两系杂交稻茎鞘物质运转与籽粒充实特性的研究

选用不同类型两系杂交稻组合 ,研究了结实期茎鞘物质运转与籽粒灌浆结实的关系。结果表明 :两系杂交水稻在抽穗后的净光合速率和干物质积累量明显高于三系杂交稻。茎鞘物质的输出率与结实率、充实率、最大灌浆速率、平均灌浆速率呈显著的正相关关系。各组合以下部茎鞘物质积累多、转运率高。茎鞘物质转运启动时间早、运转强度大 ,其转运率高的组合 ,结实率高、充实度好 ,表明早期转运对籽粒灌浆充实的重要性。抽穗期提高糖花比 ,同时在灌浆始期促进茎鞘非结构性碳水化合物向籽粒库运转有利于激发库的活性 ,启动和促进更多的籽粒灌浆 ,减少空秕粒 ,增进籽粒充实。

Characteristics of Carbohydrate Transfer of Stem and Sheath and Grain-filling in Two-line Hybrid Rice

The translocation characters of reserves in stem and sheath and its relation to the grain filling were studied during ripening stage with different types of two-line hybrid rice. The results showed that two-line hybrid rice had obviously higher photosynthetic rate and dry matter accumulation after heading than that in three-line hybrid rice. The percentage of matter in the stem and sheath (EPMSS) significantly and positively correlated with the ripened grains, grain-filling percentage, the maximum grain-filling rate and the mean grain-filling rate. The reserves and its translocation of stem and sheath in basic parts were high in all hybrids. The combination with earlier redistribution and higher amount of translocation of reserves of stem and sheath in the early filling had the higher the translocation rate, higher ripened grains and greater grain-filling percentage. The results indicated the redistribution of reserves in the early filling was important to the grain filling. Improving carbohydrate / spikelet ratio before heading stage and accelerating usable carbohydrate transfer to grains at the beginning of filling were beneficial to the activities of grain-filling, reduced unfilled grains and improved grain plumpness.