Study on dynamic changes and correlation relationship of fruit quality and leaf indexes in pomegranate during fruit development

【Objective】The change trend and correlation relationship of fruit quality and leaf indexes were studied in two pomegranate cultivars during fruit development. The study could provide theoretical basis for the improvement of pomegranate fruit quality.【Methods】The fruit quality and leaf indexes of‘Taishanhong'and‘Taishansanbaitian'pomegranate were investigated by titrimetric method and ultraviolet spectrophotometer during fruit development.【Results】The single fruit weight,soluble solids content,ratio of soluble solids and titratable acid,soluble sugar content of two pomegranate cultivars increased significantly. The content of titratable acid decreased significantly in two pomegranate cultivars. The titratable acid,ratio of soluble solid and titratable acid and soluble sugar were significantly different between two cultivars. The content of vitamin C in cultivars increased gradually with fruit development. The vitamin C content of‘Taishanhong'increased rapidly at the late development stage(September 15),which was higher than that in‘Taishansanbaitian'. The extremely significant difference existed in the vitamin C content of two pomegranate cultivars. The anthocyanin content of‘Taishanhong'increased gradually with fruit development,but increased rapidly at the late stage(after September 5),and was higher than that in‘Taishansanbaitian'. The anthocyanin content of‘Taishansanbaitian'varied within a small range. The peak value of total flavonoids in both two cultivars presented in young fruit(July 15) and maturity(October 5)period. The content of chlorophyll a,chlorophyll b,soluble sugar and total flavonoids in leaf decreased gradually as a whole. But carotenoid content increased gradually at the late fruit development stage. Correlation analysis indicated that the fruit soluble sugar was significantly positive correlated with fruit anthocyanin content. Chlorophyll a and chlorophyll b had significantly positive correlated with leaf anthocyaninand total flavonoids. The correlation between leaf anthocyanin and total flavonoids was significantly positive. The leaf anthocyanin was significantly negative correlated with single fruit weight,fruit soluble solids,ratio of soluble solid and titratable acid and soluble sugar. There was significant negative correlation between leaf total flavonoids and fruit soluble sugar.【Conclusion】There was remarkable difference in fruit quality and leaf indexes between two pomegranate cultivars during fruit development. The increase of fruit soluble sugar was beneficial to fruit anthocyanin synthesis. The synthesis of leaf anthocyanin and total flavonoids were benefited from the increase of chlorophyll content. The correlation degree of fruit quality and leaf indexes existed significant differences in two pomegranate cultivars.