Factors to induce the ripening of persimmon fruit and its role for decreasing of astringency during maturation.

柿果实的成熟过程没有明显的跃变型。柿果实在成熟过程中CO_2释放量很低，并检测到微量的乙烯，因此乙烯在柿果实成熟中的作用尚不清楚。本研究旨在明确乙烯是否参与柿果实的成熟过程，以及除乙烯外是否还有其他因素诱导柿果实成熟。1.在对柿果实乙烯释放量进行定期测定时，乙烯释放量与成熟过程的关系尚不明确。而且，当在生长季节期间将内源乙烯施加到树上的果实时，在生长阶段III的处理对促进成熟有效，而在生长阶段II则无效。这些结果表明，乙烯可能是柿果实成熟的一个辅助因子。2.阿坝和赤霉素与果实成熟过程密切相关。果实成熟过程中阿坝含量增加，类赤霉素活性降低。果实的蛋白质组分也发生了显着变化，在过渡时期的生长阶段II至III。在果实成熟过程中，有一种与果实成熟相关的特殊蛋白质，在果实成熟初期出现，在成熟过程中含量增加。3.由于去萼和温度处理对果实发育和后熟过程有很大影响。有趣的是，萼叶切除对果实发育和成熟的抑制与糖代谢有关。与对照相比，去萼果实积累了大量的蔗糖，葡萄糖和果糖减少。这一结果表明，蔗糖水解酶参与了果实的发育和成熟。这一假设应通过进一步调查加以证实。

The ripening process of persimmon fruit do not show a clear pattern of climacteric fruit. CO_2 evolution is very low and trace amount of ethylene has been detected during ripening, so that the role of ethylene for ripening is still obscure in persimmon fruit. The objective of this study is to make clear whether or not ethylene is involved in ripening process and there are other factors except for ethylene to induce ripening in persimmon fruit. 1. When ethylene evolution of persimmon fruit was measured periodically, the relationship of ethylene evolution and ripening process was not clear. And also, when endogenous ethylene was applied to the fruit on the tree during growing season, treatments at growth stage III have been effective to promote ripening, while not being effective at growth stage II. These results indicate that ethylene might be a complementary factor for ripening in persimmon fruit. 2. ABA and gibberellin were closely associated with ripening process. ABA contents increased and activities of gibberellin-like substances decreased in relation to ripening process of fruit. Protein constituents of the fruit were also markedly changed at transition period of growth stage II to III. There is a special protein associated with ripening, which appeared at the initiation of ripening and increased during ripening process. 3. As the results of calyx lobe removal and temperature treatment to the fruit, fruit development and ripening process were greatly affected. Interesting aspect is that the inhibition of fruit development and ripening caused by calyx lobe removal was associated with sugar metabolism. Calyx-removed fruit accumulated much sucrose with decreasing glucose and fructose compared to control fruit. This result suggested the involvement of enzymes for sucrose hydrolysis in the fruit development and ripening. This hypothesis should be certified by further investigation.