Assessment of factors affecting the in-vitro embryo development of Chinese jujube

Chinese jujube is a fruit-bearing plant with severe early embryo abortion, which has become a major problem in the process of the hybridization breeding. The aim of study is to prolong the development of the immature embryo before abortion and improve the efficiency of immature embryo rescue of Chinese jujube. 20-40 days old embryos of three cultivars of Chinese jujube (Ziziphus jujuba Mill. 'Lengbaiyu', 'Liuyuexian' and 'Xiangfenyuanzao') were used as materials. Effects of cultivars, embryonic age and exogenous hormones on the development of the Chinese jujube were studied. 'Xiangfenyuanzao' showed faster embryo development than 'Lengbaiyu' and 'Liuyuexian'. Immature embryos of 'Lengbaiyu' had higher embryogeny rate than 'Xiangfenyuanzao' and 'Liuyuexian'. Three jujube cultivars and different embryonic age had different responses to the exogenous hormones. The ideal sampling stage of immature embryos for the three cultivars were 30 d of embryonic age, while the embryogenic rate of 'Lengbaiyu', 'Xiangfenyuanzao' and 'Liuyuexian' was 56.82, 54.17 and 52.53% respectively. The results indicated that the embryonic age had the greatest effect on the growth and development of juvenile immature embryos, followed by cultivars, the type of exogenous hormones and the concentration of exogenous hormones, and young embryo developmental stage, the response to the exogenous hormones are different.