水稻籽粒受容活性及其控制 Ⅳ.汕优63不同部位籽粒的结实能力

GRAIN CAPACITY ACTIVITY AND ITS REGULATION IN RICE Ⅳ. SPIKELET FERTILITIES ON DIFFERENT PANICLE PARTS OF SHANYOU No. 63

1988～1991年,在群体水培条件下,采用大穗型中籼杂交稻汕优63,设计不同生育期氮、磷处理21个,改变结实期灌浆物质的供应水平,研究稻穗上、中、下部一、二次枝梗籽粒的结实能力。结果表明:在灌浆物质供应水平较低时,不同部位籽粒的结实率、千粒重大小与开花早迟顺序一致,随着灌浆物质供应水平的提高,迟开颖花的结实率、千粒重可超过先开颖花,一、二次枝梗籽粒表现有类似趋势,证明迟开颖花的生理劣势可以转变;提高颖花根活量能明显提高稻穗不同部位籽粒的结实率和千粒重,挺高幅度一、二次枝梗籽粒均表现为下部>中部>上部,当颖花根活量达到一定程度时,迟开颖花的千粒重将高于先开颖花。

The experiments were carried out in 1988～1991 under hydroponical cultrure condition with mid-maturity large panicle hybrid indica rice Shanyou No.63. With 21 trcatmeants of nitrogen and phorsphorous supply, differed available grain filling substances levels were attained in the filling stage. Spikelet fertilities on upper, middle, lower primary and secondary branches were analysed. Results showed:The precedence of fulfilled grain percentages, 1000-grain weights on different panile parts were in coincidence with flowering precedence, when the available filling substances was insufficient. When the available filling substances was abundant, the fulfilled grain percentages and 1000-grain weights of the late flowered spikelets could surpass those flowered early on both the primary and secondary branches. Those proved that the inferiority of the late flowered spikelet could be shifted. Promoting spikelet root activity could significantly improve the spikelet fertilities on different parts of the panicle, the increments of the fertility in the weak spikelets was obviously higher than those of so called vigorous spikelet. The 1000-grain weights of weak spikelet would be higher than those of vigorous spikelet when spikelet root activity surpassed a certain point.