Efects Of CPPU And Ethephon On Growth And Development Of Muskmelon

In the first study,we analyzed the effects of ethephon on the first female flower node, number of female flowers,fruit characters and endogenous hormone concentration in the young leaves by sparying different concentrations of ethephon to seedlings of"Shannong Jinhuang 1 Muskmelon"。The results provide a theoretical basis for the reasonable application of ethephon in muskmelon production。In the second study,we analyzed the effects of CPPU on fruit set, fruit growth, endogenous hormone concentrationin and fruit quality by spraying different concentrations of CPPU to the ovary of"Shannong Jinhuang 1 Muskmelon"in the flowering stage。The results provide a theoretical basis for the reasonable application of CPPU in melon production and solutions for enhancing the fruit set under the unfavorable conditions for pollination and fertilisation,and we also studied the mechanism of effects of CPPU on fruit growth by analyzing the endogenous hormone concentration in the fruits。Main results are as follows:1. Ethephon could significantly debase the first female flower node and increase the number of the female flowers within from the eighth to the thirteenth node。The appropriate concentration ethephon could increase the fruit weight,soluble solids and soluble sugar contents。IAA and GA3 contents in the young leaves in muskmelon were obviously reduced along with the increase of the ethephon concentration,in contrast,ABA content increased as ethephon concentration increasing,these data suggested that the exogenous ethephon could inhibit the synthesis of IAA and GA3,but promote ABA synthesis in the young leaves in muskmelon。Ethephon can significantly affect the sex differentiation of muskmelon and improve the fruit quality;The effect of ethephon on the female flower differentiation may be caused by affect of ethephon on the enogenous hormones contents。2.CPPU could significantly enhanced fruit set of pollinated plants(100%,Control 82%),and fruit set of unpollinated plants also also reached 100%, so we successfully inducted parthenocarpy of muskmelon by using CPPU。CPPU could significantly improved growth of pollinated fruits and parthenocarpic fruits, enhanced fruit weight。CPPU could significantly improve soluble sugar and vitamin C content of pollinated fruit。However, soluble sugar and vitamin C contents in the parthenocarpic fruits were lower than control fruits。Effect of CPPU on fruit flavor was also siganificant。The results showed that 20mg/L is the most appropriate concentration for muskmelon in our study。3.CPPU could increase endogenous IAA and GA3 concentrations of the pollinated fruits, reduce endogenous ABA content of the pollinated fruits, which might be the main reason for faster fruit growth。But endogenous IAA and GA3 contents of the parthenocarpic fruits were lower than these of the control fruits, so we guessed CPPU induct parthenocarpy of muskmelon not by increasing endogenous IAA and GA3 contents, but played direct function of cytokinin。CPPU may inhibit the synthesis of endogenous Zt, so endogenous Zt content declined。...