| In this experiment the mechanisms of fruit development and maturation of astringent persimmon fruits "Mo Pan" which were planted extensively in He bei and nonastringent persimmon fruits "Fuyu" which were introduced from Japan were studied. The variation of persimmon fruits in development, indogenous(IAA,ABA,ZT and GA3), polyamines (Spd, Spm and Put),tannin substances, pectic substances, organic acid and soluble sugar(fructose, sucrose and glucose) were observed. The differences between nonastringent fruits and astringent ones were also discussed with persimmon fruits developed and matured. Results were such as follows:1 .Results of regularly observing and measuring the increase of fruit fresh weight, diameter and length ,showed that the growth curves of fresh weight, diameter and length were like a double "S" curve.2. With persimmon fruits development, each contents of the soluble sugar, fructose, sucrose and glucose in the fruit changed dramatically. The soluble sugar had two rapid accumulating periods and fructose only had one. During nonastringent persimmon fruits developing fructose and glucose had two rapid accumulating periods, but fructose and glucose had only one during astringent persimmon fruits developing. The soluble sugars accumulation mainly happened at the last stage of the fruit development.3.The contents of organic acid decreased dramatically in nonastringent persimmon fruits at the end of May, by the middle of June they increased gradually until the fruits ripening. In the early stage the changes of organic acid in astringent persimmon fruits were identical with the nonastringent persimmon fruits. But in the middle of the September the contents of organic acid reached the minimum, then they increased gradually until the fruits ripening.4.The contents of tannin substances decreased during persimmon fruits developed. The contents of tannin substances in nonastringent persimmon fruits decreased earlier and faster than that in ones. The levels of tannin substances decreased dramatically in de-astringent persimmon fruits at August. The nonastringent persimmon fruits can be eaten when they collected, but the astringent ones cann' t be eaten because they were40astringent, they need to be treated.5.The pectic substances and protopectic accumulated with the development of persimmon fruit in the early stage of persimmon fruits development which respectively reached a peak value in the middle of August, then they turned to decrease continually with fruit ripening. The contents of soluble pectic in nonastringent persimmon fruits changed little while that in astringent persimmon fruits tended to increase strongly. The ratios of protopectic and pectic were related to the fruits softening. The smaller was the ratio, the softer was the fruit.6.From loosen flower bud to bloom stage, the levels of IAA in nonastringent persimmon fruits increased continually in initial stage, then it turned to decrease until the persimmon fruits ripening. With the persimmon fruits development there were three peaks of IAA levels in astringent persimmon fruits which separately at bloom stage, physiological fruit drop and fruit maturing. IAA was correlated with the rapid growth of fruit and inhibited fruit drop strongly and regulated fruits maturing.7.There were three peaks of GA3 and ABA levels which were correlated with the fruitlet development , physiological fruit drop and fruit maturing. The levels of ABA in nonastringent persimmon fruits were less than that in astringent ones, seeming to be related to the parthenocarpy.S.There were two higher ZT levels during nonastringent persimmon fruits development and there was only one peak value of ZT level with astringent persimmon fruits development. The increase in ZT contents may be a key factor to advance development of fruits.9.The contents of PAs(Put, Spd and Spm)declined gradually during blossom, from loosen flower bud to the fruit drop stage, the contents of PAs tended to decline in young fruit, but the decreasing speeds in nonastringent persi... |
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