钇元素对玉米幼苗水分利用效率的调控  

Effects of Yttrium on Water Use Efficiency of Maize Seedlings

作　　者：迟永刚[1] 黄占斌[1] 

机构地区：[1]中国科学院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,陕西杨陵712100

出　　处：《西北植物学报》2005年第5期948-952,共5页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家"973"课题(G1999011708);黄土高原土壤侵蚀与旱地农业国家重点实验室基金(10501-125)

摘　　要：盆栽实验条件下,研究不同浓度钇元素对玉米幼苗水分生理特性的影响,并分析其对玉米幼苗水分利用效率(WUE)的调控。结果表明,钇用量在干土中的浓度为0～0.05mg/g时,玉米幼苗的根长、根冠比(R/S)、WUE呈升高趋势;当钇用量在干土中的浓度为0.05～0.50mg/g时,玉米幼苗的根长、R/S、WUE呈下降趋势。随着钇用量的增加,气孔导度(Cs)始终呈下降趋势,叶水势(LWP)始终呈升高趋势。钇元素作用下玉米幼苗WUE的提高得益于根系活性的增强和适宜的Cs,使干物质的积累和水分的耗散达到最优值,干土中最佳钇用量为0.05mg/g。A hydroponic experiment was conducted to study the effect of yttrium on physiological characteristics of maize seedlings and then analyze yttrium regulation to water use efficiency of maize seedlings.The results demonstrated that the root lengthen and root-shoot ratio and water use efficiency of maize seedlings tended to decrease where yttrium dosage varied from 0~0.05 mg/g in dry soil,and to decline where yttrium dosage varied from 0.05 to 0.5 mg/g in dry soil;Meanwhile,the stomata conductance and leaf water potential of maize seedlings always tended to decline with increased yttrium dosage.It was analytically shown that yttrium effect of improve water use efficiency of maize seedlings resulted from intensified root vigor and properly regulated stomatal conductance,which made dry matter accumulation and water consumption of maize seedlings best optimized at yttrium dosage of 0.05 mg/g in dry soil.

关 键 词：钇 化学节水 叶水势 气孔导度 根冠比 水分利用效率 

分 类 号：Q945.14[生物学—植物学]