【摘要】 水稻（ＯｒｙｚａｓａｔｉｖａＬ．）结实期间，穗上部谷粒的粒重比穗下部谷粒的高，灌浆前期的增重速率比穗下部谷粒的高，在整个灌浆过程中增重速率的变化比穗下部谷粒的快。利用ＥＬＩＳＡ方法对穗上部谷粒和穗下部谷粒中各种内源激素含量的分析表明，在灌浆过程中，谷粒中未检测出ｉＰＡｓ；在穗上部谷粒和穗下部谷粒中，ＡＢＡ和ＧＡ(１＋３)的含量的最大值出现的时间分别与穗上部谷粒和穗下部谷粒增重最快的时间基本一致，无论穗上部谷粒还是穗下部谷粒中，ＩＡＡ的含量基本上均呈下降趋势；ＧＡ(４＋７)的含量是先上升、后下降、再上升；在结实的前中期，谷粒中ＡＢＡ、ＧＡ(１＋３)的含量基本上均是穗上部谷粒高于穗下部谷粒。探讨了各种激素在谷粒灌浆过程中的作用及从激素的角度探讨了穗上部谷粒比穗下部谷粒结实性好的原因。更多还原

【Abstract】 The grain fresh weight and grain-filling rate at early grain deVeloping stage in rice (Oryza sativa L. ) were higher in the upper than in the lower part of panicle during grain filling. The grains in the upper and/or the lower part of panicle were analyzed for the endogenous plant hormones. The results indicated that the peak content of ABA and/or GA1+3 in the developing grains append at about the same stage when the highest increasing rate of grain appeared in the upper and in the lower part of the panicle respetively. After heading, the IAA content in developing grains steadily decreased in ho the upper and the lower part of the panicle, GA4+7 content decreased at first and then increased, and again decreased. At the early grain-filling stage, the ABA and GA1 + 3 contents in the developing grains were higher in the upper than in the lower part of the panicle. The role that the hormones play in the developing grains and the reason why the grains seed set better in the upper than in the lower part of the panicle were discussed.更多还原