Study On The Characteristics Of Fruiting And Fertility For Ziziphus Jujuba Mill.

Physiological abscission during jujube development, fruiting ability and fertility under self-pollination and natural pollination were studied in the paper. And the results were as follows:1 Average fruit percentage after first physiological abscission of 280 cultivars was only 3.51% and 50.62% fruits abscised before harvesting because of lacking of nutrition. Fruit percentage of total flowers before harvesting was 1.48%.2 Fruit percentage after the first physiological abscission was significantly correlated with percentage of abscised fruit before harvesting and fruit percentage of total flowers. Fruit percentage after the first physiological abscission was significantly negative correlated with percentage of kernel; Percentage of abscised fruit before harvesting was significantly negative correlated with fruit percentage of total flowers; Fruit percentage of total flowers was significantly negative correlated with percentage of kernel.3 Theaverage percentage of fruits to bearing shoots(PFTBS) under natural pollination was also significantly higher than that under self-pollination after the first physiological abscission. The average PFTBS under natural pollination was significantly higher than that under self-pollination before fruit harvesting in Shanxi(National Jujube Repository) cultivars. However, it didn't show significantly difference in cultivars of Jujube Repository in Cangxian County.4 The average percentage of fruits with seeds(PFWS) under natural pollination were also higher than that under self-pollination in both Shanxi cultivars and Cangxian cultivars and PFWS under both self- and natural pollinationo of Cangxian cultivars were also smaller than that in Shanxi cultivars. But the differences were not significant.5 All the tested cultivars could be devided into five groups, i.e. self-fruitless and natural-sterility, self-fruitless and natural-fertility, sterility under both self and natural pollination, self-sterility and natural-fertility, fertility under both self and natural pollination. The five groups counted for 11.07%, 16.79%, 44.64%, 16.07% and 11.43%, respectively. Seven cultivars with plump seeds under natural polllination together with stable characteristics of self-fruitless or natural-sterility were selected to be further used in jujube cross breeding for their advantages of omitting stamen removing. They were Xiaodundunzao, Xiaozao 4, Xiaozao 25, Hongzhaoshiyuehongzao, Guangdongbaizao, Daliyuanzao and Yuanlingzao.6 Fruiting ability and fertility changed with cultivars, strains, years, geographical conditions and orientation of the canopy, among which cultivar was the most dorminent factor; The fruiting ability was more changeable and the fertility showed much more stable; In terms of PFTBS, only 4.17% and 15.38% of the cultivars kept stable between years and geographical conditions respectively, while in case of PFWS, 64.58% and 73.08% kept stable; The PFTBS under self-pollination was much higher in the south-west and north-west parts of the canopy than that in other orientations.7 Low concentration of GA3 (0-10 mg/L) could enhance the PFTBS and decrease PFWS. However, the PFTBS decreased when GA3 concentration reached 35mg/L. And 150mg/L 6-BA,0.02g/L amino acid fertilizer could decrease both PFTBS and PFWS after natural and self-pollination.8 PFTBS under self-pollination was significantly correlated with that under natural pollination. PFWS under self-pollination was significantly correlated with that under natural pollination. PFTBS under self-pollination was significantly negative correlated with PFWS under natural pollination. PFTBS under natural pollination was significantly negative correlated with PFWS under natural pollination.9 PFTBS under self-pollination, PFTBS under natural-pollination, PFWS under self-pollination and PFWS under natural-pollination all did not follow normal distribution. Self-sterility was the basic type of Chinese jujube cultivar and it could be transform with self-fruitless and self-fertility each other. However, transform seldom happed between self-fertility and self-fruitless.