The Effects Of 2,4-Epibrassinosteroid Application On Rice Grain-filling And Yield

We studied the dynamic changes of sucrose content and sucrose metabolism enzymes activity in rice grains under 2,4-epibrassinosteroid and Brz treatment conditions. The correlation between these dynamic changes and dry matter accumulation was analyzed. We figured out the mechanism of brassinosteoid increase rice filling and yield in the physiological level of sucrose metabolism. The following results were obtained.1. BR significantly promoted the rice starch and dry matter accumulation, and thus increased rice yield; the yield of Nipponbare and 9311 were increased by 9.86%and 10.31%.2. BR significantly increased the sucrose synthase (SS) activity and promoted grain sucrose degradation. The content of starch precursor was increased and it promoted the synthesis and accumulation of starch.3. BR significantly increased the invertase activity and alleviated the feedback inhibition of enzymatic reaction products, thus promoted the hydrolysis of sucrose, increased grain content of the starch precursor, thereby promoted synthesis and accumulation of starch.4. The function of Brz to rice grain-filling was contrary to BR.5. The activity of SS, NI, AI in Nipponbare and 9311 gains were significant positive correlation to dry weight. The starch content of Nipponbare and 9311 were significant positive correlation to dry weight, too. The correlation between sucrose content and dry weight was not significant.