遮光对不同基因型玉米叶片衰老和产量的影响

采用盆栽试验,研究了遮光对不同基因型玉米叶片衰老和产量的影响。结果表明,苗期遮光和穗期遮光均使玉米叶面积指数L(AI)降低,但粒期遮光则使玉米生育后期LAI下降减缓。遮光条件下生长的玉米叶片SOD酶活性升高,MDA含量降低。不同时期遮光处理均可导致玉米减产,减产程度为粒遮>穗遮>苗遮。除千粒重和穗粗外,遮光处理对其它穗部性状指标的效应值均达极显著水平。遮光对玉米叶片衰老和产量的效应在不同基因型之间表现出明显差异。

Effects of Shading on the Senescence of Leaves and Yield of Different Genotype Maize

Studies on effects of shading on senescence of leaves and yield were conducted with different genotype maize by pot tests.The results indicated that,Shading at various stages had different effects on maize leaf area index(LAI).LAI decreased because of seedling and ear shading,but slowed the decreasing of LAI during maize later development due to grain shading.Activities of SOD under shading increased compared with control,In contrast,the content of MDA reduced under shading.Shading also resulted in a severe decline in yield,which was also affected by shading stage.Based on the data the magnitude of shading time in terms of yield reduction was: grain shading > ear shading > seedling shading.The effects of shading on ear length,bare top length,kernel number per ear and kernel weight per ear were significant at either P=0.05 or P=0.01,and no significant difference caused by shading existed in ear diameter and kernel weight.In addition,Effects of shading on the senescence of maize leaves and yield were obviously different among different genotype maize.