Effect of High Temperature after Anthesis on Endosperm Cell Deve lopment and Grain Weight in Wheat

The pot experiment was carried out from 1993 to 1995 in Yangzhou to study the influence of high temperature after anthesis on endosperm cell development and grain growth in wheat( T. aestivum L. cv. Yangmai 5 and PH85 4). The main results were as follows. The effect of high temperature after anthesis on grain weight was: treatment 20th～22nd day12th～14th day5th～7th day1st～3rd day28th～30th dayCK. The endosperm cell proliferation rate was increased during a short period after high temperature, but the proliferation duration was significantly shortened, which resulted in the decrease of the maximum endosperm cell number and the decline of grain weight. The high temperature in spike or leaf parts could significantly affect grain weight and spikes was more sensitive to high temperature than leaves. The order of grain endosperm cell number and weight in different positions was not changed under high temperature treatment, but the difference was enlarged.