Analysis On The Differences Of Endogenous Hormone Contents In Different Parts Of Flower And Young Fruit Of Korla Fragrant Pear

Korla fragrant pear(Pyrus sinkiangensis Yu), which belongs to rosaceae, is one of the famous native fruits of Xin Jiang. It is mainly produced in Korla and the surrounding areas, and its fruit is favored by consumers all around the world for the crispness, sweetness, juiciness and rich nutrition, especially for the unique fragrance. In the natural growth situations, the fruit calyx has two states, persistence and shedding. When the fruit calyx is in the state of persistence, the quality of pear will decline, which seriously affects its commodity value.Therefore, Korla fragrant pear, Yali pear and Jinfeng pear which all grow in the natural conditions were chosen as materials in this experiment. Firstly, by using enzyme-linked immunosorbent assay, endogenous hormones(IAA, ABA, GA3 and ZR) were determined in the floral organs of Korla fragrant pear and Yali pear and in different parts of the young fruits of the three cultivars during the using developing progress. Then, through difference analysis, the relationship between endogenous hormone contents and shedding of Korla fragrant pear were explored. From this experiment, it could be expected that the calyx shedding mechanism during fruit development was further ascertained, providing theoreti cal basis for the improvement of calyx shedding rate by artificial intervention of endogenous hormone distribution. Through the experiments, it can be concluded as follows:1. The calyx dropping rate of the first florescence is 20.92%, and that of the fourth florescence is 71.13%, which might be related to the distribution of endogenous hormones. Besides, the distributions of IAA, ZR, GA3 and ABA in different florescence organs were different and they participate in the shedding of calyx as soon as the flower began to bloom.2. High levels of IAA, ZR and GA3 in the upper and lower ovary could cause the persistence of fruit calyx,and high levels of IAA and ZR in the lower ovary have significant effects on the fruit calyx persistence. Moreover, high levels of GA3 in the upper ovary will suppress the shedding of fruit calyx in coordination with IAA, and the increasing accumulation of ABA in the ovary could contribute to the shedding of fruit calyx.3. Significant differences of IAA, GA3, ZR and ABA contents exist in the young fruits during the critical period of the fruit calyx shedding, high contents of IAA and ZRin the middle and lower parts of the young fruits are conducive to the fruit calyx persistence, and the accumulation of GA3 in the young fruits is helpful to the fruit calyx shedding. Further more, ABA in the fragrant pear and Yali pearmainly concentrate on the top of the fruits, and the high content of ABA on the top of the young fruits is useful for the shedding of fruit calyx.4. Artificial intervention could be carried out in the accumulation and distribution of endogenous hormones during the flowering period, and appropriate plant growth regulator could be used in the interference of endogenous hormone distribution to improve the calyx shedding rate of Korla fragrant pear.