在穗生长发育阶段,通过水分仪结合称重法严格控制土壤水分的盆栽试验,研究了不同时段不同程度的水分亏缺对杂交稻产量及其构成因素的影响.结果表明:穗分化至分化后30 d的水分亏缺明显影响稻穗生长发育,颖花数和实粒数显著减少,结实率和千粒重降低,最终籽粒产量显著下降.总粒数减少是此阶段产量下降的主要原因,减产幅度与水分亏缺程度呈正相关,重度控水处理影响最大,其次是中度控水处理,轻度控水处理也有一定影响.全时段和穗分化10 ～20 d的水分亏缺影响最大,其次是穗分化0～10d,穗分化20 ～ 30 d对穗部生长影响不大,但对后续籽粒灌浆结实有一定影响.超级杂交稻国稻6号在此阶段适度控水后复水的生长补偿效应和产量构成因素之间的自动调节优于普通杂交稻汕优63.%During panicle development stage of hybrid rice varieties, with experiment cultivated in pots and contrived simulation of water deficit,method to determine soil moisture by electronic balance and W. E. T Sensor, the effect of water treatments lasting different time and stress level on grain formation was studied. The results showed that both different time intervals and levels water deficit influenced panicle growth and development obviously, numbers of spikelets and filled grains, fertility rate and 1 000-grain weight all decreased, which leaded to the sharp reduction of panicle weight and grain yields. The decrease of spikelets numbers is one of the main reasons leading to yield reduction, secondary, the drop of fertility rate and grain weight. A positive correlation existed between yield drop range and water deficit degree, heavier water deficit had the greater influence than middle water deficit,and lower water deficit had certain influence, too. Water deficit during entire period of panicle growth and 10 -20 d after panicle initiation had the greatest influence,nextly,0 - 10 d after panicle initiation,20 - 30 d after panicle initiation had little influence on the panicle growth, but certain influence on grain filling. Influence degree of super hybrid rice,Guodao 6,was lower than that of normal hybrid rice,Shanyou 63 ,and its automatic adjustment a-bility of growth compensation and yield component factors after enduring moderate water deficit was stronger.
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