水稻胚乳细胞增殖动态分析及其与籽粒生长的关系

Proliferation of Endosperm Cell and Its Relation to the Growth of Grain in Rice

以一中熟粳稻品种和两个中熟籼型三系杂交稻为材料,观察了不同粒位籽粒胚乳的细胞增殖动态和细胞充实过程,在以Richards方程模拟的基础上进行生长分析,结果表明:胚乳的细胞增殖速率的变化呈单峰曲线,但相对增殖速率在增殖始期最高;强势粒起始分裂势高,花后2.8～3.5天即达最高增殖速率,分裂强度大,活跃分裂期短,为2.89～3.63天,分裂终止期在花后6～8天;弱势粒胚乳细胞增殖起始期迟,分裂速率的变化较缓慢,活跃分裂期达11.6～13.6天,分裂终止期在23天以上,最终细胞数目显著低于强势粒。品种间胚乳细胞数目具一定差异。子房长度的增加与胚乳的细胞增殖近于同步。强势粒胚乳的细胞增殖与干物质积累有明显的阶段性,弱势粒胚乳的细胞增殖和单细胞物质重量的增加在时间上近乎重迭。

One mid-maturity Japonica rice and two mid-maturity three-line hybrids of In- dica rice were used in observating the proliferation and filling of endosperm cell in different posi tion of rice panicle. Simulation with Richards equation was used in analysis of the process of pro liferation and filling. Results showed that dynamic of proliferation rate of endosperm cell relating to days after anthesis appeared to be non-normal distribution with single climax. The initial pro- liferation rate was high at the beginning of proliferation. The initial proliferation potential was high for vigorous grain, the proliferation rate of endosperm cell reached maximum at 2. 8~3. 5 days after anthesis. The proliferation of endosperm cell was active for only 2. 89~3. 63 days and ended at 6~8 days after anthesis. The proliferation of endosperm cell began late in a grain, and the proliferation rate was stable for all the process. The proliferation of endosperm cell was active for 11. 6~13. 6 days, ended at 23 days after anthesis or later. The number of endosperm cell at the end of proliferation was lower in weak potential grain than that in vigorous grain. The same variation of the endosperm cell number was observed between varieties. The proliferation of en dosperm cell was followed by filling in vigorous grain, while those process almost overlapped in time in weak grain.