Effects Of Cross-pollination On Endogenous Hormones And Gene Expression Of Related Metabolic Pathways In Guanximiyou’(Citrus Grandis)Juice Sacs

In this study,we conducted self-pollination(control)and cross-pollination of’Guanximiyou’(Citrus grandis)to study the effects of cross-pollination on the quality of the fruit juice sacs,the change of endogenous hormones and the expression of biosynthesis key genes and signals transduction genes of abscisic acid and jasmonic acid in the period of maturity period on 20 August,20 September and 20 October(harvest)and storage period on 20 November,and to explore the mechanism of the pomelo fruit juice sacs granulation and increase by changing hormonal content and related metabolic pathways.The main results are as follows:1.There were a large number of seeds by cross-pollination in a fruit,by which average seeds were above 60 grains,and the seed number was negatively related with the fruit granulation index;The cross-pollination caused a significantly lower fruit granulation index than self-pollination,and improved edible rate、total soluble solids、titratable acid、Vc and water content of the fruit at harvest time,which brought about a increase of the weight,and thus to improve the quality of the fruit.2.Along with the pomelo fruit mature,the ABA content of fruit juice sacs increased,among the cross-pollination decreased ABA content,and had a strong positive correlation with the granulation index.The content of CTK in the fruit juice sacs was decreased,among the CTK content by self-pollination was significantly higher than by cross-pollination,and was positively negative correlated with the granulation index.The content of GA3,SA and JA in the juice sacs were increased by cross-pollination,and had a negative correlation with the granulation index.3.The expression of 13 genes in ABA and JA biosynthesis and signal transduction pathways were analyzed by fluorescence quantitative PCR.Along with the maturation of pomelo fruit,the expression of CrNCED-1,CrZEP-1 and CrSnRK2-1 by cross-pollination were lower by self-pollination in ABA biosynthesis.The expression of CrPP2C-1,CrPP2C-2,CrPP2C-3 and CrABF-1 in four periods were not consistent with the changes of ABA content in self-pollinated and cross-pollinated fruit juice sacs.The expression of CrJAZ-1,CrJAZ-2,CrMYC2-1 and CrMYC2-2 in the cross-pollinated fruit juice sacs were significantly higher than those in the self-pollinated fruit juice sacs in the harvest and storage period.