阿魏酸对西瓜种子幼苗生长及生理生化的影响

西 瓜 是 一 种 深 受 大 众 欢 迎 的 夏 季 水 果 ，近 年 来，我国西瓜的种植面积不断扩大，但由于我国耕 地面积有限，同时西瓜的经济效益高，在部分地区 形成了基地化、设施化的栽培模式，这种长期在同 一地块上连续种植西瓜的习惯导致西瓜产量、品质 下降及病害加剧，造成连作障碍。这种情况随着连 作茬数的增加而不断加重，严重影响了西瓜的生产 效益。连作障碍的一个重要原因是西瓜的自毒作
2016，29（7）：14-18
中国瓜菜
试验研究
阿魏酸对西瓜种子幼苗生长及生理生化的影响
徐小军 1，吴 莉 2，张桂兰 1
（1. 中国农业科学院郑州果树研究所 郑州 450009； 2. 中国科学院武汉植物园 武汉 430074）
摘 要：阿魏酸是西瓜分泌的化感物质之一，在西瓜自毒作用中具有重要的作用。选用质量浓度为 0~1 000 mg·L-1 的阿魏酸浸泡处理西瓜种子，观察西瓜种子的萌发、生长，并检测处理 7 d 后幼苗不同部位生理生化指标的变化。结 果表明，阿魏酸对种子的萌发没有影响，但显著降低了种子活力指数，抑制了根和茎的伸长及鲜质量的增加。随着 阿魏酸质量浓度的提高，根和茎中的超氧阴离子浓度及膜质过氧化程度显著增加，抗氧化酶活性过氧化氢酶（CAT） 的活性也显著提高，而过氧化物酶（POD）和超氧化物歧化酶（SOD）的活性则呈现先升后降的趋势，苯丙氨酸解氨酶 （PAL）活性也呈现先升后降的趋势，并导致西瓜根中酚酸类物质的质量浓度持续升高。说明西瓜幼苗抗氧化系统的 激活能在一定程度上降低酚类物质的影响，阿魏酸可能通过在根中过量积累酚类物质而影响根的生长与发育。 关键词：西瓜；种子；幼苗；酚酸；化感作用；抗氧化；苯丙氨酸解氨酶
Physiological and biochemical effects of ferulic acid on watermelon seed⁃
ling and its growth
XU Xiaojun 1, WU Lu Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, Henan, China; 2. Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, Hubei, China ) Abstract: Ferulic acid is one of allelochemicals secreted by the roots of watermelon, which plays an important role in the au⁃ totoxicity process. In this study, ferulic acid ranging from 0 to 1 000 mg·L-1 was used to treat the seeds of watermelon, subse⁃ quently, seed germination, seedling growth, as well as the cellular physiological and biochemical changes was monitored af⁃ ter 7 days. The results showed that ferulic acid had no significant effect on seed germination, while it significantly reduced seed vigor index, inhibited the elongation of roots and shoots along with the their fresh weight. Superoxide anion radical and lipid peroxidation both in the roots and shoots increased significantly with the increased ferulic acid concentration, at the same time, the antioxidant enzyme activities of catalase (CAT) increased accordingly, while the activities of peroxidase (POD) and superoxide dismutase (SOD) significantly increased firstly and then decreased, similar response pattern was ob⁃ served in the activity of phenylalanine ammonia-lyase(PAL). Consequently, the concentration of phenolic acid in watermel⁃ on seedling roots increase steadily. These results indicates that the activation of antioxidant enzyme can reduce the injure im⁃ posed by the phenolic compound accumulated in root in watermelon seedlings, and the effect of ferulic acid on root growth and development can be attributed to excess accumulation of phenolic compound. Key words: Watermelon; Seed; Seedling; Pherulic acid; Allelopathic effect; Antioxidant activity; Phenylalanine ammo⁃ nia-lyase