Research Of Differences Of Endogenous Hormones And Quality In Calyx Persistent Or Fall Off Fruits

Fruits of LaiyangCili and Korla Fragrant Pear were used as materials for studying effect of excising calyx and spraying PBO to fruit development、quality、relative enzyme activities and content of endogenous hormone; fruits of Korla Fragrant Pear were used as materials for detecting dynamic content of IAA、GA3and ABA in calyx and core of young fruits in the critical period of calyx persistent or fall off to study the relationship of endogenous hormone content and proportion and the calyx persistent or fall off. And the same time, we observe the differences of ultrstructure of abscission zone by transmission electron microscope (TEM), detect the activity of cellulose and pectinase; fruits of LaiyangCili and Korla Fragrant Pear were used as materials for studying the best combination of mixed chemicals to promote the rate of pear calyx abscission.The results revealed that:1, The fruit shape of Laiyang Cili could be significantly improved by excising calyx. The content of soluble sugar is higher than that of CK,the titratable acid content is lower, and the diameter of sclereids is shorter; the PAL (phenylalanine ammonia-lyase) activity of the excising calyx fruit is lower than that of CK in previous period of fruit development, and the PODn PPO activity is lower in the mid-stage. Excising calyx is helpful to enhance the comprehensive quality of LaiyangCili. The fruit shape of Kolar Fragrant Pear could be significantly improved by excising calyx or spraying PBO. The content of soluble sugar is higher than that of CK, the titratable acid content is lower, and the diameter of sclereids is shorter; the PAL (phenylalanine ammonia-lyase) activity of the excising calyx fruit is lower than that of CK in previous period of fruit development, and the POD、PPO activity is lower in the mid-stage. Excising calyx and spraying PBO is helpful to enhance the comprehensive quality of Kolar Fragrant Pear.2, The content of GA3in apex of excising calyx fruits is lower than that of persistent calyx fruits in105d after anthesis. The contents of IAA and ABA in apex of excising calyx fruits is lower than that of persistent calyx fruits in prior and meddle period of fruit development. The content of GA3in seeds of excising calyx fruits is lower than that of persistent calyx fruits, and in95-115d is higher. The content of IAA is higher throughout the fruit development. The content of ABA in seeds of excising calyx fruits is higher than persistent calyx fruits in115d after anthesis.The ratios of IAA’ABA in about35d and the ratio of GA3/ABA and (IAA+GA3)/ABA in the middle and later of fruit development in persistent calyx fruits are highter than excising calyx fruits. The contents of IAA and ABA in apex of excising calyx and spraying PBO treated fruits is lower than that of persistent calyx fruits in prior and meddle period of fruit development, the content of GA3in seeds is lower than that of persistent calyx fruits, and in95-115d is higher, the content of IAA is higher throughout the fruit development, the content of ABA in seeds is higher than persistent calyx fruits in115d after anthesis. The ratios of IAA/ABA in about35d and the ratio of GA3/ABA and (IAA+GA3)/ABA in the middle and later of fruit development in persistent calyx fruits are higher than excising calyx and spraying PBO treated fruits.3, Spraying DubangFuxing、PBO、ethephon and PP333individually can promote abscission of sepals,but mixed chemicals can get higher ratio of abscisic calyx and better fruit quality.The best combination is DubangFuxing6000times liquid and PBO300times liquid;4, In8days after full bloom the cell wall of abscission zone cell of shed calyx fruits was degraded, cell function was decreased. The relationship of the abscission of calyx of Korla Fragrant Pear and content of IAA、GA3and ABA in calyx and core of young fruits is close:the high content of IAA and GA3and high radio of IAA/ABA、GA3/ABA and (IAA+GA3)/ABA are better to calyx persistent, otherwise benefit calyx fall off.