大气NH3浓度升高对不同氮效率玉米生理指标及生物量的影响

植物生态学报　2008,32(1)204～211 ΞJ ournal of Plant Ecology(Chinese Version)

大气NH3浓度升高对不同氮效率玉米生理

指标及生物量的影响

陈小莉1　李世清1,23　任小龙2　强　虹2　吉春容2　闫登明2

(1中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌　712100)

(2西北农林科技大学资源环境学院,陕西杨凌　712100)

摘　要　该试验采用开顶式气室(Open top chambers)装置,在两种大气NH3浓度水平(大气背景浓度值为10nl・L-1

和高NH3浓度1000nl・L-1)和两种供氮介质水平(高供氮介质和低供氮介质)下,对两种氮效率玉米(Zea mays)基

因型(‘氮高效5号’(NE5)和‘氮低效四单19’(S D19))的叶绿素指标值(S P AD值)、净光合速率(P n)、气孔导度(G s)、

生物量和根冠比等生物学和生理学指标进行了测定。结果表明,大气NH3浓度升高对两种氮效率玉米基因型各生

理指标有显著影响(p<0.05)。与大气背景NH3浓度相比,当大气NH3浓度为1000nl・L-1时,生长在高供氮介质

中‘氮高效5号’的S P AD值、P n和G s分别降低7.0%、14.0%和6.5%,而‘氮低效四单19’的对应指标分别降低

9.0%、11.0%和6.9%;生长在低供氮介质中的两种氮效率玉米基因型各生理指标均显著增加(p<0.05):‘氮高效

5号’的S P AD值、P n和G s分别增加5.7%、7.1%和17%,‘氮低效四单19’的对应指标分别增加7.0%、11.0%和

22.0%。高供氮介质中NH3浓度升高对氮低效基因型玉米冠层生物量抑制作用小于对氮高效基因型玉米的抑制效

应,而低供氮介质中NH3浓度升高对氮高效基因型玉米冠部的促进作用显著高于对氮低效基因型玉米的促进作用

(p<0.05);两种大气NH3营养下玉米根冠比的变化与采样时期有关。说明从大气中吸收NH3有利于改善生长在

低供氮介质上玉米的氮素营养状况,而且对氮低效基因型玉米的促进作用比对氮高效基因型玉米更加显著。

关键词　玉米　NH3浓度升高　氮效率　基因型　生理指标

INF L UENCE OF INCREASE D ATMOSPHERIC NH3ON PH YSIOLOG Y IN DEX AN D

BIOMASS OF MAIZE WITH DIFFERENT N EFFICIENCY

CHE N X iao2Li1,LI Shi2Qing1,23,RE N X iao2Long2,QI ANG H ong2,J I Chun2R ong2,and Y AN Deng2Ming2

1State K ey Laboratory o f Soil Erosion and Dryland Farming,Institute o f Soil Erosion and Water Conservation,Chinese Academy o f Sciences,Yan2

gling,Shaanxi712100,China,and2College o f Resources and Environment Sciences,Northwest A&F Univer sity,Yangling,Shaanxi712100,

China

Abstract　Aims　The main aim of this study was to investigate the response of various physiology indexes,

e.g.,chlorophyll index value(stand for the relative content of chlorophyll,S P AD value),net photosynthetic

rate(P n),stomatal conductance(G s),and root shoot ratio(R/S)in tw o genotypes of maize(Zea mays)to

NH3concentration enrichment.

Methods　We grew maize on H oagland s olution in PVC pots in open top chambers(OT Cs).The experiment

was a split2split plot design,which main treatments were tw o NH3concentrations(10and1000nl・L-1).The

sub2plot treatments of the experiment were tw o levels of nitrogen(high and low),and sub2sub2plot treatments

were tw o N efficiency genotypes(high N efficiency,‘NE5’,and low N efficiency,‘S D19’).Air flow in

OT Cs was controlled by small fans and atm ospheric NH3concentration was measured accurately by tw o methods

(NH3determination tubes and G T L2C atm osphere detecting apparatus).

Important findings　Under elevated atm ospheric NH3,there were significant differences(p<0.05)for

physiology indexes between the tw o varieties,‘NE5’and‘S D19’.Under high N medium,com pared with10

nl・L-1atm ospheric NH3concentration,the S P AD value,P n and G s of‘NE5’treated with1000nl・L-1de2

creased7.0%,14.0%and6.5%,respectively,and the corresponding targets of‘S D19’decreased9.0%,

11.0%and6.9%,respectively.Under low N medium,various physiology indexes of the tw o varieties signifi2

cantly increased,i.e.,the S P AD value,P n and G s of‘NE5’increased5.7%,7.1%and17%,respec2

Ξ 收稿日期:2006210230　接受日期:2007202203

基金项目:国家自然科学基金(30571116和30670326)

　3通讯作者Author for correspondence　E2mail:spl@