Molecular Physiological and Ecological studies on the Plant Hormonal Regulation in Rice Production.

点击翻译按钮获取中文摘要

We studied on the physiological and ecological mode of action of plant hormones and their regulatory action in plant growth and development of rice life cycle including vegetative and reproductive growth, especially grain filling. We also used soybean plant as the experimental materials. These are important staple food plants not only in Japan, but also in the world.1. In rice life cycle, 2nd leaf blade in 2nd leaf stage greatly produced ethylene under light condition deferent from 3rd leaf in 3rd leaf stage including other leaf stage, 2nd leaf expressed special character different from other leaf in ethylene production with big amount of sugar contents (Starch and sucrose). Most leaf sheath in various leaf stage, colum in flowering and ripening growth stage, and maturing panicle also had light (round 8,000 lux) promotion effects for ethylene production. This was one of our new finding results.2. Empty panicle after flowering in male sterile and female sterile mutants rice lines had not so much ethylene production deferent from normal panicles under the light condition. We found that it was closed relation ship between the sugars accumulation and the remarkable ethylene production in matured rice panicles (especially in milk-ripe growth stage).3. It was strongly indicated that the appropriate concentrations of endogenous gibberellin should be present in whole plant at panicle initiation stage at the transit stage from vegetative to reproductive for determination of rachis and grain numbers. Brassinolide, one of new plant hormones, activated percent of maturation grain rate and the ripening under low temperature condition in rice. Endogenous abscisic acid content had also closed relationship with soybean maturation.