不同粒型小麦品种籽粒内源激素变化与籽粒灌浆特征的比较

选用2个粒重差异较大的小麦品种济麦20(小粒型)和山农710331(大粒型),对比研究其籽粒发育过程中4种主要内源激素(IAA,GAs,ZR和ABA)的含量变化及籽粒灌浆特征。结果表明,2个品种内源激素含量变化动态趋势基本一致,但品种间内源激素含量存在基因型差异。在籽粒发育过程中,IAA,GAs和ZR含量呈籽粒发育前期高、后期低的趋势,而ABA含量呈“V”型曲线变化。用Logistic方程拟合籽粒灌浆过程可以看出,籽粒灌浆启动时间、灌浆速率以及灌浆持续时间共同决定小麦最终籽粒重的高低。与小粒型品种济麦20相比,大粒型品种山农710331籽粒发育初期较高的ZR含量使其籽粒灌浆启动时间早;在整个籽粒发育过程中较高的GAs,ZR和ABA含量与较高的籽粒灌浆速率相联系;籽粒发育后期较高的ZR含量及相对较低的ABA增幅,可能是其籽粒灌浆持续时间较长的一个重要原因。

Hormonal Changes in Relation to Filling Characters in Developing Grains of Two Wheat Cultivars Differing in Grain Size

The concentration of endogenous hormones in developing grains was one of important factor to regulate and control wheat grains growth.In order to investigate the relationship between dynamic changes of endogenous hormones in developing grains and their characteristic of wheat grain filling,two wheat cultivars,JM20(small grain size) and SN710331(large grain size) were used in this experiment.The concentrations of IAA,GAs,ZR,and ABA in developing grains,as well as the kernel weights were determined during grain filling.The results showed that dynamic changes of endogenous hormones were similar between two wheat cultivars.However,there were significantly genotypic differences between their endogenous concentration.The concentration of IAA,GAs and ZR were high in early grain filling,and low in late grain filling.The changes of ABA concentration showed 'V' curve,and the ABA concentration reached the lowest at 21 days after anthesis.Simulating the process of grain filling with Logistic Equation showed that it was early initiating time,high grain filling rate and long grain filling duration that determined the high kernel weight of SN710331.After it was analyzed that the relationship between the changes of endogenous hormones and the grain filling of two wheat cultivars.The results suggested that the differences of endogenous hormones were probably the reason that kernel weights were different between the cultivars.Endogenous hormones affected grains filling,and then influenced wheat kernel weight.The ZR concentration at the early grain filling,the concentration of GAs,ZR and ABA at whole grain filling of SN710331 were higher than that of JM20.And it probably advanced the initiating time and enhanced the strength of grain filling.At late grain filling,the high ZR concentration and relative low increased extent of ABA concentration of SN710331 were likely to prolong the length of grain filling duration,compared with JM20.