Relationship Between Endogenous Hormone And Fruit Color During Plum Fruit Development

This paper studied the relationship between endogenous hormone and the color ,and dynamic laws of content of pigment ( anthocyanin, chlorophyll, carotenoid, flavonoid) ,hormone, sugar, using plum fruits from 6—year or 7 —year plum trees as experimental materials. The results showed that:1. The fruit color of skin depended on the color substances in plum fruit. The red color of Ooisowase and Angeleno was was resulted by the accumulation of anthocyanin and red grade was due to the content of anthocyanin;the yellow color depended on the accumulation of carotenoid and degradation of chlorophyll while the green color of Kaers depended on the high content of chlorophyll.2. The content of endogenous hormone ZT,GA₃, IAA in peel, flesh, seed varied obviously during plum fruit development. The trend following that: the content of hormone reached the peak in the stage of fruit rapid development , then reduced quickly and reached the bottom in the stage of fruit maturation;the content of ABA and ethylene significantly increased in the later stage of fruit development;the content of GA3,IAA,ZT,ABA in the early stage of fruit development followed that: seed>flesh>peel.3. The content of soluble sugar, reducing sugar , fructose and sucrose increased clearly in the fruit development and reached the peak in the maturation stage;the content of these above followed that: flesh>peel. The content of ABA and ethylene was positively correlated to the content of sugar while IAA and GA3 was negatively correlated to it. Different breeds had different results.4. The activity of PPO increased in the fruit development;the ABA content of four strains of plum fruit was positively correlated to the PPO activity while GA3 content was negatively correlated to it. The law of correlation with different strains was a little different. PAL activity in peel and flesh decreased in the early fruit development stage then increased. Only IAA content of Ooisowase and "ZaoShengYueGuang"was negatively correlated to PAL activity .Other strains were not.5. Anthocyanin content increased rapidly as nearly reached the maturation stage;chlorophyll content reduced;carotenoid and flavonoidfirstly decreased then increased;ethylene content was positively correlated to anthocyanin and carotenoid;GA₃ content was positively correlated to chlorophyll and flavonoid;IAA content of "ZaoShengYueGuang"Was positively correlated to carotenoid;ABA content waspositively correlated to anthocyanin.6. During fruit development stage , the relationship of the main pigment, hormone, sugar and activity of PPO and PAL followed that:the effects of sucrose in flesh of Ooisowase on anthocyanin in peel was the most significant and path coefficient(P) was 0.538,the second one was the sucrose in peel;the strain of Angeleno had similar condition. Its path coefficient was 1.538. For Ooisowase and Angeleno, direct path coefficient of ethylene content with anthocyanin content in peel were 0.274 and 0.678 respectively, and the effects of ethylene content on anthocyanin were the largest by sucrose in flesh, and the indirect path coefficient were 0.436 and 0.539 respectively. Direct path coefficient of ABA content with anthocyanin were 0.230 and 0,930 respectively, and also, the effects of ABA content on anthocyanin were the largest by sucrose in flesh, and the indirect path coefficient were 0.564 and 0.564.Ethylene content of "ZaoShengYueGuang"had positive effects on carotenoid in peel, and the direct path coefficient was 0.521;ABA in peel inhibited synthesis of chlorophyll, and the direct path coefficient was -0.976.Inhibiting effects of ABA in peel on chlorophyll was the largest, and the indirect path coefficient was 0.727;For Kaers, the content of GA3 in peel and IAA in flesh improved chlorophyll content in peel, and GA3 in peel had the largest effect, and the direct path coefficient was 1.317.GA3 in peel inhibited ABA antipathogenic effect, so that indirectly inhibited chlorophyll degradation.7. Seed is the location of hormone synthesis. However, hormone in seed had no obvious effects on the color substances through the analysis of path coefficient for four strains .Results showed that hormone in peel and flesh was mainly responsible for the color substances.