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THE ROLE OF PLANT HORMONE AND CARBOHYDRATE IN THE GRAIN FILLING OF RICE PLANT

植物激素和碳水化合物在水稻籽粒灌浆中的作用

基本信息

批准号：
12660010
负责人：
NAKAMURA Teiji
金额：
$ 2.3万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

The purpose of this study is to elucidate the role of phytohormone and carbohydrate in the grain filling of rice.1. Early growth and dry matter accumulation of grainsShading after the heading decreased the early growth rate and increased the linear dry matter accumulation rate in the grain at the lower spikelet positions. Both the shading before the heading which reduced the carbohydrate content at the heading and elevated CO_2 after the heading had no effects on the early grain growth, but increased the linear dry matter accumulation rate in the grain. These results suggest that lights promote the early grain growth not through the increment of carbohydrate supply, but through phytohormone which concerned with the grain growth and the endosperm development.2. Diurnal changes of the early grain growthGrains were expanded and cells of maternal tissue were divided during the day at the early developmental stage. The level of abscisic acid was higher in the day than in the night, but the level of cytokinin was higher in the night than in the day. Sugar pool sizes of grains did not show the clear diurnal change. These results suggest that light regulates the early grain growth through the abscisic acid and, abscisic acid acts as a growth promoter.3. Varietal differences in early grain growth and characteristics of grain fillingUnder the defoliated condition, there was a varietal difference in the degree of the growth delay of the grains at the lower spikelet positions within panicle. The variety in which the early gram growth is difficult to delay had higher endosperm cell number and final grain weight than the variety in which the growth is easy to delay. It seemed to have to elucidate the varietal difference in the early grain growth, physiologically.

本研究旨在阐明植物激素和碳水化合物在水稻籽粒灌浆中的作用.抽穗后遮光降低了籽粒的早期生长速率，提高了下部颖花籽粒干物质的线性积累速率。抽穗前遮光降低了抽穗期碳水化合物含量，抽穗后增加CO_2浓度，对籽粒早期生长无影响，但提高了籽粒干物质线性积累速率。这些结果表明，光照不是通过增加碳水化合物供应来促进籽粒早期生长，而是通过与籽粒生长和胚乳发育有关的植物激素来促进籽粒早期生长.籽粒发育早期的日变化在籽粒发育的早期，籽粒在白天膨大，母体组织细胞在白天分裂。脱落酸含量白天高于夜间，细胞分裂素含量夜间高于白天。籽粒糖库大小的日变化不明显。这些结果表明，光通过脱落酸调节小麦籽粒的早期生长，脱落酸具有生长促进作用.籽粒早期生长和灌浆特性的品种差异在去叶条件下，穗内下部颖花籽粒生长延迟的程度存在品种差异。早期克重难以延缓的品种胚乳细胞数和最终粒重高于早期克重易延缓的品种。这似乎必须阐明品种在早期籽粒生长生理上的差异。