杂交中稻源库比对籽粒充实的影响及其高产组合的源库特征

 以18个杂交中稻组合为材料，在稀植高氮与密植中氮两种栽培条件下，研究了籽粒充实度与源库结构关系。结果表明，源库比是影响籽粒充实度的重要因素之一，主要影响中、下部籽粒，对上部籽粒影响极小。反映籽粒充实特征的结实率、充实率和充实指数3个指标中，充实指数受源库比的影响最敏感，其次是结实率，充实率最差。在保证理论产量和产量潜力分别达9 t和11 t,结实率不低于80%的高产前提下, 相应组合的源库特征的最佳取值范围: 每穗着粒数160～220粒，每公顷有效穗180万～210万，千粒重28～30 g,叶粒比6.66～7.52 mg/粒，结实率80%～90%，充实率96.5%～97.5%，充实指数78%～87%，单穗重4.3～5.0 g。

Effect of Source-sink Ratio on Grain Filling and The Source-sink Characteristics of High Yield Varieties of Mid-season Hybrid Rice

Effect of source-sink ratio on grain filling was investigated via 18 mid-season rice hybrids with two cultural methods. The results showed that there was a high significant effect of source-sink ratio on grain filling, and the effect was mainly in the middle-lower part of a panicle, rather than the upper part of a panicle. The most sensitive index for effect of source-sink ratio on grain filling was grain plumpness index>seed setting percentage >grain filling rate. High-yield combinations with 9 t theory grain yield, 11 t potential grain yield and a seed setting percentage of 80% had the following source-sink characteristics: spikelet number 160-220 per panicle, effective panicles180×104-240×104 per hm2, 1000-grain weight 28-30 g,leaf-grain ratio 6.66-7.52 mg per grain, seed setting percentage 80%-90%, grain filling rate 96.5%-97.5%, grain plumpness index 78%-87%, grain weight 4.3-5.0 g per panicle.This study provided a scientific and practical basis for high yield breeding and cultivation of hybrid mid-season rice.