-18Nantong Jiangsu 0.0060.994Group 2Huangyingzi 00100094JiangS-19Xinghua Jiangsu 0.0040.996Group 2Xiaojinhuang 00100096JiangS-20Yangzhou Jiangsu 0.0010.999Group 2Liushizi00100106JiangS-21Dongtai Jiangsu 0.0030.997Group 2Kangnandabaizi 00100108JiangS-22Dongtai Jiangsu 0.0020.998Group 2Shanyumi 00140020JiangX-01Dexing Jiangxi 0.9970.003Group 1Y umi00140024JiangX-02Dexing Jiangxi 0.9970.003Group 1Tianhongyumi 00140027JiangX-03Yushan Jiangxi 0.9910.009Group 1Hongganshanyumi 00140028JiangX-04Yushan Jiangxi 0.9980.002Group 1Zaoshuyumi 00140032JiangX-05Qianshan Jiangxi 0.9970.003Group 1Y umi 00140034JiangX-06Wannian Jiangxi 0.9970.003Group 1Y umi 00140038JiangX-07De’an Jiangxi 0.9940.006Group 1Y umi00140045JiangX-08Wuning Jiangxi 0.9740.026Group 1Chihongyumi 00140049JiangX-09Wanzai Jiangxi 0.9920.008Group 1Y umi 00140052JiangX-10Wanzai Jiangxi 0.9930.007Group 1Huayumi 00140060JiangX-11Jing’an Jiangxi 0.9970.003Group 1Baiyumi 00140065JiangX-12Pingxiang Jiangxi 0.9940.006Group 1Huangyumi00140066JiangX-13Pingxiang Jiangxi 0.9680.032Group 1Nuobaosuhuang 00140068JiangX-14Ruijin Jiangxi 0.9950.005Group 1Huangyumi 00140072JiangX-15Xinfeng Jiangxi 0.9960.004Group 1Wuningyumi 00140002JiangX-16Jiujiang Jiangxi 0.0590.941Group 2Tianyumi 00140005JiangX-17Shangrao Jiangxi 0.0020.998Group 2Y umi 00140006JiangX-18Shangrao Jiangxi 0.0310.969Group 2Baiyiumi 00140012JiangX-19Maoyuan Jiangxi 0.0060.994Group 260riyumi 00140016JiangX-20Maoyuan Jiangxi 0.0020.998Group 2Shanyumi 00140019JiangX-21Dexing Jiangxi 0.0050.995Group 2Laorenya 00090002ShangH-01Chongming Shanghai 0.0050.995Group 2Jinmeihuang 00090004ShangH-02Chongming Shanghai 0.0020.998Group 2Zaobaiyumi 00090006ShangH-03Chongming Shanghai 0.0020.998Group 2Chengtuohuang 00090007ShangH-04Chongming Shanghai 0.0780.922Group 2Benyumi (Huang)00090008ShangH-05Shangshi Shanghai 0.0020.998Group 2Bendiyumi 00090010ShangH-06Shangshi Shanghai 0.0040.996Group 2Baigengyumi 00090011ShangH-07Jiading Shanghai 0.0020.998Group 2Huangnuoyumi 00090012ShangH-08Jiading Shanghai 0.0040.996Group 2Huangdubaiyumi 00090013ShangH-09Jiading Shanghai 0.0440.956Group 2Bainuoyumi 00090014ShangH-10Chuansha Shanghai 0.0010.999Group 2Laorenya 00090015ShangH-11Shangshi Shanghai 0.0100.990Group 2Xiaojinhuang 00090016ShangH-12Shangshi Shanghai 0.0050.995Group 2Gengbaidayumi 00090017ShangH-13Shangshi Shanghai 0.0020.998Group 2Nongmeiyihao 00090018ShangH-14Shangshi Shanghai 0.0540.946Group 2Chuanshazinuo 00090020ShangH-15Chuansha Shanghai 0.0550.945Group 2Baoanshanyumi 00110004ZheJ-01Jiangshan Zhejiang 0.0130.987Group 2Changtaixizi 00110005ZheJ-02Jiangshan Zhejiang 0.0020.998Group 2Shanyumibaizi 00110007ZheJ-03Jiangshan Zhejiang 0.0020.998Group 2Kaihuajinyinbao 00110017ZheJ-04Kaihua Zhejiang 0.0100.990Group 2Table 1 (Continued from the preceding page)PGS revealed by Structure 1) NJ dendragram revealed Group1 Group2 by phylogenetic analysisAccession name Entry code Analyzing code Origin (county/city)Province/RegoinAnalysis of Genetic Diversity and Population Structure of Maize Landraces from the South Maize Region of China 1255Liputianzi00110038ZheJ-05Jinhua Zhejiang 0.0020.998Group 2Jinhuaqiuyumi 00110040ZheJ-06Jinhua Zhejiang 0.0050.995Group 2Pujiang80ri 00110069ZheJ-07Pujiang Zhejiang 0.0210.979Group 2Dalihuang 00110076ZheJ-08Yongkang Zhejiang 0.0140.986Group 2Ziyumi00110077ZheJ-09Yongkang Zhejiang 0.0020.998Group 2Baiyanhandipinzhong 00110078ZheJ-10Yongkang Zhejiang 0.0030.997Group 2Duosuiyumi00110081ZheJ-11Wuyi Zhejiang 0.0020.998Group 2Chun’an80huang 00110084ZheJ-12Chun’an Zhejiang 0.0020.998Group 2120ribaiyumi 00110090ZheJ-13Chun’an Zhejiang 0.0020.998Group 2Lin’anliugu 00110111ZheJ-14Lin’an Zhejiang 0.0030.997Group 2Qianhuangyumi00110114ZheJ-15Lin’an Zhejiang 0.0030.997Group 2Fenshuishuitianyumi 00110118ZheJ-16Tonglu Zhejiang 0.0410.959Group 2Kuihualiugu 00110119ZheJ-17Tonglu Zhejiang 0.0030.997Group 2Danbaihuang 00110122ZheJ-18Tonglu Zhejiang 0.0020.998Group 2Hongxinma 00110124ZheJ-19Jiande Zhejiang 0.0030.997Group 2Shanyumi 00110136ZheJ-20Suichang Zhejiang 0.0030.997Group 2Bai60ri 00110143ZheJ-21Lishui Zhejiang 0.0050.995Group 2Zeibutou 00110195ZheJ-22Xianju Zhejiang 0.0020.998Group 2Kelilao00110197ZheJ-23Pan’an Zhejiang 0.0600.940Group 21)The figures refered to the proportion of membership that each landrace possessed.Table 1 (Continued from the preceding page)PGS revealed by Structure 1) NJ dendragram revealed Group 1 Group 2 by phylogenetic analysisAccession name Entry code Analyzing code Origin (county/city)Province/Regoin Table 2 Construction of two phylogenetic groups (SSR-clustered groups) and their correlation with geographical locationsGeographical location SSR-clustered groupChi-square testGroup 1Group 2Total Guangdong 2222 χ2 = 124.89Hainan 1818P < 0.0001Jiangxi 15621Anhui 1414Fujian 1717Jiangsu 1313Shanghai 1515Zhejiang 2323Total5588143by the software of Excel MicroSatellite toolkit (Park 2001). Average number of alleles per locus was calcu-lated by the formula rAA rj j¦1, with the standarddeviation of1)()(12¦ r A AA rj jV , where A j was thenumber of distinct alleles at locus j , and r was the num-ber of loci (Park 2001).Unbiased gene diversity also known as expected heterozygosity, observed heterozygosity for each lo-cus and average gene diversity across the 54 SSR loci,as well as model-based groupings inferred by Struc-ture ver. 2.2, were calculated by the softwarePowerMarker ver.3.25 (Liu et al . 2005). Unbiased gene diversity for each locus was calculated by˅˄¦ 2ˆ1122ˆi x n n h , where 2ˆˆ2ˆ2¦¦z ji ijij i X X x ,and ij X ˆwas the frequency of genotype A i A jin the sample, and n was the number of individuals sampled.The average gene diversity across 54 loci was cal-culated as described by Nei (1987) as follows:rh H rj j ¦1ˆ, with the variance ,whereThe average observed heterozygosity across the en-tire loci was calculated as described by (Hedrick 1983)as follows: r jrj obsobs n h h ¦1, with the standard deviationrn h obs obsobs 1V1256LIU Zhi-zhai et al.Phylogenetic analysis and population genetic structureRelationships among all of the 143 accessions collected from SR were evaluated by using the unweighted pair group method with neighbor-joining (NJ) based on the log transformation of the proportion of shared alleles distance (InSPAD) via PowerMarker ver. 3.25 (FukunagaTable 3 The PIC of each locus and the number of alleles detected by 54 SSRsLocus Bin Repeat motif PIC No. of alleles Description 2)bnlg1007y51) 1.02AG0.7815Probe siteumc1122 1.06GGT0.639Probe siteumc1147y41) 1.07CA0.2615Probe sitephi961001) 2.00ACCT0.298Probe siteumc1185 2.03GC0.7215ole1 (oleosin 1)phi127 2.08AGAC0.577Probe siteumc1736y21) 2.09GCA T0.677Probe sitephi453121 3.01ACC0.7111Probe sitephi374118 3.03ACC0.477Probe sitephi053k21) 3.05A TAC0.7910Probe sitenc004 4.03AG0.4812adh2 (alcohol dehydrogenase 2)bnlg490y41) 4.04T A0.5217Probe sitephi079 4.05AGATG0.495gpc1(glyceraldehyde-3-phosphate dehydrogenase 1) bnlg1784 4.07AG0.6210Probe siteumc1574 4.09GCC0.719sbp2 (SBP-domain protein 2)umc1940y51) 4.09GCA0.4713Probe siteumc1050 4.11AA T0.7810cat3 (catalase 3)nc130 5.00AGC0.5610Probe siteumc2112y31) 5.02GA0.7014Probe sitephi109188 5.03AAAG0.719Probe siteumc1860 5.04A T0.325Probe sitephi085 5.07AACGC0.537gln4 (glutamine synthetase 4)phi331888 5.07AAG0.5811Probe siteumc1153 5.09TCA0.7310Probe sitephi075 6.00CT0.758fdx1 (ferredoxin 1)bnlg249k21) 6.01AG0.7314Probe sitephi389203 6.03AGC0.416Probe sitephi299852y21) 6.07AGC0.7112Probe siteumc1545y21)7.00AAGA0.7610hsp3(heat shock protein 3)phi1127.01AG0.5310o2 (opaque endosperm 2)phi4207018.00CCG0.469Probe siteumc13598.00TC0.7814Probe siteumc11398.01GAC0.479Probe siteumc13048.02TCGA0.335Probe sitephi1158.03A TAC0.465act1(actin1)umc22128.05ACG0.455Probe siteumc11218.05AGAT0.484Probe sitephi0808.08AGGAG0.646gst1 (glutathione-S-transferase 1)phi233376y11)8.09CCG0.598Probe sitebnlg12729.00AG0.8922Probe siteumc20849.01CTAG0.498Probe sitebnlg1520k11)9.01AG0.5913Probe sitephi0659.03CACCT0.519pep1(phosphoenolpyruvate carboxylase 1)umc1492y131)9.04GCT0.2514Probe siteumc1231k41)9.05GA0.2210Probe sitephi1084119.06AGCT0.495Probe sitephi4488809.06AAG0.7610Probe siteumc16759.07CGCC0.677Probe sitephi041y61)10.00AGCC0.417Probe siteumc1432y61)10.02AG0.7512Probe siteumc136710.03CGA0.6410Probe siteumc201610.03ACAT0.517pao1 (polyamine oxidase 1)phi06210.04ACG0.337mgs1 (male-gametophyte specific 1)phi07110.04GGA0.515hsp90 (heat shock protein, 90 kDa)1) These primers were provided by Beijing Academy of Agricultural and Forestry Sciences (Beijing, China).2) Searched from Analysis of Genetic Diversity and Population Structure of Maize Landraces from the South Maize Region of China1257et al. 2005). The unrooted phylogenetic tree was finally schematized with the software MEGA (molecular evolu-tionary genetics analysis) ver. 3.1 (Kumar et al. 2004). Additionally, a chi-square test was used to reveal the correlation between the geographical origins and SSR-clustered groups through FREQ procedure implemented in SAS ver. 9.0 (2002, SAS Institute, Inc.).In order to reveal the population genetic structure (PGS) of 143 landrace accessions, a Bayesian approach was firstly applied to determine the number of groups (K) that these materials should be assigned by the soft-ware BAPS (Bayesian Analysis of Population Structure) ver.5.1. By using BAPS, a fixed-K clustering proce-dure was applied, and with each separate K, the num-ber of runs was set to 100, and the value of log (mL) was averaged to determine the appropriate K value (Corander et al. 2003; Corander and Tang 2007). Since the number of groups were determined, a model-based clustering analysis was used to assign all of the acces-sions into the corresponding groups by an admixture model and a correlated allele frequency via software Structure ver.2.2 (Pritchard et al. 2000; Falush et al. 2007), and for the given K value determined by BAPS, three independent runs were carried out by setting both the burn-in period and replication number 100000. The threshold probability assigned individuals into groupswas set by 0.8 (Liu et al. 2003). The PGS result carried out by Structure was visualized via Distruct program ver. 1.1 (Rosenberg 2004).RESULTSGenetic diversityA total of 517 alleles were detected by the whole set of54 SSRs covering the entire maize genome through all of the 143 maize landraces, with an average of 9.57 alleles per locus and ranged from 4 (umc1121) to 22 (bnlg1272) (Table 3). Among all the alleles detected, the number of distinct alleles accounted for 132 (25.53%), with an av-erage of 2.44 alleles per locus. The distinct alleles dif-fered significantly among the landraces from different provinces/regions, and the landraces from Guangdong, Fujian, Zhejiang, and Shanghai possessed more distinct alleles than those from the other provinces/regions, while those from southern Anhui possessed the lowest distinct alleles, only counting for 3.28% of the total (Table 4).Table 4 The genetic diversity within eight provinces/regions and groups revealed by 54 SSRsProvince/Region Sample size Allele no.1)Distinct allele no.Gene diversity (expected heterozygosity)Observed heterozygosity Anhui14 4.28 (4.19) 69 (72.4)0.51 (0.54)0.58 (0.58)Fujian17 4.93 (4.58 80 (79.3)0.56 (0.60)0.63 (0.62)Guangdong22 5.48 (4.67) 88 (80.4)0.57 (0.59)0.59 (0.58)Hainan18 4.65 (4.26) 79 (75.9)0.53 (0.57)0.55 (0.59)Jiangsu13 4.24 700.500.55Jiangxi21 4.96 (4.35) 72 (68.7)0.56 (0.60)0.68 (0.68)Shanghai15 5.07 (4.89) 90 (91.4)0.55 (0.60)0.55 (0.55)Zhejiang23 5.04 (4.24) 85 (74)0.53 (0.550.60 (0.61)Total/average1439.571320.610.60GroupGroup 155 6.63 (6.40) 91 (89.5)0.57 (0.58)0.62 (0.62)Group 2887.94 (6.72)110 (104.3)0.57 (0.57)0.59 (0.58)Total/Average1439.571320.610.60Provinces/Regions within a groupGroup 1Total55 6.69 (6.40) 910.57 (0.58)0.62 (0.62)Guangdong22 5.48 (4.99) 86 (90.1)0.57 (0.60)0.59 (0.58)Hainan18 4.65 (4.38) 79 (73.9)0.53 (0.56)0.55 (0.59)Jiangxi15 4.30 680.540.69Group 2Total887.97 (6.72)110 (104.3)0.57 (0.57)0.59 (0.58)Anhui14 4.28 (3.22) 69 (63.2)0.51 (0.54)0.58 (0.57)Fujian17 4.93 (3.58) 78 (76.6)0.56 (0.60)0.63 (0.61)Jiangsu13 4.24 (3.22) 71 (64.3)0.50 (0.54)0.55 (0.54)Jiangxi6 3.07 520.460.65Shanghai15 5.07 (3.20) 91 (84.1)0.55 (0.60)0.55 (0.54)Zhejiang23 5.04 (3.20) 83 (61.7)0.53 (0.54)0.60 (0.58)1258LIU Zhi-zhai et al.Among the 54 loci used in the study, 16 (or 29.63%) were dinucleotide repeat SSRs, which were defined as type class I-I, the other 38 loci were SSRs with a longer repeat motifs, and two with unknown repeat motifs, all these 38 loci were defined as the class of I-II. In addition, 15 were located within certain functional genes (defined as class II-I) and the rest were defined as class II-II. The results of comparison indicated that the av-erage number of alleles per locus captured by class I-I and II-II were 12.88 and 10.05, respectively, which were significantly higher than that by type I-II and II-I (8.18 and 8.38, respectively). The gene diversity re-vealed by class I-I (0.63) and II-I (0.63) were some-what higher than by class I-II (0.60) and II-II (0.60) (Table 5).Genetic relationships of the core landraces Overall, 143 landraces were clustered into two groups by using neighbor-joining (NJ) method based on InSPAD. All the landraces from provinces of Guangdong and Hainan and 15 of 21 from Jiangxi were clustered together to form group 1, and the other 88 landraces from the other provinces/regions formed group 2 (Fig.-B). The geographical origins of all these 143 landraces with the clustering results were schematized in Fig.-D. Revealed by the chi-square test, the phylogenetic results (SSR-clustered groups) of all the 143 landraces from provinces/regions showed a significant correlation with their geographical origin (χ2=124.89, P<0.0001, Table 2).Revealed by the phylogenetic analysis based on the InSPAD, the minimum distance was observed as 0.1671 between two landraces, i.e., Tianhongyumi (JiangX-03) and Hongganshanyumi (JiangX-04) collected from Jiangxi Province, and the maximum was between two landraces of Huangbaosu (FuJ-16) and Hongyumi (HaiN-14) collected from provinces of Fujian and Hainan, respectively, with the distance of 1.3863 (data not shown). Two landraces (JiangX-01 and JiangX-21) collected from the same location of Dexing County (Table 1) possessing the same names as Shanyumi were separated to different groups, i.e., JiangX-01 to group1, while JiangX-21 to group 2 (Table 1). Besides, JiangX-01 and JiangX-21 showed a rather distant distance of 0.9808 (data not shown). These results indicated that JiangX-01 and JiangX-21 possibly had different ances-tral origins.Population structureA Bayesian method was used to detect the number of groups (K value) of the whole set of landraces from SR with a fixed-K clustering procedure implemented in BAPS software ver. 5.1. The result showed that all of the 143 landraces could also be assigned into two groups (Fig.-A). Then, a model-based clustering method was applied to carry out the PGS of all the landraces via Structure ver. 2.2 by setting K=2. This method as-signed individuals to groups based on the membership probability, thus the threshold probability 0.80 was set for the individuals’ assignment (Liu et al. 2003). Accordingly, all of the 143 landraces were divided into two distinct model-based groups (Fig.-C). The landraces from Guangdong, Hainan, and 15 landraces from Jiangxi formed one group, while the rest 6 landraces from the marginal countries of northern Jiangxi and those from the other provinces formed an-other group (Table 1, Fig.-D). The PGS revealed by the model-based approach via Structure was perfectly consistent with the relationships resulted from the phy-logenetic analysis via PowerMarker (Table 1).DISCUSSIONThe SR includes eight provinces, i.e., southern Jiangsu and Anhui, Shanghai, Zhejiang, Fujian, Jiangxi, Guangdong, and Hainan (Fig.-C), with the annual maize growing area of about 1 million ha (less than 5% of theTable 5 The genetic diversity detected with different types of SSR markersType of locus No. of alleles Gene diversity Expected heterozygosity PIC Class I-I12.880.630.650.60 Class I-II8.180.600.580.55 Class II-I8.330.630.630.58。
体外哺乳动物细胞基因突变试验的英语
体外哺乳动物细胞基因突变试验的英语Gene mutation is a crucial process in the evolution of species, as it introduces genetic diversity and drives adaptation to changing environments. In the field of molecular biology, researchers often conduct gene mutation experiments on mammalian cells to study the effects of specific genetic changes on cellular function. One commonly used method for studying gene mutations in mammalian cells is the in vitro mammalian cell gene mutation assay.The in vitro mammalian cell gene mutation assay is a widely accepted and standardized test for assessing the mutagenic potential of chemicals and other substances. This assay is based on the principle that mutations in specific genes can lead to changesin cellular phenotype, such as altered growth characteristics or resistance to certain toxins. By exposing mammalian cells to a test substance and then monitoring for genetic changes, researchers can determine the mutagenic potential of the substance in question.To conduct an in vitro mammalian cell gene mutation assay, researchers typically start by selecting a suitable mammalian cell line for the experiment. Commonly used cell lines include Chinese hamster ovary (CHO) cells, L5178Y mouse lymphoma cells, and TK6 human lymphoblastoid cells. These cell lines are chosen for their sensitivity to genetic changes and their ability to accurately reflect the mutagenic potential of test substances.Once a cell line has been selected, researchers expose the cells to varying concentrations of the test substance and incubate them for a specified period of time. During this incubation period, the cells are allowed to replicate and divide, giving them the opportunity to accumulate genetic mutations. After the incubation period, researchers can assess the presence of gene mutations by performing molecular analyses, such as polymerase chain reaction (PCR) or DNA sequencing.The results of an in vitro mammalian cell gene mutation assay can provide valuable information about the potential mutagenic effects of a test substance. If the test substance induces a significant increase in the frequency of gene mutations in the treated cellscompared to untreated controls, it may be considered mutagenic. This information is important for assessing the safety of chemicals and other substances, as mutagenic compounds have the potential to cause genetic damage and increase the risk of cancer.In conclusion, the in vitro mammalian cell gene mutation assay is a powerful tool for studying the mutagenic potential of chemicals and other substances. By exposing mammalian cells to test substances and monitoring for genetic changes, researchers can gain valuable insights into the effects of specific genetic mutations on cellular function. This assay plays a crucial role in assessing the safety of chemicals and informing regulatory decisions to protect human health and the environment.。
益智种质资源表型性状的遗传多样性分析
热带作物学报2022, 43(1): 094 100Chinese Journal of Tropical Crops益智种质资源表型性状的遗传多样性分析李英英1，郑云柯2，晏小霞1，王清隆1，羊青1，汤欢1，王茂媛1，王祝年1*1. 中国热带农业科学院热带作物品种资源研究所，海南海口 571101；2. 中国热带农业科学院热带生物技术研究所，海南海口 571101摘要：对收集的90份益智种质资源的18个表型性状进行遗传多样性分析，以期为益智品种改良和种质创新提供依据。
结果表明：供试的益智种质具有丰富的遗传多样性，质量性状中多样性指数最高的为果形（1.1507），数量性状中多样性指数最高的为株高（2.0700），变异系数最大的为结果枝数（41.32%）；提取的6个主成分累计贡献率为68.339%，第一主成分主要反映的是益智植株的叶片形态和株高，第二主成分主要反映的是益智外观形态及生长状态，第三主成分主要反映的是益智植株的分枝状况，第四主成分主要反映的是益智的产量，第五主成分主要反映的是益智的花果量，第六主成分主要反映的是益智的果产量。
通过聚类分析将供试材料划分为4大类群，其中第I类群可作为益智抗倒伏及矮化品种进行开发，第II类群可作为益智品种改良和杂交育种的材料，第III类群可作为益智育种生产材料，第IV类群可用于观赏益智材料的筛选。
本研究为益智优异种质筛选、资源合理利用、品种改良和品种选育提供参考依据。
关键词：益智；表型性状；种质资源；遗传多样性中图分类号：S326 文献标识码：AGenetic Diversity Analysis of Alpinia oxyphylla Germplasm Resourcesby Phenotypic TraitsAll Rights Reserved.LI Yingying1, ZHENG Yunke2, YAN Xiaoxia1, WANG Qinglong1, YANG Qing1, TANG Huan1,WANG Maoyuan1, WANG Zhunian1*1. Tropical Crops Genetic Resources Institute, Chinese Academy of Tripical Agricultural Sciences, Haikou, Hainan 571101, China;2. Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101,ChinaAbstract: The genetic diversity by 18 phenotypic traits of 90 Alpinia oxyphylla germplasm resources was analyzed toprovide the basis for the improvement and germplasm innovation of Alpinia oxyphylla varieties. The genetic diversitywas rich in the germplasms. In qualitative traits, the highest Shannon-Wiener diversity index was for fruit shape(1.1507). In quantitative traits, the highest genetic diversity indexes were for plant height (2.0700), the highest coeffi-cient variation (CV) was for the branch number of fruit (41.32%). The cumulative contribution rate of the first 6 princi-pal components was 68.339%. The first principal component mainly reflected the leaf shape and plant height. The sec-ond principal component mainly reflected the appearance and growth state. The third principal component mainly re-flected the branching status. The fourth principal component mainly reflected the output. The fifth principal componentmainly reflected the amount of fruit. The sixth principal component mainly reflected the fruit yield. The experimentalmaterials were divided into four groups by cluster analysis. Group I could be developed as lodging resistant and dwarf-ing varieties. Group II could be used as the material for improvement and cross breeding. Group III could be used as theproduction material. The fourth group could be used for the screening of ornamental materials. This study would providea basis for the selection of excellent germplasm, rational utilization of resources, variety improvement and breed selection.收稿日期 2021-03-26；修回日期 2021-05-23基金项目 海南省自然科学基金项目“海南岛益智资源调查与品质评价研究”（No. 820QN344）；海南省农业农村厅农业种质资源保护项目“南药种质资源保护”（No. NYBH2021）。
Rice Plant Genome Genetic Diversity
Rice Plant Genome Genetic Diversity Rice is one of the most important staple crops in the world, providing food for billions of people. The rice plant genome is a complex structure that contains a vast amount of genetic diversity. This genetic diversity is essential for the survival of rice plants and for the development of new and improved rice varieties. In this essay, we will explore the importance of genetic diversity in the rice plant genome, its impact on rice production, and the challenges associated with maintaining and conserving this diversity.Genetic diversity is the variation in the genetic makeup of individuals within a species. In the case of the rice plant genome, genetic diversity is crucial for the plant's survival and adaptation to changing environmental conditions. The rice plant genome is highly diverse due to its long history of domestication and the natural selection process. The domestication of rice began over 10,000 years ago, and since then, rice has been cultivated in different regions of the world, resulting in the development of various rice varieties with unique genetic traits.The genetic diversity in the rice plant genome has a significant impact on rice production. Different rice varieties have varying levels of resistance to pests and diseases, tolerance to environmental stresses such as drought and flooding, and different grain qualities. For example, some rice varieties have a higher yield potential than others, while some have better grain quality for specific purposes such as making sushi or rice cakes. Therefore, the genetic diversity in the rice plant genome provides a valuable resource for developing new and improved rice varieties that can meet the diverse needs of consumers and farmers.However, the genetic diversity in the rice plant genome is under threat due to various factors such as climate change, land-use changes, and the intensification of rice production. These factors can lead to the loss of traditional rice varieties and the homogenization of rice production systems. The loss of genetic diversity in the rice plant genome can have severe consequences for rice production, as it reduces the plant's ability to adapt to changing environmental conditions and increases its susceptibility to pests and diseases.To maintain and conserve the genetic diversity in the rice plant genome, various conservation strategies have been developed. These strategies include in situ conservation, ex situ conservation, and the use of participatory plant breeding. In situ conservation involves the conservation of rice varieties in their natural habitat, while ex situ conservation involves the preservation of rice seeds in gene banks. Participatory plant breeding involves the involvement of farmers in the selection and breeding of new rice varieties, which helps to maintain the genetic diversity of rice plants and promotes the use of traditional knowledge in rice production.In conclusion, the genetic diversity in the rice plant genome is essential for the survival and adaptation of rice plants to changing environmental conditions. It also provides a valuable resource for developing new and improved rice varieties that can meet the diverse needs of consumers and farmers. However, the genetic diversity in the rice plant genome is under threat due to various factors, and it is essential to maintain and conserve this diversity to ensure the sustainability of rice production. Conservation strategies such as in situ conservation, ex situ conservation, and participatory plant breeding can help to maintain the genetic diversity of rice plants and promote the sustainable use of traditional knowledge in rice production.。
高黎贡山种子植物物种丰富度沿海拔梯度的变化
高黎贡山种子植物物种丰富度沿海拔梯度的变化王志恒 陈安平 朴世龙 方精云3(北京大学环境学院生态学系,北京大学生态学研究与教育中心,北京大学地表过程分析与模拟教育部重点实验室, 北京 100871)摘要:物种丰富度沿海拔梯度的分布格局成为生物多样性研究的热点。
为探讨中尺度区域物种丰富度沿海拔梯度的分布,本文以高黎贡山为研究对象,利用该地区的地方植物志资料,结合通过GIS 生成的区域数字高程模型(DEM )数据,分析了该区域全部种子植物和乔木、灌木、草本三种生活型种子植物物种丰富度的垂直分布格局以及物种密度沿海拔梯度的变化特征。
结果表明:(1)全部种子植物和不同生活型植物物种丰富度随着海拔的升高呈现先增加后减小的趋势,最大值出现在海拔1500-2000m 的范围;(2)物种密度与海拔也呈现单峰曲线关系;(3)物种丰富度和物种密度分布格局的形成主要受海拔所反映的水、热状况组合以及物种分布的边界影响。
关键词:物种丰富度,物种密度,生活型,垂直格局,海拔梯度,地形中图分类号:Q948 文献标识码:A 文章编号:1005-0094(2004)01-0082-07Pattern of species richness along an altitudinal gradient on G aoligongMountains ,Southw est ChinaWAN G Zhi 2Heng ,CHEN An 2Ping ,PIAO Shi 2Long ,FAN G Jing 2Yun 3Depart ment of Ecology ,College of Envi ronmental Sciences ,Center f or Ecological Research &Edu 2cation ,and Key L aboratory f or Earth S urf ace Processes of the M i nist ry of Education ,Peki ng U ni 2versity ,Beiji ng 100871Abstract :Patterns of s pecies richness along altitudinal gradients have bec ome a focus of ec ological research.W e ex 2plored the patterns of seed plants richness along an altitudinal gradient on G a olig ong M ountains ,S outhwest China.In formation on seed plants and their distribution ranges was c ollected from Flora of Gaoligong Mountains ,and the DEM (Digital E levation M odel )was derived from a topographical map of this ing these datasets ,altitudinal patterns of richness and s pecies density of all seed plant s pecies and plants of three different life forms (trees ,shrubs and herbaceous plants ),as well as their relationship with topographic parameters were studied.The results are sum 2marized as follows:(1)the s pecies richness increased ra pidly first and then decreased with increasing elevation ,peak 2ing at the altitudes of between 1500m and 2000m;(2)sim ilar to the altitudinal pattern of s pecies richness ,s pecies ,genus and fam ily densities (number of taxa per unit area )als o sh owed a hum ped pattern along the altitudinal gradi 2ent.S pecies density reached a maximum between 1500m and 2000m ,with an average of 1653m ,while genus and fam ily densities peaked between 900-1500m ,with an average of 1089m ,and (3)energy and m oisture represented by elevation ,as well as hard b oundaries of s pecies distribution were possible factors determ ining the patterns of s pecies richness and density.K ey w ords :species richness ,species density ,life form ,altitudinal pattern ,altitudinal gradient ,to 2pography 物种丰富度(species richness )及其分布格局是生物多样性研究的一个重要内容(贺金生,马克平,1997)。
自然基因多样性作文英语
自然基因多样性作文英语The Importance of Genetic Diversity in Nature。
Genetic diversity is the variety of different types of genes in a species or population. It is an essential component of biodiversity and plays a crucial role in the health and resilience of ecosystems. In nature, genetic diversity helps species adapt to changing environmental conditions, resist diseases, and maintain stable populations. Without genetic diversity, species would be more susceptible to extinction and the overall balance of ecosystems would be disrupted.One of the key benefits of genetic diversity is itsrole in adaptation. When environmental conditions change, species with a wide range of genetic variation are more likely to have individuals that can survive and reproduce in the new conditions. This allows the species to adapt and evolve over time, ensuring its survival in the face of environmental challenges. For example, in a population ofplants, those with diverse genetic traits may be morelikely to survive a drought, as some individuals may have genes that make them more resistant to water scarcity.Furthermore, genetic diversity is important for disease resistance. When a population has a wide range of genetic variation, it is less likely that a single disease will wipe out the entire population. Some individuals may be naturally resistant to the disease due to their genetic makeup, and they can pass on this resistance to their offspring. This helps to maintain the overall health of the population and reduces the risk of widespread disease outbreaks.In addition, genetic diversity is crucial for maintaining stable populations. Inbreeding, which occurs when individuals within a population mate with close relatives, can lead to a loss of genetic diversity and an increase in genetic disorders. By contrast, populations with high genetic diversity are more likely to have individuals with traits that make them well-suited to their environment, leading to healthier and more stablepopulations.Unfortunately, human activities such as habitat destruction, pollution, and climate change are putting pressure on many species and reducing their genetic diversity. As a result, many species are facing increased risks of extinction and are less able to adapt to changing environmental conditions. Conservation efforts are therefore essential to protect genetic diversity in nature and ensure the long-term survival of species.There are several ways in which genetic diversity can be conserved. One approach is to protect and restore natural habitats, as this helps to maintain healthy populations of wild species and allows them to continue evolving in their natural environments. In addition, captive breeding programs can be used to maintain genetic diversity in at-risk species, providing a safety net against extinction. These programs involve carefully managing the breeding of individuals to maintain as much genetic diversity as possible, with the goal of eventually reintroducing individuals into the wild.Overall, genetic diversity is a fundamental component of healthy ecosystems and is essential for the long-term survival of species. By understanding the importance of genetic diversity and taking steps to conserve it, we can help to ensure the health and resilience of natural ecosystems for future generations. It is crucial that we continue to prioritize the conservation of genetic diversity in nature, as it is key to maintaining the balance and stability of our planet's ecosystems.。
谈谈个人对转基因的看法的英语作文
谈谈个人对转基因的看法的英语作文英文回答：Genetic modification is a transformative technologythat has the potential to revolutionize agriculture, medicine, and other fields. However, concerns over its safety and ethical implications have sparked ongoing debates.Proponents of genetic modification emphasize its benefits. It can increase crop yields, making food production more efficient and sustainable. It can also improve the nutritional value of food, helping to address malnutrition and disease. In medicine, genetic modification offers promising treatments for genetic disorders and chronic diseases, such as cancer.Opponents of genetic modification, on the other hand, raise concerns about its potential risks. They argue that genetically modified organisms (GMOs) could have unintendedconsequences on the environment, such as altering ecosystems or creating new superweeds. There are also concerns about the potential health effects of consuming GMOs, although scientific evidence to date has not found conclusive evidence of harm.Ethical considerations also factor into the debate. Some argue that genetic modification crosses a line into altering the natural world, and that it raises questions about our role as stewards of the environment. Others believe that genetic modification is a tool that can be used responsibly to improve human well-being.Ultimately, the decision of whether or not to support genetic modification is a complex one that requires a balancing of potential benefits and risks. It is important to engage in informed discussions based on scientific evidence and ethical considerations.中文回答：转基因技术是一种变革性的技术，它具有改变农业、医学和其他领域的潜力。
益生菌肠道微生物的基因组学英文论文及翻译
The genomics of probiotic intestinal microorganismsSeppo Salminen1 , Jussi Nurmi2 and Miguel Gueimonde1(1) Functional Foods Forum, University of Turku, FIN-20014 Turku, Finland(2) Department of Biotechnology, University of Turku, FIN-20014 Turku, FinlandSeppo SalminenEmail: *********************Published online: 29 June 2005AbstractAn intestinal population of beneficial commensal microorganisms helps maintain human health, and some of these bacteria have been found to significantly reduce the risk of gut-associated disease and to alleviate disease symptoms. The genomic characterization of probiotic bacteria and other commensal intestinal bacteria that is now under way will help to deepen our understanding of their beneficial effects.While the sequencing of the human genome [1, 2] has increased ourunderstanding of the role of genetic factors in health and disease, each human being harbors many more genes than those in their own genome. These belong to our commensal and symbiotic intestinal microorganisms - our intestinal 'microbiome' - which play an important role in maintaining human health and well-being. A more appropriate image of ourselves would be drawn if the genomes of our intestinal microbiota were taken into account. The microbiome may contain more than 100 times the number of genes in the human genome [3] and provides many functions that humans have thus not needed to develop themselves. The indigenous intestinal microbiota provides a barrier against pathogenic bacteria and other harmful food components [4–6]. It has also been shown to have a direct impact on the morphology of the gut [7], and many intestinal diseases can be linked to disturbances in the intestinal microbial population [8].The indigenous microbiota of an infant's gastrointestinal tract is originally created through contact with the diverse microbiota of the parents and the immediate environment. During breast feeding, initial microbial colonization is enhanced by galacto-oligosaccharides in breast milk and contact with the skin microbiota of the mother. This early colonization process directs the microbial succession until weaning and forms the basis for a healthy microbiota. The viable microbes in the adultintestine outnumber the cells in the human body tenfold, and the composition of this microbial population throughout life is unique to each human being. During adulthood and aging the composition and diversity of the microbiota can vary as a result of disease and the genetic background of the individual.Current research into the intestinal microbiome is focused on obtaining genomic data from important intestinal commensals and from probiotics, microorganisms that appear to actively promote health. This genomic information indicates that gut commensals not only derive food and other growth factors from the intestinal contents but also influence their human hosts by providing maturational signals for the developing infant and child, as well as providing signals that can lead to an alteration in the barrier mechanisms of the gut. It has been reported that colonization by particular bacteria has a major role in rapidly providing humans with energy from their food [9]. For example, the intestinal commensal Bacteroides thetaiotaomicron has been shown to have a major role in this process, and whole-genome transcriptional profiling of the bacterium has shown that specific diets can be associated with selective upregulation of bacterial genes that facilitate delivery of products of carbohydrate breakdown to the host's energy metabolism [10, 11]. Key microbial groups in the intestinal microbiota are highly flexible in adapting to changes in diet, and thus detailed prediction of their actions and effects may be difficult. Although genomic studies have revealed important details about the impact of the intestinal microbiota on specific processes [3, 11–14], the effects of species composition and microbial diversity and their potential compensatory functions are still not understood.Probiotics and healthA probiotic has been defined by a working group of the International Life Sciences Institute Europe (ILSI Europe) as "a viable microbial food supplement which beneficially influences the health of the host" [15]. Probiotics are usually members of the healthy gut microbiota and their addition can assist in returning a disturbed microbiota to its normal beneficial composition. The ILSI definition implies that safety and efficacy must be scientifically demonstrated for each new probiotic strain and product. Criteria for selecting probiotics that are specific for a desired target have been developed, but general criteria that must be satisfied include the ability to adhere to intestinal mucosa and tolerance of acid and bile. Such criteria have proved useful but cumbersome in current selection processes, as there are several adherence mechanisms and they influence gene upregulation differently in the host. Therefore, two different adhesion studies need to be conducted on each strain and theirpredictive value for specific functions is not always good or optimal. Demonstration of the effects of probiotics on health includes research on mechanisms and clinical intervention studies with human subjects belonging to target groups.The revelation of the human genome sequence has increased our understanding of the genetic deviations that lead to or predispose to gastrointestinal disease as well as to diseases associated with the gut, such as food allergies. In 1995, the first genome of a free-living organism, the bacterium Haemophilus influenzae, was sequenced [16]. Since then, over 200 bacterial genome sequences, mainly of pathogenic microorganisms, have been completed. The first genome of a mammalian lactic-acid bacterium, that of Lactococcus lactis, a microorganism of great industrial interest, was completed in 2001 [17]. More recently, the genomes of numerous other lactic-acid bacteria [18], bifidobacteria [12] and other intestinal microorganisms [13, 19, 20] have been sequenced, and others are under way [21]. Table 1lists the probiotic bacteria that have been sequenced. These great breakthroughs have demonstrated that evolution has adapted both microbes and humans to their current state of cohabitation, or even symbiosis, which is beneficial to both parties and facilitates a healthy and relatively stable but adaptable gut environment.Table 1Lessons from genomesLactic-acid bacteria and bifidobacteria can act as biomarkers of gut health by giving early warning of aberrations that represent a risk of specific gut diseases. Only a few members of the genera Lactobacillus and Bifidobacterium, two genera that provide many probiotics, have been completely sequenced. The key issue for the microbiota, for probiotics, and for their human hosts is the flexibility of the microorganisms in coping with a changeable local environment and microenvironments.This flexibility is emphasized in the completed genomes of intestinal and probiotic microorganisms. The complete genome sequence of the probiotic Lactobacillus acidophilus NCFM has recently been published by Altermann et al. [22]. The genome is relatively small and the bacterium appears to be unable to synthesize several amino acids, vitamins and cofactors. Italso encodes a number of permeases, glycolases and peptidases for rapid uptake and utilization of sugars and amino acids from the human intestine, especially the upper gastrointestinal tract. The authors also report a number of cell-surface proteins, such as mucus- and fibronectin-binding proteins, that enable this strain to adhere to the intestinal epithelium and to exchange signals with the intestinal immune system. Flexibility is guaranteed by a number of regulatory systems, including several transcriptional regulators, six PurR-type repressors and ninetwo-component systems, and by a variety of sugar transporters. The genome of another probiotic, Lactobacillus johnsonii [23], also lacks some genes involved in the synthesis of amino acids, purine nucleotides and numerous cofactors, but contains numerous peptidases, amino-acid permeases and other transporters, indicating a strong dependence on the host.The presence of bile-salt hydrolases and transporters in these bacteria indicates an adaptation to the upper gastrointestinal tract [23], enabling the bacteria to survive the acidic and bile-rich environments of the stomach and small intestine. In this regard, bile-salt hydrolases have been found in most of the sequenced genomes of bifidobacteria and lactic-acid bacteria [24], and these enzymes can have a significant impact on bacterial survival. Another lactic-acid bacterium, Lactobacillus plantarum WCFS1, also contains a large number of genes related to carbohydrate transport and utilization, and has genes for the production of exopolysaccharides and antimicrobial agents [18], indicating a good adaptation to a variety of environments, including the human small intestine [14]. In general, flexibility and adaptability are reflected by a large number of regulatory and transport functions.Microorganisms that inhabit the human colon, such as B. thetaiotaomicron and Bifidobacterium longum [12], have a great number of genes devoted to oligosaccharide transport and metabolism, indicating adaptation to life in the large intestine and differentiating them from, for example, L. johnsonii [23]. Genomic research has also provided initial information on the relationship between components of the diet and intestinal microorganisms. The genome of B. longum [12] suggests the ability to scan for nutrient availability in the lower gastrointestinal tract in human infants. This strain is adapted to utilizing the oligosaccharides in human milk along with intestinal mucins that are available in the colon of breast-fed infants. On the other hand, the genome of L. acidophilus has a gene cluster related to the metabolism of fructo-oligosaccharides, carbohydrates that are commonly used as prebiotics, or substrates to肠道微生物益生菌的基因组学塞波萨米宁，尤西鲁米和米格尔哥尔摩得（1）功能性食品论坛，图尔库大学，FIN-20014芬兰图尔库（2）土尔库大学生物技术系，FIN-20014芬兰图尔库塞波萨米宁电子邮件：seppo.salminen utu.fi线上发表于2005年6月29日摘要肠道有益的共生微生物有助于维护人体健康，一些这些细菌被发现显着降低肠道疾病的风险和减轻疾病的症状。
关于蝴蝶的迁徙行意义 英语作文
The Significance of Butterfly MigrationButterfly migration is a fascinating phenomenon that holds significant meaning in the natural world.It involves the long-distance movement of butterflies from one region to another,often spanning thousands of kilometers.Here are some key points highlighting the significance of butterfly migration:Survival and Reproduction:The primary purpose of butterfly migration is survival and reproduction.Butterflies undertake these long journeys in search of suitable breeding and feeding grounds.By migrating to different regions,butterflies can find abundant food sources,optimal breeding conditions,and suitable habitats for their offspring.Migration increases their chances of survival and ensures the continuation of their species.Genetic Diversity:Butterfly migration plays a crucial role in maintaining genetic diversity within butterfly populations.As butterflies travel to new areas,they encounter different populations and individuals.This mixing of genetic material through mating helps prevent inbreeding and the accumulation of harmful genetic mutations.Genetic diversity enhances the resilience and adaptability of butterfly populations, enabling them to better withstand environmental changes and challenges.Pollination:During their migration,butterflies act as important pollinators.As they visit various flowers for nectar along their journey, they inadvertently transfer pollen from one flower to another, facilitating cross-pollination.This process is crucial for the reproduction of plants,ensuring the production of seeds and the maintenance of plant diversity.Butterfly migration,therefore,contributes to the health and sustainability of ecosystems.Ecological Balance:Butterfly migration helps maintain ecological balance and biodiversity.As butterflies move between different regions,they interact with various plants,animals,and habitats.This interactionpromotes the dispersal of seeds,the transfer of nutrients,and the establishment of new plant communities.Butterflies also serve as a food source for other animals,including birds and reptiles,contributing to the intricate web of life in ecosystems.Scientific Research:The study of butterfly migration provides valuable insights into animal behavior,navigation,and ecological processes. Scientists and researchers use butterfly migration as a model to understand the mechanisms behind long-distance movement, orientation,and the physiological changes that occur during migration. This knowledge can be applied to conservation efforts,habitat restoration,and the protection of migratory species.Aesthetic and Educational Value:Butterfly migration captivates the imagination and curiosity of people around the world.The sight of thousands of butterflies in flight is a spectacle of beauty and wonder.It inspires awe and appreciation for the natural world and encourages individuals to learn more about the intricate relationships between species and their environments.Butterfly migration serves as an educational tool,raising awareness about the importance of conservation and the interconnectedness of ecosystems.In conclusion,butterfly migration holds great significance in the natural world.It ensures the survival and reproduction of butterflies,maintains genetic diversity,facilitates pollination,promotes ecological balance, contributes to scientific research,and holds aesthetic and educational value.Understanding and protecting butterfly migration is crucial for the conservation of these delicate creatures and the preservation of the ecosystems they inhabit.。
提高番木瓜组培苗生根率的培养基配方优化
2022年2月 热带农业科学第42卷第2期Feb. 2022 CHINESE JOURNAL OF TROPICAL AGRICULTURE Vol.42, No.2收稿日期 2021-11-26；修回日期 2021-12-25基金项目 海南天然橡胶产业集群（No.农产发[2020]2号）。
第一作者 成镜（1986—），男，硕士研究生，助理研究员，主要从事热带林木快繁，E-mail ：*****************。
通讯作者 黄天带（1976—），女，博士，副研究员，主要从事橡胶树组织培养与转基因育种，E-mail ：*************************。
提高番木瓜组培苗生根率的培养基配方优化成镜 李季 戴雪梅 徐正伟 周权男 黄天带（中国热带农业科学院橡胶研究所/农业农村部橡胶树生物学与遗传资源利用重点实验室/ 省部共建国家重点实验室培育基地-海南省热带作物栽培生理学重点实验室/热带林木种子种苗工程中心 海南海口 571101）摘 要 以TY-4番木瓜组培芽为试验材料，在以半强度Murashige 和Skoog 培养基为基本培养基，蛭石为支撑物的基础上，研究不同蔗糖浓度（0、5、20、40 g/L ）、吲哚-3-丁酸浓度（2、4、6、8 mg/L ）、间苯三酚浓度（0、10.0、14.9、19.9 mg/L ）对番木瓜生长状态和生根率及根系质量的影响。
结果表明：将番木瓜组培芽在含蔗糖浓度为0，吲哚-3-丁酸（IBA ）浓度为2 mg/L 、间苯三酚浓度为0，并补充1/2强度的MS 大量元素、MS 微量元素、MS 有机质，肌醇0.1 g/L 、硫胺素0.4 mg/L 和核黄素0.38 mg/L ，支撑物为蛭石的培养基中培养时，体外芽最高生根率为95.2%，与最低的生根处理相比，高出38.1%，且茎基部形成愈伤组织较少。
通过正交试验结果分析可知，番木瓜最佳的生根组合为：蔗糖浓度为0、吲哚-3-丁酸（IBA ）浓度为2 mg/L 、间苯三酚浓度为10.0 mg/L 。
三打白骨精改写创意英语作文500字左右
三打白骨精改写创意英语作文500字左右全文共3篇示例，供读者参考篇1The Valiant Monks and the Wicked White Bone Fiend (2,018 words)It was a crisp autumn evening when I first heard the legendary tale of the brave Buddhist monks who defeated the cruel White Bone Fiend. Grandpa's wrinkled face glowed in the firelight as he began to weave the ancient story."A long time ago, there lived a malicious demon spirit known as the White Bone Fiend," Grandpa's voice took on a sinister tone. "This wicked creature feasted upon the flesh and souls of innocent humans, spreading terror across the land."I shuddered, pulling my cloak tighter. Grandpa continued, "One fateful day, the White Bone Fiend happened upon a humble monastery tucked away in the misty mountains. Consumed by evil hunger, it began devouring the monks one by one."The first monk cowered in fear as the towering fiend approached, gnashing its jagged teeth. "P-please spare me, foulbeast!" he cried. The fiend threw back its head and cackled. "And let such a plump meal slip away? I think not, little monk." With one swipe of its claws, the poor monk fell lifeless to the ground.Try as they might, the remaining brethren stood no chance against the fiend's supernatural strength. Within a matter of hours, dozens lay dead or dying. Only three monks had survived by concealing themselves."Those three brave souls were our last hope to defeat the White Bone Fiend," Grandpa said gravely. "Using their mastery of Buddhism and martial arts, they carefully formulated a strategy."The trio spent days fasting, meditating, and preparing talismans imbued with powerful magic. At last, they emerged from seclusion, ready to banish the evil plaguing their monastery."You there! Vile monster!" shouted the eldest monk Po Lun. The fiend turned, nostrils flaring. "Your reign of terror ends now."The beast lunged with a deafening roar, but the monks were ready. Po Lun deflected the attack with a sweep of his staff while the others unleashed a blinding cloud of purification powder. The fiend howled in agony, momentarily stunned.Seizing their chance, the monks formed a circle and began chanting sacred sutras. Their melodic voices resounded through the valley as rays of brilliant light burst forth, bathing the fiend in searing energy. It writhed and screeched, slowly disintegrating.With a thunderous crash, the White Bone Fiend collapsed into a smoldering heap. The monks had triumphed over unspeakable evil through bravery, wisdom and devotion."And that's how a few valiant monks rid our lands of the wretched White Bone Fiend," Grandpa concluded, a proud smile spreading across his weathered face. "Their courageous actions that day became the stuff of legend."I sat in awed silence as the tale came to a close. The dance of shadows cast by the dying embers seemed to mirror the climactic battle Grandpa had just recounted. Though the White Bone Fiend was mere fiction, the monks' extraordinary display of heroism was inspiring beyond words.As I nestled into my sleeping mat that night, visions of the fierce yet righteous warriors danced behind my closed eyelids. In that moment, I vowed to embody their bravery, discipline and nobility in my own life's journey. The path before me remained unknown, but I knew the example of the three conquering monks would give me strength, no matter what evil I might face.篇2The Funky Bones CrewYo, let me tell y'all about the craziest adventure my homies and I had last summer. It all went down when we were chillin' in the park, soaking up some rays. My man Monk was laying down some sick beats on his portable drums when this creepy-looking skeleton rolled up on us.At first, we were like "Whoa, is that the Crypt Keeper?" But then the skeleton started rappin' at us in this crazy high-pitched voice. "Yo bone heads, I'm White Bone Spirit and I run this park! If you don't want to get jacked, you better make like a tree and beat it!"Well, we weren't about to let some calcified crunk punk disrespect us like that. Monk stood up and was like "Oh no you didn't! This is our turf, so take a chill pill bag of bones!"That set White Bone Spirit off good. His jaw dropped and his bones started clanking together like he was having a fit. "You askin' for a beef little monk? I'll bury you and your whole crew!"That's when Pig dropped his hot sauce jar and was like "Say what?! Ain't nobody disrespectin' my peeps like that!" Him andMonkey started poppin' off, whippin' out their nunchuks and nine irons like they were about to shank a fool.White Bone Spirit didn't even flinch though. He just let out this wicked cackle and then BAM! Suddenly there was an army of skeleton homies behind him, armed with bones, bats, and anything else they could find.We started booking it, but those bony punks were wicked fast. We had to pull off all kinds of crazy stunts to escape them - back flips, parkour, you name it. Pig even had to use his Goku Staff to chopper us out of there when we got cornered on the roof.Finally, we lost them in the bamboo forest. As we were trying to catch our breath, Monk was like "Guys, I got this. Just trust me." Then he broke out these crazy incantations and mustard seed clouds started swirling all around us.Next thing I know, we had our own undead army ready to throw down! There were skeletons as far as the eye could see, all bumping their bonedacious bods to Monk's chanting. It was like the Halloween cover of Thriller up in there!Needless to say, when White Bone Spirit and his boneheads came bursting through the trees, they got served harder than anovercooked turkey on Thanksgiving. Our skelly soldiers tore them up with bone-crunching body slams and sick Fu moves. I even saw one of our guys spinning on his shoulders like a break dancer before taking a fool's head off!In the end, we reigned victorious and those punks were only too happy to beat it out of our bamboo battleground. White Bone Spirit was like "You got mad skills monk, this won't be the last you hear from me!" Then he and his compact pack of remaining bones scattered.We celebrated by having Pig whip up his legendary chili con carne. As we chowed down, Monk was like "See guys? A wise monk knows the form is emptiness, and emptiness is form. Don't get it twisted - bones may seem scary, but they're empty inside just like everything else." Deep stuff, bro.That's just how we roll on the real Journey to Enlightenment. Facing down boneheads and hot sauce monsters, all in a day's work! If any more freaky ghouls want to try us, they better be strapped - 'cause we came to drop rhymes, not bones!篇3The Monkey King's Epic Struggle Against Racism and PrejudiceOnce upon a time, in a mystical land, there lived a powerful and mischievous monkey king named Sun Wukong. Despite his incredible strength and magical abilities, Wukong faced constant discrimination and prejudice from other beings simply because of his monkey form.One fateful day, Wukong encountered a vile monster known as the White Bone Demon. This foul creature despised all living things and sought to destroy every last shred of life in her path. The White Bone Demon looked down upon Wukong, mocking his monkey appearance and refusing to take him seriously as a worthy opponent.Enraged by her bigoted taunts, Wukong engaged the demon in an epic battle that shook the very foundations of the earth. Their clashes were so intense that mountains crumbled and rivers changed course. Though vastly overmatched in terms of raw power, the clever Monkey King used his wits and agility to outwit the demon at every turn.Again and again, the White Bone Demon tried to blast Wukong with her foul energy beams, only for the nimble primate to dodge and somersault out of harm's way. Each time she thought she had him cornered, Wukong would pull off an astonishing escape, driving the demon into a frothing rage."You miserable monkey! How dare you make a mockery of me?" the White Bone Demon howled. "I will grind your bones into dust!"But Wukong remained defiant, his courage unwavering in the face of such bigotry. "It is you who are the fool, judging me solely on my appearance!" he retorted. "My spirit is as immense as the cosmos itself!"After hours of intense combat, Wukong finally landed a decisive blow, using his legendary staff to shatter the demon's defenses. As the White Bone Demon lay defeated and broken, Wukong stood over her, a look of pity on his face."This is the price of hatred and prejudice," he said solemnly. "I hope you have learned that true strength comes from within, not from how one looks on the outside."With that, the Monkey King turned and walked away, leaving the fallen demon to reflect on the wage of her racist ways. From that day forward, Wukong's legend spread far and wide as a symbol of perseverance in the face of discrimination.No matter our shape, size or species, the tale of the Monkey King reminds us to embrace our diversity and judge others notby their appearance, but by their character. For in the end, we all bleed the same color.。
人工添加酵母硒对吉富罗非鱼肌肉蛋白、脂肪及氨基酸的影响
51卷收稿日期：2020-01-06基金项目：国家自然科学基金项目（31960733）；广西自然科学基金项目（2018GXNSFAA138128）；国家现代农业产业技术体系建设专项（CARS-46）作者简介：*为通讯作者，罗永巨（1968-），博士，研究员，主要从事罗非鱼种苗繁殖及其营养学研究工作，E-mail ：lfylzc123@ 。
李柳清（1992-），研究方向为水产动物营养与饲料学，E-mail ：****************人工添加酵母硒对吉富罗非鱼肌肉蛋白、脂肪及氨基酸的影响李柳清1，2，3，4，罗永巨1，2，3，4*，肖俊2，黄一帆5，阴晴朗1，2，3，4，王志芳2，檀午芳1，2，3，4（1水产科学国家级实验教学示范中心（上海海洋大学），上海201306；2广西水产科学研究院/广西水产遗传育种与健康养殖重点实验室，南宁530021；3农业农村部鱼类营养与环境生态研究中心（上海海洋大学），上海201306；4农业农村部淡水水产种质资源重点实验室（上海海洋大学），上海201306；5广西分析测试中心，南宁530022）摘要：【目的】明确在日粮中人工添加酵母硒对吉富罗非鱼肌肉营养成分的影响，为开发生产优质的富硒吉富罗非鱼产品提供科学依据。
【方法】以含不同浓度［0（对照）、3、5和10mg/kg ］酵母硒的日粮投喂吉富罗非鱼，日投喂量为鱼体重的2.5%~3.0%，连续投喂28d 后统一投喂普通饲料7d 。
于饲养第35d 采集吉富罗非鱼背部肌肉，从肌肉蛋白、氨基酸及硒含量等角度对比分析酵母硒对吉富罗非鱼肌肉营养成分的影响，并采用国际通用的营养评价方法评估其营养价值。
【结果】日粮中添加酵母硒可提高吉富罗非鱼肌肉粗蛋白含量及降低粗脂肪含量。
4组吉富罗非鱼肌肉中均检测出17种氨基酸，含量最高的是谷氨酸（Glu ），其次是天冬氨酸（Asp ）、赖氨酸（Lys ）和亮氨酸（Leu ），含量最低的是半胱氨酸（Cys ）；均以鲜味氨基酸和甜味氨基酸为主，且各酵母硒处理组吉富罗非鱼高于对照组吉富罗非鱼。
基于碳氮稳定同位素技术的西北太平洋富山武装乌贼和相拟钩腕乌贼生态位变化研究
第38卷第3期大连海洋大学学报Vol.38No.3 2023年6月JOURNAL OF DALIAN OCEAN UNIVERSITY June2023DOI:10.16535/ki.dlhyxb.2022-250文章编号:2095-1388(2023)03-0515-09基于碳氮稳定同位素技术的西北太平洋富山武装乌贼和相拟钩腕乌贼生态位变化研究张嘉琦1,刘必林1,2,3,4∗(1.上海海洋大学海洋科学学院,上海201306;2.国家远洋渔业工程技术研究中心,上海201306;3.大洋渔业资源可持续开发教育部重点实验室,上海201306;4.农业农村部大洋渔业可持续利用重点实验室,上海201306)摘要:为深入了解大洋性小型头足类在海洋食物网中的作用,根据2019年 淞航 号渔业资源调查船所采集的样本,采用碳氮稳定同位素(δ13C㊁δ15N)技术对西北太平洋富山武装乌贼(Enoploteuthis chunii)和相拟钩腕乌贼(Abralia similis)两种小型头足类的生态位变化进行了研究㊂结果表明:各站点间富山武装乌贼的δ13C㊁δ15N和δ15N b值具有显著性差异(P<0.05),相拟钩腕乌贼的δ13C和δ15N b值具有显著性差异(P<0.05),而δ15N值无显著性差异(P>0.05);个体发育过程中,富山武装乌贼的δ13C和δ15N值与胴长无显著相关性(P>0.05),δ15N b值与胴长显著相关(P<0.05),而相拟钩腕乌贼的δ13C㊁δ15N和δ15N b值与胴长无显著相关性(P>0.05);富山武装乌贼成鱼期的营养生态位宽度较大(SEAc=1.78ɢ2)且与稚鱼期的重叠度较低(0.19),相拟钩腕乌贼稚鱼期(SEAc=0.68ɢ2)与成鱼期的营养生态位宽度(SEAc=0.39ɢ2)变化较小,两者之间重叠度中等(0.37),稚鱼期两种乌贼种间营养生态位重叠度中等(0.33),而成鱼期种间重叠度较低(0.20)㊂研究表明,富山武装乌贼的δ13C㊁δ15N值主要受同位素基线值空间变化及摄食作用的影响,而相拟钩腕乌贼的δ13C㊁δ15N值则更多受同位素基线值空间变化的影响㊂关键词:富山武装乌贼;相拟钩腕乌贼;稳定同位素;摄食生态中图分类号:S931.5㊀㊀㊀㊀文献标志码:A㊀㊀富山武装乌贼(Enoploteuthis chunii)和相拟钩腕乌贼(Abralia similis)均为外海小型头足类,隶属于鞘亚纲(Coleoidea)枪形目(Teuthoidea)武装乌贼科(Enoploteuthidae)㊂富山武装乌贼主要分布于日本大陆架及临近水域,包括中国东海及黑潮-亲潮过渡区域直至夏威夷海域,其最大胴长约为100mm㊂相拟钩腕乌贼分布于热带西太平洋㊁太平洋赤道至亚热带海域,包括巴布亚新几内亚㊁汤加南部海域,最大胴长约为35mm[1-2]㊂国内外对富山武装乌贼和相拟钩腕乌贼的相关研究较少,仅限于对两个物种的空间分布和生物学特征方面的研究[3]㊂Watanabe等[4]指出,与多数头足类相似,大部分海域的富山武装乌贼存在昼夜垂直洄游运动,而在海洋暖涡(warm core ring,WCR)附近的富山武装乌贼始终栖息于400m水深以下㊂此外,两种头足类作为饵料生物,多被海洋哺乳动物及鱼类所摄食,包括侏儒抹香鲸(Kogia sima)[5]和太平洋蓝鳍金枪鱼(Thunnus orientalis)[6]等㊂营养生态位对于研究物种的种间关系㊁资源相互利用,以及了解生态系统中的群落结构和功能发挥着重要作用,其主要反映物种自身的营养需求及其在生态系统中的营养功能[7]㊂目前,稳定同位素技术已经广泛运用于水生生物的营养生态位分析,相较于胃含物分析的短期性及偶然性,稳定同位素作为天然示踪剂提供了生态系统中物质来源和输送过程等重要信息,并用于研究生物的能量来源㊁食性变化及营养关系的时空变化[8]㊂其中,生物个体组织中的碳氮稳定同位素(δ13C㊁δ15N)可以反映生物个体摄食及栖息地的长期变化情况[9]㊂由于δ13C值在各营养级富集较低,仅为0~ 1ɢ,因此,δ15C可用于指示初级生产力的来源,并用于区分生物个体摄食区域的水平和垂直变化,㊀收稿日期:2022-08-20㊀基金项目:农业农村部全球渔业资源调查监测评估(公海渔业资源综合科学调查)专项;上海市高校特聘教授 东方学者 岗位跟踪计划项目(GZ2022011)㊀作者简介:张嘉琦(1998 ),女,硕士研究生㊂E-mail:qiqi_yaa@㊀通信作者:刘必林(1980 ),男,博士,教授㊂E-mail:bl-liu@如近岸与离岸㊁中上层与底栖及较低纬度与较高纬度之间的浮游生物量变化[10]㊂而δ15N在各营养级间的富集程度较高(2ɢ~3.5ɢ),并沿着食物链逐步富集,将营养传递至更高营养级,因此,δ15N 多用于确定研究对象的营养位置,也可用于指示个体在其生命周期内的摄食营养差异变化[11]㊂生物个体不同组织的不同周转速率及分馏系数,也反映了个体在不同时间尺度上的摄食情况变化㊂硬组织(如眼睛晶体㊁角质颚及内壳等)因其具有周期性的生长增量,故可用于分析头足类生活史过程[12]㊂Liu等[13]采用眼睛晶体稳定同位素,对秘鲁外海的茎柔鱼不同生长期的摄食策略和地理迁移运动研究发现,茎柔鱼在生活史早期阶段摄食区域范围较大,而进入成鱼期后其主要在同一栖息地摄食,并存在摄食选择偏向性,同时在胚胎期与成鱼期之间茎柔鱼也具有不同的营养分布和空间生态㊂与硬组织相比,肌肉的稳定同位素值可以反映生物体一段时间内的摄食信息,一般为几个月至一年左右;肝脏的稳定同位素值等可以提供几周内的摄食信息;性腺和消化腺的稳定同位素周转率则更快,通常可以反映几天内的摄食信息[14]㊂操亮亮等[15]通过肌肉组织稳定同位素值,对东南太平洋厄瓜多尔和秘鲁公海茎柔鱼的生长过程中摄食生态及地理差异变化研究发现,厄瓜多尔和秘鲁公海的茎柔鱼生态位间存在差异,其中,秘鲁公海的茎柔鱼δ13C和δ15N值变化主要受到摄食变化的影响,而厄瓜多尔的茎柔鱼则受到同位素基线值变化及摄食变化的共同影响㊂目前,有关富山武装乌贼和相拟钩腕乌贼的营养生态位研究国内外均处于空白,而两种乌贼作为饵料生物被西北太平洋众多捕食者所摄食,在生态系统中也发挥着重要作用㊂本研究中,通过肌肉碳氮稳定同位素分析,研究了西北太平洋两种小型头足类 富山武装乌贼和相拟钩腕乌贼个体发育期及种间营养生态位变化,以期为深入了解大洋性小型头足类摄食生态及种间生态关系提供基础资料㊂1㊀材料与方法1.1㊀样本来源渔业生物样品及浮游动物样品均由上海海洋大学渔业资源调查船 淞航 号于2019年3月21 23日和9月5 8日在西北太平洋黑潮-亲潮区域调查期间采集(146ʎ30ᶄ~150ʎ13ᶄE,31ʎ00ᶄ~39ʎ00ᶄN)㊂调查共采集富山武装乌贼51尾,相拟钩腕乌贼30尾,分类清洗后置于-20ħ下冻存㊂各站点附近使用大型浮游生物网(网长为2.8m,网口内径为80cm,筛绢孔径约为0.505mm)由200m水深垂直拖至表层,拖速为0.5~0.8m/s㊂网采样品使用海水冲洗并经149μm筛绢过滤后于-20ħ下冻存(图1㊁表1)㊂本图基于自然资源部标准地图服务网站GS(2020)4392号标准地图为底图,底图边界无修改㊂The figure is based on the standard map GS(2020)4392in the Standard Map Service website of Ministry of Natural Resources of the People s Republic of China,with no modifications of the boundaries in the standard map.图1㊀西北太平洋富山武装乌贼㊁相拟钩腕乌贼采集站点及黑潮-亲潮过渡区[19]分布Fig.1㊀Sampling sites of Enoploteuthis chunii and Abralia similis and the distribution Kuroshio-OyashioTransition Zone[19]in the Northwest PacificOcean1.2㊀方法1.2.1㊀样本预处理㊀在显微镜下挑出桡足类样品并置于15mL离心管中,使用Milli-Q超纯水进行反复冲洗和离心(6000r/min,离心3min),将最终沉积的桡足类置于1.5mL离心管中,在烘箱(60ħ)中烘干至恒质量,并使用MM400混合型球磨仪研磨成均匀粉末,称取1.5mg粉末置于锡舟中包样待测㊂头足类样品在实验室常温静置解冻后,清洗并测定生物学数据,包括胴长(mm)㊁体质量(g)等,其中,长度测量精确到1mm,质量测量精确615大连海洋大学学报㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第38卷表1㊀渔业生物采样站点信息Tab.1㊀Sampling sites information of fishery organisms种类species 采样日期samplingdate站点编号siteNo.经纬度coordinates样本数/ind.number富山武装乌贼(E.chunii)2019-03-21S1148ʎ00ᶄE,33ʎ00ᶄN16 2019-03-23S2148ʎ00ᶄE,31ʎ59ᶄN3 2019-09-05S3148ʎ05ᶄE,38ʎ45ᶄN32相拟钩腕乌贼(A.similis)2019-03-23S2148ʎ00ᶄE,31ʎ59ᶄN3 2019-09-05S3148ʎ05ᶄE,38ʎ45ᶄN23 2019-09-08S4150ʎ13ᶄE,35ʎ56ᶄN3 2019-09-09S5148ʎ02ᶄE,34ʎ43ᶄN1到0.01g㊂在各样品的胴体腹部剪取适量肌肉,所有肌肉样品去除表皮后,使用Milli-Q超纯水冲洗5min,以去除可能的污染物质,在冷冻干燥机内进行冷冻干燥(-50ħ,干燥30h)㊂与桡足类相同,干燥后使用球磨仪研磨成均匀粉末,称取1.5mg粉末放入锡舟中包样待测㊂1.2.2㊀稳定同位素分析㊀使用ISOPRIME100稳定同位素质谱仪(Isoprime Corporation,Cheadle, UK)及VarioISOTOPE Cube元素分析仪(Elemen-tar Analysensysteme GmbH,Hanau,Germany)进行碳氮稳定同位素测定㊂计算公式为δX=(R sample-R standard)/R standardˑ103㊂式中:δ值为国际通用的稳定同位素比值;X为13C 或15N;R sample和R standard分别为样品和标准物中的13C/12C或15N/14N值㊂在测定过程中,采用美洲拟箭石(PDB)和纯化大气氮(N2)作为碳氮稳定同位素的标准物质㊂同时,为保证测样结果的稳定性,每10个测试样品后插入3个标准同位素样品,分析精度为ʃ0.06ɢ㊂由于头足类肌肉中含有丰富的脂类,在测定过程中会导致δ13C值存在偏差[16]㊂在进行碳氮稳定同位素分析时,当CʒN< 3.5时,则不需要进行脂类去除处理[17];当CʒN>3.5时,本研究中选用已有的北太平洋柔鱼脂类校正模型样品的δ13C值进行修正[18]㊂1.2.3㊀δ15N基线值调整㊀为了准确比较种间的摄食营养水平差异变化,根据各站点附近所采集的桡足类δ15N值作为基线值,通过减去基线值来调整所有样本的δ15N值,调整后的δ15N值称为δ15N b值㊂1.2.4㊀生态位宽度和重叠率的计算㊀根据卜心宇等[19]和Guerra-Marrero等[20]的研究,富山武装乌贼胴长小于31mm为稚鱼期,胴长大于32mm 为成鱼期;相拟钩腕乌贼胴长小于20mm为稚鱼期,胴长大于21mm为成鱼期㊂基于样本的δ13C和δ15N值在R4.2.0软件中使用SIBER包绘制富山武装乌贼和相拟钩腕乌贼不同生长时期营养生态位,计算贝叶斯标准椭圆面积(SEAc),采用SIAR包计算营养生态位重叠率,并根据Layman等[21]的判定方法判断富山武装乌贼和相拟钩腕乌贼个体发育期内及种间不同时期营养生态位的重叠率㊂采用非参数估计的局部加权回归散点平滑法(LOESS)对富山武装乌贼和相拟钩腕乌贼的δ13C㊁δ15N和δ15N b与胴长的关系分别进行拟合㊂此外,考虑到S5站点仅获取1尾相拟钩腕乌贼,因此,S5站点样本数据未用作有关碳氮稳定同位素值的地理差异分析㊂1.3㊀数据处理本研究中,试验数据均以平均值ʃ标准差(meanʃS.D.)表示,并采用单因素方差分析法(one-ANOVA)对两个物种间㊁种内不同站点间的δ13C和δ15N差异进行显著性分析,采用SPSS26.0软件进行统计检验,显著性水平α=0.05㊂2㊀结果与分析2.1㊀胴长组成从图2可见:富山武装乌贼胴长为11~ 62mm,优势胴长为26~35mm;相拟钩腕乌贼胴长为13~36mm,优势胴长为16~25mm㊂两个物种的胴长具有显著性差异(F=73.915,P<0.05)㊂不同采样站点间,富山武装乌贼的胴长有显著性差异(F=40.273,P<0.05),而相拟钩腕乌贼的胴长无显著性差异(F=1.648,P>0.05)㊂图2㊀富山武装乌贼和相拟钩腕乌贼胴长分布Fig.2㊀Mantle length distribution of Enoploteuthis chu-nii and Abralia similis2.2㊀稳定同位素值富山武装乌贼δ13C值为-20.53ɢ~-18.27ɢ,δ15N值为8.67ɢ~12.17ɢ;相拟钩腕乌贼δ13C值为-19.60ɢ~-18.73ɢ,δ15N值为8.21ɢ~ 11.12ɢ㊂两个物种的δ13C值无显著性差异(F=715第3期张嘉琦,等:基于碳氮稳定同位素技术的西北太平洋富山武装乌贼和相拟钩腕乌贼生态位变化研究1.104,P >0.05),δ15N 值有显著性差异(F =73.090,P <0.05)㊂基线调整后的富山武装乌贼和相拟钩腕乌贼δ15N b 值分别为2.82ɢ~7.26ɢ和1.62ɢ~8.21ɢ,且两个物种的δ15N b 值有显著性差异(F =13.461,P <0.05)㊂S2站点中,两个物种的δ13C㊁δ15N 和δ15N b值均无显著性差异(F C =0.574,P C >0.05;F N =0.000,P N >0.05;F Nb =0.001,P Nb >0.05);S3站点中,两个物种的δ15N 和δ15N b 值均有显著性差异(F N =13.813,P N <0.05;F N b =13.800,P N b <0.05),而δ13C 值无显著性差异(F =3.643,P >0.05);富山武装乌贼在S3站点具有较大的δ13C㊁δ15N 值,而相拟钩腕乌贼在S3站点具有较大的δ15N 值,在S4站点具有较大的δ13C 值(表2)㊂从整体上看,站点对富山武装乌贼δ13C㊁δ15N 和δ15N b 值均有显著性影响(F C =5.021,P C <0.05;F N =9.868,P N <0.05;F N b =9.715,P N b <0.05),除了δ13C 值中S1与S2站点及S2与S3站点,δ15N 值中S1与S3站点外,其余各站点间δ13C㊁δ15N b 和δ15N b 值均存在显著性差异(P <0.05)㊂站点对相拟钩腕乌贼δ13C 和δ15N b 值有显著性影响(F C =6.988,P C <0.05;F N b =39.490,P N b <0.05),而对δ15N 值无显著性影响(F =2.473,P N >0.05)(表2)㊂表2㊀渔业生物样本信息Tab.2㊀Specimen information of fishery organisms种类species 站点site 胴长/mm mantle lengthδ13C /ɢδ15N /ɢ基线δ15Nbaseline δ15N /ɢδ15N b /ɢ富山武装乌贼(E .chunii )S146.75ʃ8.85a -19.60ʃ0.72b10.11ʃ0.97a 4.51 5.60ʃ0.97b S219.67ʃ3.21b -19.39ʃ0.19ab 9.32ʃ0.23b2.39 6.92ʃ0.23a S328.69ʃ6.37b -19.07ʃ0.12a 10.70ʃ0.59a 6.52 4.18ʃ0.59c 相拟钩腕乌贼(A .similis )S220.33ʃ1.53a -19.49ʃ1.20c 9.33ʃ1.20a 2.39 6.93ʃ1.20aS322.78ʃ5.08a -19.15ʃ0.20b10.13ʃ0.50a 6.52 3.61ʃ0.50b S417.67ʃ3.51a-18.83ʃ0.08a9.62ʃ0.44a7.59 2.03ʃ0.44cS528-19.389.46 5.833.63㊀注:同列中标有不同字母者表示同一物种不同站点间有显著性差异(P <0.05),标有相同字母者表示站点间无显著性差异(P >0.05)㊂Note:means with different letters within the same column in same species are significantly different in different site at the 0.05probability level,and the means with the same letter within the same column are not significant differences.2.3㊀稳定同位素值与胴长的关系在个体生长发育过程中,富山武装乌贼的δ13C㊁δ15N 值与胴长无显著相关性(F C =1.283,P C >0.05;F N =0.243,P N >0.05),δ15N b 值随胴长的增大而显著增大(F =11.218,P <0.05);相拟钩腕乌贼的δ13C㊁δ15N 和δ15N b 值随胴长的变化均无显著相关性(F C =1.442,P C >0.05;F N =0.179,P N >0.05;F N b =0.005,P N b >0.05)㊂此外,按图2所划分的胴长组,并计算各胴长组平均胴长,分析富山武装乌贼和相拟钩腕乌贼各胴长组内δ13C㊁δ15N 值变化,结果显示,富山武装乌贼和相拟钩腕乌贼的δ13C㊁δ15N 和δ15N b 值在同一胴长组内均出现较大的波动(图3)㊂2.4㊀个体发育期营养生态位对比从表3可见:稚鱼期,富山武装乌贼与相拟钩腕乌贼的胴长有显著性差异(F =33.688,P <0.05),而δ13C㊁δ15N 和δ15N b 值均无显著性差异(F C =0.108,P C >0.05;F N =1.736,P N >0.05;F N b =0.134,P N b >0.05);成鱼期,两个物种的胴长㊁δ15N 和δ15N b 值均有显著性差异(F ML =32.049,P <0.05;F N =34.352,P N <0.05;F Nb =33.443,P Nb <0.05),而δ13C 值无显著性差异(F =2.846,P >0.05)㊂不同生长时期营养生态位分析显示:富山武装乌贼成鱼期营养生态位宽度(SEAc =1.78ɢ2)大于稚鱼期(SEAc =0.32ɢ2),两者间重叠率较低(0.19);相拟钩腕乌贼成鱼期的营养生态位宽度(SEAc =0.39ɢ2)小于稚鱼期(SEAc =0.68ɢ2),两者间重叠率中等(0.37)(图4)㊂种间分析显示,富山武装乌贼与相拟钩腕乌贼稚鱼期的重叠率中等(0.33),成鱼期重叠率较低(0.20)(图5)㊂3㊀讨论3.1㊀碳氮稳定同位素值的地理差异生物组织中的δ13C 值反映了初级生产力的来源,并随纬度和海岸水平距离产生变化㊂本研究中,富山武装乌贼和相拟钩腕乌贼不同站点δ13C 值815大连海洋大学学报㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第38卷图3㊀富山武装乌贼和相拟钩腕乌贼各胴长组的δ13C㊁δ15N㊁δ15N b值及其与胴长的平滑拟合Fig.3㊀Relationship betweenδ13C,δ15N andδ15N b values with each mantle length group and smooth fitting with mantle length of Enoploteuthis chunii and Abralia similis表3㊀两种头足类不同发育时期的生物信息Tab.3㊀Biological information at the different ontogenies of two cephalopods种类species生长时期ontogenies胴长mantle length(范围range)/mmδ13C(范围range)/ɢδ15N(范围range)/ɢδ15N b(范围range)/ɢ富山武装乌贼(E.chunii)稚鱼期juvenile25.61ʃ5.03b(11~33)-19.11ʃ0.16a(-19.61~-18.85)10.45ʃ0.67a(9.06~11.85)4.37ʃ1.05b(2.82~7.08)成鱼期adult43.83ʃ8.79a(32~62)-19.43ʃ0.65b(-20.53~-18.27)10.40ʃ0.96a(8.67~12.17)5.28ʃ0.98a(4.05~7.26)相拟钩腕乌贼(A.similis)稚鱼期juvenile17.40ʃ2.27c(13~20)-19.13ʃ0.24a(-19.53~-18.73)10.11ʃ0.82ab(8.21~11.12)4.20ʃ1.80bc(1.62~8.21)成鱼期adult24.60ʃ4.10b(21~36)-19.17ʃ0.24ab(-19.60~-18.73)9.92ʃ0.51b(9.17~11.03)3.58ʃ0.94c(1.98~6.78)注:同列中标有不同字母者表示组间有显著性差异(P<0.05),标有相同字母者表示组间无显著性差异(P>0.05)㊂Note:The means with different letters within the same column are significantly different in the groups at the0.05probability level,and the means with thesame letter within the same column are not significant differences.的显著变化差异可能与地理变化差异有关㊂位于黑潮以北及黑潮-亲潮过渡区的S3和S4站点中,富山武装乌贼和相拟钩腕乌贼均有较高的δ13C值㊂Nishikawa等[22]研究发现,黑潮㊁亲潮交汇带来了丰富的营养物质,为小型中上层鱼类提供了重要的索饵育肥场㊂Rau等[23]指出,随着海表面温度(SST)的升高,浮游植物的δ13C值随之增大㊂此外,水中的CO2浓度及浮游植物的生长速度也会影响其碳同位素的分馏作用[24]㊂这些影响因素会对浮游植物的δ13C值产生影响,并最终反映在鱿鱼的δ13C值中[25]㊂本研究中,S3和S4采样站点的SST(分别为25.20㊁28.70ħ)高于S1和S2站点(分别为18.04㊁17.91ħ)(https://resources. marine.copernicus.eu/products),因此,SST较高的站点有丰富的营养物质,使得营养盐㊁浮游植物等较大的初级生产力随着食物网中物质㊁能量流动,最终反映在富山武装乌贼和相拟钩腕乌贼的肌肉δ13C值中㊂915第3期张嘉琦,等:基于碳氮稳定同位素技术的西北太平洋富山武装乌贼和相拟钩腕乌贼生态位变化研究图4㊀富山武装乌贼和相拟钩腕乌贼不同生长时期营养生态位Fig.4㊀Trophic niche of Enoploteuthis chunii and Abralia similis at differentstages图5㊀不同生长时期富山武装乌贼和相拟钩腕乌贼营养生态位对比Fig.5㊀Comparison of the trophic niche between Enoploteuthis chunii and Abralia similis at ontogenetic stages㊀㊀与不同采样站点的δ13C 值存在显著性差异的原因不同,富山武装乌贼不同采样站点的δ15N 值的显著性差异可能受基线值的空间变化和营养效应两方面影响[26]㊂本研究中,使用采样站点附近的浮游动物桡足类δ15N 值作为基线,对δ15N 值进行基线调整后,各采样站点的δ15N b 值也具有显著性差异,同时,富山武装乌贼各采样站点的胴长也存在显著性差异㊂因此,笔者认为,各站点物种胴长差异所带来的摄食结构变化,会造成各站点乌贼肌肉中δ15N 值的空间差异㊂同时大多数头足类均会出现明显的洄游行为,在其生命周期中将跨越多个不同的栖息地环境[27]㊂Young 等[28]指出,如果研究对象是在被捕捞前的短时间内迁移至采样站点,使用采样站点基线对组织δ15N 值进行调整会产生一定的空间偏差,同时肌肉组织中也整合了生物个体一段时间内的摄食信息㊂因此,富山武装乌贼的洄游迁移运动对各采样站点的δ15N 值的空间差异也产生一定程度的影响㊂而相拟钩腕乌贼各采样站点的δ13C㊁δ15N b 值差异显著及胴长差异不显著,表明各站点间的同位素值差异更多的来自基线值的空间变化㊂3.2㊀个体发育对稳定同位素值变化的影响头足类的个体发育往往会带来其摄食习性及摄食范围等的变化,并反映在其稳定同位素值的变化中㊂本研究中,与富山武装乌贼胴长小于31mm组相比,胴长为31~48mm 时,胴长组内δ13C 值变化较大,同时,δ15N b 值随胴长的增大而显著增加(图3)㊂出现这种情况的原因可能有两个方面:一是,随着富山武装乌贼的个体的生长,其游泳能力逐渐增强,可以在更大的区域范围内进行摄食;二是,角质颚的不断生长及个体体型的增大,也使其在摄食猎物的选择上,从最初仔鱼期的小型浮游动物这类营养水平较低的生物开始向大型浮游动物㊁甲壳类和小型鱼类等营养水平较高及体型更大的生物进行转变[19],这种摄食变化现象也在头足类个体发育过程中被广泛观察到,如茎柔鱼[29]㊂此外,头足类是贪婪的机会主义摄食者[30],同一个胴长组内由于摄食区域的差异,有着不同营养水平的食物资源,从而使同一胴长组内δ15N b 值产生较大的变化㊂本研究中,所采集的富山武装乌贼中胴长较大(ML>48mm)的个体主要集中于S1站25大连海洋大学学报㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第38卷点,摄食范围集中;随着个体发育逐渐趋于成熟,富山武装乌贼的摄食习性逐渐倾向于更高营养水平的生物,其摄食种类也更趋向于稳定,因此,在富山武装乌贼生命后期,同一胴长组的δ13C和δ15N b 值变化范围逐渐降低㊂本研究中,相拟钩腕乌贼个体发育过程中,δ15N和δ15N b值随胴长的变化较小,这可能是由于在相拟钩腕乌贼整个生长过程中,摄食的主要对象为浮游动物,这种摄食习性也在其他小型头足类如魏氏钩腕乌贼和小钩腕乌贼的摄食中被观察到[20]㊂当胴长小于25mm时,相拟钩腕乌贼δ13C值变化范围较大,同时随着个体发育,δ15N和δ15N b值呈现下降趋势(图3)㊂Somes等[31]研究认为,如果排除个体发育过程中营养变化的影响,在鱿鱼生长过程中,δ15N值会出现系统性下降,这一过程往往与迁移运动中的栖息地变化所带来的基线生物δ15N值的降低有关㊂而Takai等[27]研究则发现,与δ13C值变化相似,浮游植物的δ15N值具有纬度方向上的变化,随纬度的增加而降低㊂本研究中,相拟钩腕乌贼各站点间同位素值的微小差异更多来自基线值的差异,且胴长小于25mm的相拟钩腕乌贼在S2㊁S3和S4站点均有分布,而胴长大于25mm的乌贼则主要分布在S3站点㊂由此可见,当相拟钩腕乌贼处于仔稚鱼期及未成熟的幼鱼期时,会逐渐向黑潮-亲潮过渡区洄游,然后随着个体的发育生长及黑潮-亲潮过渡区所提供的丰富的饵料生物,相拟钩腕乌贼也会开始摄食体型更大㊁能量更高的猎物以满足性腺发育的营养需求[32],因此,当胴长大于25mm后,其δ15N和δ15N b值均出现连续增长趋势,而δ13C值变化则较小㊂3.3㊀不同生长时期生态位的变化营养生态位宽度主要反映了生物摄食资源的多样性和均匀度[33],而生态位的重叠反映了物种间资源利用的相似度和竞争关系[34]㊂本研究中,富山武装乌贼在个体发育过程中,稚鱼期时体型较小,游泳能力较弱,主要摄食浮游动物,摄食资源较为单一,活动范围较小,因此,生态位宽度较小;成鱼期的富山武装乌贼随着胴长的增大,游泳能力加强,具有明显的昼夜垂直洄游习性,且昼夜分离明显,对生态系统中的能量物质输送起着重要作用[35],同时富山武装乌贼垂直和水平活动范围增大,摄食营养水平增加,从而有着更大的生态位宽度㊂此外,富山武装乌贼稚鱼期和成鱼期营养生态位间较低的重叠率,也反映了物种个体发育过程中存在较为明显的摄食习性变化及栖息地利用范围的增大㊂相拟钩腕乌贼在个体发育过程中,稚鱼期营养生态位宽度略大于成鱼期,且重叠率中等㊂相拟钩腕乌贼在整个生命周期中主要摄食浮游动物,成鱼期主要集中在黑潮-亲潮过渡区进行索饵,并随着胴长的增大及个体发育中能量的需求,其摄食开始出现一定偏向性,并开始摄食一些体型较大㊁能量更高的猎物,从而会出现稚鱼期和成鱼期营养生态位宽度较小的变化及中等程度的重叠率㊂两个物种间对比发现,稚鱼期富山武装乌贼与相拟钩腕乌贼营养生态位宽度相比差异较小,且δ13C和δ15N值均无显著性差异,由于在该时期两个物种胴长较小,主要摄食浮游动物,笔者认为造成营养生态位的微小差异可能与采样站点的分布有关㊂本研究中,所采集的稚鱼期富山武装乌贼站点为S2㊁S3,稚鱼期相拟钩腕乌贼站点为S2㊁S3和S4㊂因此,稚鱼期相拟钩腕乌贼站点分布较广可能是造成其营养生态位较宽的主要原因,同时中等程度的重叠率也进一步证明了两个物种在稚鱼期栖息地存在一定的差异㊂而成鱼期,两个物种的δ15N 和δ15N b值具有显著性差异,这是因为富山武装乌贼有着较大的胴长㊁较强的游泳能力及明显的摄食习性的改变,因此,有着更大的生态位宽度,且两者之间的重叠率较低㊂4㊀结论1)富山武装乌贼δ13C㊁δ15N值主要受到同位素基线值空间变化及摄食作用的影响,而相拟钩腕乌贼δ13C㊁δ15N值主要受到同位素基线值空间变化的影响㊂2)整个生命周期中,富山武装乌贼和相拟钩腕乌贼主要以黑潮-亲潮过渡区作为索饵育肥场所㊂3)个体发育过程中,富山武装乌贼随胴长的增大出现摄食习性变化,成鱼期营养生态位宽度较大,有着更大的运动范围及摄食资源多样性;相拟钩腕乌贼主要摄食浮游动物,其稚鱼期与成鱼期之间营养生态位宽度变化较小,随胴长的增大及个体发育能量的需求,该乌贼在成鱼期摄食也会出现一定的偏向性,开始摄食一些营养水平更高的猎物㊂参考文献:[1]㊀OKUTANI T K.Abralia similis,a new enoploteuthid squid from thenorthwest Pacific(Cephalopoda,Oegopsida)[J].Bulletin of the National Science Museum Series A,Zoology,1987,13(4):141-150.125第3期张嘉琦,等:基于碳氮稳定同位素技术的西北太平洋富山武装乌贼和相拟钩腕乌贼生态位变化研究。
柴达木野生黑果枸杞的空间遗传结构
植物生态学报 2020, 44 (6): 661–668 DOI: 10.17521/cjpe.2019.0298 Chinese Journal of Plant Ecology 柴达木野生黑果枸杞的空间遗传结构王春成1马松梅1,2*张丹1王绍明11绿洲城镇与山盆系统生态兵团重点实验室, 石河子大学生命科学学院, 新疆石河子 832000; 2绿洲城镇与山盆系统生态兵团重点实验室, 石河子大学理学院, 新疆石河子 832000摘要基于cpDNA序列, 研究柴达木野生黑果枸杞(Lycium ruthenicum)的遗传多样性、遗传结构和单倍型进化关系, 可为其种群的遗传保护提供理论依据。
该研究基于3个筛选的叶绿体多态引物: psb A-trn H、psb K-psb I和trn V, 利用群体遗传分析方法研究柴达木盆地野生黑果枸杞的遗传变异格局: 利用软件DnaSP 6.0和Permut 2.0计算分子多样性指标, 利用分子方差分析研究组间和种群间的遗传变异来源, 利用单倍型网络分析和主坐标分析研究单倍型的聚类关系; 利用最大似然树和贝叶斯系统树分析单倍型的谱系进化关系。
结果显示: 叶绿体序列psb A-trn H、psb K-psb I和trn V拼接后的总长度为1 454 bp, 鉴别出14个核苷酸变异位点, 共定义了7个单倍型。
种群间总的遗传多样(h T)和种群内遗传多样性(h S)分别为0.916和0.512。
AMOVA分析结果表明, 80%以上的遗传变异来源于组间和种群间。
叶绿体单倍型的贝叶斯系统树和最大似然树均表明柴达木盆地黑果枸杞种群聚为2支: 德令哈和格尔木为一支, 诺木洪为另一支。
单倍型网络和主坐标分析结果揭示的拓扑结构和聚类关系与系统树一致。
Mantel检验结果表明柴达木黑果枸杞种群间的遗传距离与地理距离存在显著的弱相关关系(r = 0.591 1, p = 0.000 9)。
微生物遗传多样性的挖掘和代谢工程应用
微生物遗传多样性的挖掘和代谢工程应用赵心清;陈洪奇;许建韧【摘要】With the in-depth studies of systems bology,multi-omics( genomics,transcriptomics,proteomicsand metabolomics)data is increasingly emerging. It has been well studied and accepted that there is a vast diversity of mi-croorganisms in China,however,so far most studies focus on the species diversity and its ecological implication,there is still few studies focusing on the genetic diversity of microorganisms. In this review,brewing yeast strains of Saccha-romyces cerevisiae and streptomycetes were used as examples,and research progress in the exploration of the genetic diversity of genes responsible for yeast flocculation and stress tolerance,as well as special promoter sequence in indus-trial yeast strains was summarized. In addition,the effect of regulatory protein identified from marine actinobacteria on heterologous antibiotic production was also presented. Exploration and utilization of the genetic diversity of microorgan-isms provides basis for not only the understanding of specific regulatory mode in different strains of microorganisms, but also the metabolic engineering of microorganisms using diverse genetic elements.%随着近年来系统生物学研究的深入，微生物的基因组、转录组、蛋白组及代谢组等不同层次的组学信息不断增加。
八角莲的遗传多样性研究
八角莲的遗传多样性研究Studies on genetic diversity inZhou Xin-Wen Fu Cheng-Xin周新闻傅承新（浙江大学生命科学学院生物系,系统与进化植物学实验室，杭州310029）摘要本研究从保护生物学的角度，对珍稀濒危植物八角莲的遗传多样性进行了研究和分析。
采用淀粉凝胶电泳方法，分析了9个酶系统，分析结果表明，居群的遗传变异处于较低水平，多态性位点比率P=18.52%,等位基因平均数A=1.22，等位酶基因多样度指数Ho=0.02，He=0.067。
固定指数F 为0.58。
总的基因位点变异中，有45.6%的变异来自于居群间，54.4%的变异存在于居群内。
关键词八角莲,等位酶,遗传多样性, 保护生物学国家八角莲（Changium smyrnioides Wolff）隶属小檗科八角莲属。
广布于湖北，湖南，河南，四川，江西，安徽，浙江，广西，云南，贵州各省的山区。
，为我国著名的特产药材之一。
近年来其分布范围和数量正日益减少，已被国家列为三级珍稀濒危保护植物。
在八角莲的细胞学研究方面，张定成等（1991）报道了八角莲的核型公式。
苏应娟等（1994，1992）对八角莲属的4种植物---八角莲，六角莲，小八角莲，乌云伞进行了孢粉学、形态解剖学、过氧化物同工酶研究，推断八角莲在八角莲属内演化水平居中。
更多的研究集中在八角莲的药学（陈毓亨1979；王丽平等1994，1995；姚莉韵等1999；殷梦龙等1989）。
而对八角莲的遗传多样性及保护生物学方面的研究至今仍未见报道。
生物多样性的保护最终是要保护其遗传多样性，因为一个物种的稳定性和进化潜力依赖其遗传多样性，而一个物种的经济和生态价值也依赖其特有的基因组成（王洪新等，1996）。
物种的遗传多样性可以从形态特征、细胞学特征、生理特征、基因位点及DNA序列等不同方面来体现。
本文从基因位点揭示了八角莲遗传多样性，旨在为濒危植物的保护提供理论依据。
样本量对中苎1号群体遗传多样性参数的影响
样本量对中苎1号群体遗传多样性参数的影响谭龙涛;喻春明;陈平;王延周;陈继康;温岚;熊和平【摘要】In order to determine the optimal sample size of ramie group, we randomly selected 100 clumps from Zhong zhu No. 1 which were blooming for pollinating, and from which 10, 20, 30, 40, 50, 60, 70, 80, 90 plants as sample groups were tested to analyze the genetic diversity parameters. The results showed that the parameter values of SSR molecular marker were relatively stable when sample size of the group was more than 50 plants. And as for the SRAP molecular marker, the sample size was more than 60 plants. The results are useful for providing a scientific basis to determine the sample size for analyzing the genetic diversity of ramie group.%为了确定群体的最适抽样量,本试验从中苎1号开放授粉群体中随机选取100蔸,并从中随机抽取10、20、30、40、50、60、70、80,90个个体组成抽样群体,计算其遗传多样性参数,得出SSR标记在样本量50以上时参数值变化不大,而SRAP标记在样本量60以上时结果较为稳定.为苎麻群体遗传多样性的研究中样本量的选择提供了依据.【期刊名称】《中国麻业科学》【年(卷),期】2012(034)004【总页数】5页(P179-183)【关键词】苎麻(Boehmeria nivea L.);遗传多样性参数;样本量【作者】谭龙涛;喻春明;陈平;王延周;陈继康;温岚;熊和平【作者单位】中国农业科学院麻类研究所,湖南长沙 410205;中国农业科学院麻类研究所,湖南长沙 410205;中国农业科学院麻类研究所,湖南长沙 410205;中国农业科学院麻类研究所,湖南长沙 410205;中国农业科学院麻类研究所,湖南长沙410205;中国农业科学院麻类研究所,湖南长沙 410205;中国农业科学院麻类研究所,湖南长沙 410205【正文语种】中文【中图分类】S563.1作物品种纯度的快速、准确鉴定是作物品种资源保存、研究和利用过程中的一个重要环节。
四种基因位点多态性与运动员耐力表型的关联
四种基因位点多态性与运动员耐力表型的关联魏琦;范家成;杜亚雯【期刊名称】《中国组织工程研究》【年(卷),期】2018(022)016【摘要】背景:研究表明至少有155个DNA位点多态性都与精英运动员的运动能力表型例如速度和耐力、肌肉力量等有关.目的:分析辅肌动蛋白3(ACTN3)基因、核呼吸因子2(NRF2)基因、β2肾上腺素能受体(ADRB2)基因及过氧化物酶体增殖受体γ共激活剂(PPARGC1A)基因4个基因位点多态性与赛艇运动员有氧能力表型关联及其相互效应,为探讨基因多态性位点作用于耐力表型的机制提供依据.方法:应用Case-Control实验设计,分析4个基因多态性位点在15名优秀赛艇运动员和50名普通大学新生对照组中的分布特征.运用基因型累加分值分析4个基因位点多态性与赛艇运动员有氧能力表型指标的关联.结果与结论:运动员组的辅肌动蛋白3基因、过氧物酶体受体γ共激活剂基因及核呼吸因子2基因位点耐力表现优势基因位点频率均高于对照组,且核呼吸因子 2 基因位点运动员组与对照组间有显著性差异.3 组不同基因型总分运动员组的最大摄氧量均值之间有显著性差异.因此推论研究中 3 个基因位点多态性可能是预测优秀耐力运动员运动表型的分子标记,作用机制需要进一步验证探讨.%BACKGROUND: Increasing evidence shows that at least 155 genetic polymorphisms are associated with aerobic performance and elite endurance athlete status. OBJECTIVE: To study the association of α-actin 3 (ACTN3) gene, nuclear respiratory factor 2 (NRF2), β2 adrenergic receptor (ADRB2) gene and peroxisome proliferative activated receptor gamma coactivator 1 alpha (PPARGC1A) polymorphic loci with aerobicperformance of rowing athletes and their interaction effect, thereby providing basis for understanding the mechanism of genetic polymorphisms acting on endurance athlete status. METHODS: A case-control experiment was designed to analyze the distribution characteristics of four gene polymorphism loci in 15 excellent rowing athletes and 50 common college freshmen. The association of four polymorphic loci with the aerobic performance-related indexes was analyzed using total genotype scores. RESULTS AND CONCLUSION: The preponderant polymorphism locus distributions of ACTN3, PPARGC1A and NRF2 in the athletes group were higher than those in the control group, and the NRF2 gene loci showed significant difference between two groups. In the athletes group, the mean values of VO2 maxwas significantly different among three genotypes. That is to say, these three genetic polymorphisms may be the biomarkers to predict the elite endurance athlete status, but the mechanism needs to be studied in depth.【总页数】6页(P2508-2513)【作者】魏琦;范家成;杜亚雯【作者单位】湖北省体育科学研究所,湖北省武汉市 430205;湖北省体育科学研究所,湖北省武汉市 430205;湖北省体育科学研究所,湖北省武汉市 430205【正文语种】中文【中图分类】R318【相关文献】1.Sirt1基因多态性与有氧耐力表型的关联研究 [J], 金晶;冯燕;卢健;陈彩珍;何子红2.PPARδ基因多态性杰出有氧耐力表型的microRNA调控特征关联分析 [J], 王芳;段立公;徐思3.KDR基因多态性的杰出有氧耐力表型与运动应激诱导的循环microRNA差异表达谱的关联研究 [J], 许英樱;段立公;徐思4.四种基因位点多态性与运动员耐力表型的关联 [J], 魏琦;范家成;杜亚雯;5.青少年游泳运动员睾酮表型水平、免疫因子与心肺耐力的关联研究 [J], 费梓航;李世昌因版权原因，仅展示原文概要，查看原文内容请购买。