玉米果穗覆膜对籽粒发育的影响

以典型的果穗顶端籽粒败育类型杂交种为材料，在授粉后第2天对大田玉米雌穗用聚乙烯塑料袋进行覆膜处理，考察了处理后籽粒发育过程中内派激素（乙烯、细胞分裂素）、呼吸强度及粒重变化动态。结果表明：覆膜处理明显促进了果穗顶部籽粒的发育，使粒重增加、败育粒减少，但中下部籽粒粒重有不同程度的降低，从而导致穗粒数增加、平均粒重降低。覆膜处理后还表现出预部籽粒在籽粒形成期呼吸强度和细胞分裂素含量明显升高，而乙烯释放量则明显降低，营养物质在果穗上的分布趋于均一化等生理效应。

Effects of Ear Covering Treatment with Polyethylene Film on Kernel Development in Maize

Using the typical type of ear-tip abortive hybrid corn, effects of ear covering treatment with polyethylene film on kernel development, since 2 days after anthesis till to maturity had been observed. The hormone levels and respiration activities of kernels and kernel weight of treated ears were tested and compared. The results indicated that the treatment promoted the development of ear-tip kernels with increased kernel weight and reduced number of aborted ones. Respiration activities and cytokinin levels of ear-tip kernels were increased, but ethylene releasing value decreased. However, weights of kernels in the middle and basal were lower in treated ears than CK. It was suggested that the ear-covering treatment with film change assimilate distribution pattern within maize ear by increasing sink activities of tip kernels.