从寒丰A、秀水-04A与R378等组合看杂交粳稻库源特征及对籽粒充实度的影响

CHARACTER OF JAPONICA RICE'S SOURCE AND SINK AND ITS EFFECT ON GRAIN FILLING DEGREE FOR SOME CROSS COMBINATIONS OF HANFENG A,XIUSHUI-O4A AND R378ETC

以目前大面积生产应用的2个粳稻不育系“寒丰A”、“秀水一04A”和R378等3个粳型恢复系配组成5个杂交组合，分析了杂交粳稻的库源特征及其对籽粒充实度的影响。结果表明，杂交粳稻产量库容优势明显，且这种优势主要表现为穗大；杂交粳稻抽穗期叶面积大、茎鞘干物质输出率高；成熟期杂交粳稻虽然叶面积下降幅度较小，但单位颖花获得的干物质量不如亲本和常规粳稻的多，而且，由于抽穗后期的干物质生产量对籽粒贡献最大，故杂交粳稻后期源库比例失调，因而籽粒充实度低下，但杂交粳稻出穗前干物质生产对籽粒充实度具有正效应。

An experiment was carried out to study the character of source and sink and its effect on grain filling degree of hybrid japonica rice by using 5 hybrid combinations be-tween 2 largely extended japonica sterile lines "Hanfeng A", "Xiushui-O4 A" and 3 japonica restorers. The results are as follows. The hybrid japonica rice's production sink volume has a distinct predominance,mainly lies in large panicles. The leaf area of hybrid japonica rice is large and the export rate of dry matter from stem sheath is high before earing,and the de-crease of leaf area is comparatively small after earing,but the amount of dry matter obtained for unit spikelet is also smaller than that of parents and japonica rice varieties developed from pure line selection. In addition,the amount of dry matter formed after earing conttributes the most to the grain yield. So the aberration of the ratio between source and sink in the later growth period is the major cause of the low grain filling degree of the hybrid japonica rice;but,the dry matter reserve before earing has a positive effect on grain filling degree.