杂交中稻组合间的粒重稳定性与其库源结构的关系

Relationship between Grain Weight Variation and Sink-source Characters of Mid-season Hybrid Rice

以26个籼型杂交中稻组合为材料,通过剪叶、疏花及密度和氮肥处理,研究了杂交组合间千粒重的稳定性及其与穗部性状和库源结构的关系。结果表明,26个杂交组合千粒重的极差为1.08～4.39g,极差变异率为3.65%～14.54%,变异系数为1.42%～5.42%,千粒重的变异度与组合间每穗着粒数呈显著正相关。原因在于,随着杂交组合间着粒数的增加,齐穗期单位颖花占有绿叶的干物重减小,以致千粒重的极差、极差变异率和变异系数增大。每穗着粒数≤146粒的杂交组合,其千粒重的极差应≤1g,可作为不需要通过栽培措施提高籽粒充实度的临界参考指标。

26 medium indica rice hybrids were used to study the relationship between the variation of grain weight and panicle and sink-source characters in mid-season hybrid rice by removing leaves, reducing spikelets, different planting density and applied nitrogen. The results showed that the range of 1 000-grain weight was 1.08 - 4.39 g, with a variation rate of 3.65% - 14.54% and the CV of 1 000-grain weight was 1.42% - 5.42% among the tested 26 hybrids. There was a significant positive correlation between the variation of 1 000-grain weight and the number of spikelets per panicle of the hybrids. The reason was that the dry weight of green leaves per spikelet in full head- ing stage decreased with an increase of the number of spikelets per pancile, resulting in an increase of the range, range rate and CV of 1 000-grain weight. The hybrids with the number of spikelets per panicle below 146 would have a range of 1 000-grain weight below 1 g, which could be used as a critical diagnosing index unnecessary to take measures to improve grain plumpness in rice cultivation.