影响玉米单叶水分利用效率内在因素的研究

Studies on the Factors Effecting Leaf Water Use Efficiency of Maize

本试验采用不同基因型玉米自交系和杂交种对玉米单叶水分利用效率（WUE）的研究表明以下5点。（1）高水分利用效率的玉米基因型其光合速率（PH），蒸腾速率（TR）也较高，而气孔阻力（RS）较低。WUE与PH，TR和RS存在显著的线性关系，YWUE＝2．3613＋0．051SXPH＝0．1093XTR＝0．399ZXRS，R＝0．934。逐步回归的结果，也可用PH预测WUE，YWUE＝0．7211＋0041SXPH，R＝0．897.（2）直立、平展、中间三类株型玉米基因型间的WUE差异不显著。（3）随着叶片的衰老，玉米叶片的RS值显著增高，而PH较TR下降的更快，因此WUE逐渐降低。（4）WUE与RS在本试验各种条件下多表现为弱的负相关，进一步证实提高WUE应首先从提高单叶PH入手。（5）叶片叶绿素含量可作为鉴定、筛选玉米WUE品种资源及高WUE育种的参考指标。

Seventeen inbred lines and ten hybrids of maize were used to examine water use efficiency (WUE) and factors affecting it in this project. The results showed: High WUE genotypes ranked high with respect to leaf photosynthesis (PH), transpiration (TR), but lower in stomatal resistance(RS). There was a significant linear correlation be-tween WUE and PH,TR,RS:YWUE= 2. 361 3+0. 051 8XPH- 0. 109 3XTR-0. 399 2 XRS. R =0.934. WUE also could be forcasted with PH:WUE= 0. 7211 +0.041 5XPH,R= 0. 897. WUE showed no significant difference between erectl flat and middle plant-types of maize. With leaf growing old,RS increased,PH, TR and WUE decreased. The present results suggests that concent of leaf chlorophyll could be a referential index to select and appraise high WUE genotypes.