水稻抽穗期茎鞘中储存的可用性糖与籽粒充实的关系

用抽穗期茎鞘中可用性糖（可溶性糖＋淀粉）的累积量与颖花数之比，即糖花比表示灌浆始期每朵颖花具有的物质积累。一般抽穗期糖花比高的品种（组合），灌浆初期籽粒中的ＩＡＡ和ＡＴＰ含量、ＡＴＰ酶活性、谷粒充实率和千粒重亦高，它们之间呈极显著正相关。增加抽穗期的糖花比，灌浆初期的籽粒生理活性和谷粒充实率提高，抽穗期糖花比减小，结果则相反。表明抽穗期茎鞘中储存的可用性糖不仅是籽粒灌浆物质的一部分，而且对提高灌浆初期籽粒库的活性、启动和促进籽粒灌浆起重要作用。

RELATION OF THE USABLE CARBOHYDRATE RESERVED IN STEMS AND SHEATHS AT HEADING STAGE WITH GRAIN FILLING IN RICE PLANTS

The ratio of usable carbohydrate (soluble sugars starch ) reserved in stems and sheaths at heading stage to spikelets, i e carbohydrate spikelet ratio was used to express matter accumulatin per spikelet at initial grain filling In general, content of IAA and ATP, ATP ase activity in grains at early stage of grain filling, and plump grain percentage and 1000 grain weight were high for the varieties (combinations) with high carbohydrate spikelet ratio at heading stage They possitively and significantly corrected The physiological activity of grains at early filling stage and plump grain percentage were raised when carbohydrate spikelet ratio at heading stage increased, and the results were reversed when the carbohydrate spikelete ratio reduced The results suggested that the usable carbohydrate reserved in stems and sheaths before or at heading stage not only be a part of the matter used in grain filling, but also play an important role in raising sink activity, switching on and promoting grain filling in rice