遮阴对不同品种玉米叶片形态和功能的影响

采用盆栽方法研究了遮阴对不同玉米品种叶片形态和功能的影响。结果表明在全生育期遮阴条件下玉米叶片长宽比增大，叶生物量比和叶质量分数增大，叶面积比增大，比叶面积增大，比叶质量减小；各生育期玉米叶片光合速率随遮阴程度的加重降低幅度加大，玉米开花期叶片光合速率降低幅度大于大喇叭口期和灌浆中期；玉米叶片叶绿素a含量、叶绿素b含量、叶绿素总量增加，叶绿素a／叶绿素b降低。遮阴后叶绿素含量的增高，特别是叶绿素b含量的培加是玉米对低光胁迫的一种生态适应。图1，表2，参16。

Effects of Shading at the Whole Growth Stage on the Leaf Morphology and Function of Different Maize Varieties

The pot experiment was carried out to study the effects of shading at whole growth stage on the morphology and function of leaves for different maize varieties.The results showed that shading in all growth stage increased length and width ratio of leaf, leaf mass ratio,leaf mass fraction,leaf area ratio and specific leaf area, but decreased specific leaf weight. With the increase of shading degrees, photosynthetic rate of maize leaf at each growth stage were decreased,and the decrease of photosynthetic rale at anthesis was greater than that at booting and middle filling stage. Shading at the whole growth stage increased contents of chl a ,b and contents of chl a+ b,but decreased chl a/b.The increase of chlorophyll content after shading, especially chl b content, was an ecological adaptation to low light stress.