内源IAA对协优9308籽粒灌浆的生理作用

PHYSIOLOGICAL EFFECTS OF ENDOGENOUS IAA ON GRAIN FILLING OF HYBRID RICE XIEYOU 9308

以杂交稻协优 93 0 8及其恢复系中恢 93 0 8为供试材料 ,研究了灌浆初期籽粒中糖分的变化以及吲哚乙酸抑制剂对3H IAA以及3H 葡萄糖吸收分配的影响。结果表明 ,强热粒籽粒的增重速度始终高于弱势粒。受精后 ,强势粒籽粒中果糖、葡萄糖及蔗糖的含量高于弱势粒 ,受精 7d后 ,弱势粒中糖分的含量高于强势粒。强、弱势籽粒间存在的这种与灌浆势有关的差异 ,杂交组合大于其相应的恢复系。吲哚乙酸合成及运输抑制剂抑制3H IAA、3H Try以及3H Glucose在籽粒中的分配 ,降低3H Try向3H IAA的转化效率。外源IAA处理幼穗减小强、弱势籽粒间结实率的差异 ,整穗的结实率也有所提高 ,认为吲哚乙酸是启动杂交稻籽粒灌浆的信息物质。

The progress of grain filling and effects of TIBA and PCIB on sugar content and IAA level in superior and inferior spikelets of hybrid rice Xieyou 9308 and its restorer R 9308 were studied. The grain weight increment rate and sugar (fructose,glucose and sucrose) in superior spikelets were higher than those in inferior spikelets until 7 days after pollination, then, they were higher in inferior spikelets than those in superior ones. The differences of physiological activityies between superior and inferior spikelets were more significant in combinations than in their restorers. IAA inhibitors decreased 3H IAA and 3H Try contents in both superior and inferior spikelets, reduced the efficiency of 3H Try bio transforming to 3H IAA in rice plant and,therefore, reduced 3H glucose in grain. By treatment with high concentration of exogenous IAA on young panicle before heading, the grain setting difference between superior and inferior spikelets was significantly decreased, and the total grain setting rate increased, indicating that IAA impels the grain filling progress in hybrid rice.