不同产量潜力玉米籽粒胚乳细胞增殖与籽粒充实期的生理活性

不同产量潜力玉米间单籽粒的胚乳细胞数目差异显著，高产潜力玉米多于中产和低产潜力玉米，中产潜力玉米又多于低产潜力玉米。籽粒的生理状态影响着籽粒灌浆。籽粒灌浆速率、籽粒淀粉磷酸化酶活性及GA3含量的动态变化在时间进程上基本一致，籽粒淀粉磷酸化酶活性及GA3含量对籽粒物质充实有直接作用，其较高含量利于籽粒的干物

Physiological Activities and Multiplication of Endosperm Cell at Filling Stage of Kernels with Different Yield Potential in Maize

In China, the yield of kernels in maize ha d been increased in large scale from 1 340 kg/ha to 4 500 kg/ha during more than 50 forepassed years. The main reason is the increasing of yield potential of c ultivars besides the improving of production condition and cultivation technolog y. The results in this paper showed that there was a distinct difference betwee n the mean number of endosperm cells in a kernel of 3 cultivars with different y ield potential in maize. The number in yield potential maize was more than that in middle or low yield potential maize, and the number in middle yield potenti al maize was more than that in low yield potential maize also. The number of en dosperm cells of a kernel on the top of the ear was the least one of 3 cultivars , the number of endosperm cells of a kernel in the billow of the ear was the mo st one of 3 cultivars. The filling rate of kernels was evidently affected by ph ysiological activity of kernels. The curve trend of kernel filling rate was the same as that of the starch phosphorylase activity and GA 3 content in kernel. It means that, the higher activity of starch phosphorylase and the content of GA 3 in kernel, the faster kernel filling speed. The activity of starch phosp horylase and the content of GA 3 directly affected matter accumulation of kerne ls. Multiplication of endosperm cells and dry matter accumulation in kernel wer e affected by the content of iPAs(isopentenyladenosine group), IAA, ABA and ac tivity of invertase in kernels indirectly. The higher the content of iPAs, IAA and activity of invertase in kernel, the faster the multiplication of endosper m ce lls and matter accumulation in kernels. High content of ABA in kernels hindered the multiplication of endosperm cells and the dry matter accumulation in a kern el. With the rising of yield potential in maize, the activity of ATPase, the content of ATP and filling rate of kernels rose.