ADVANCES IN EMBRYO DEVELOPMENT OF CHINESE JUJUBE (ZIZIPHUS JUJUBE MILL.)

Chinese jujube (Ziziphus jujube Mill.) is a fruit tree with serious embryo abortion. Midway abortion of embryo is its common phenomenon, which has badly restricted the process of cross breeding work. A number of basic researches on embryology of Chinese jujube has been done. The major advances in embryo development of Chinese jujube are summarized, including gametophyte development, pollination and fertilization, development of embryo and endosperm, the fruiting and seed-setting characteristics and abortion situation of different cultivars，and the mechanism of embryo abortion. Then problems existing in the process of pollination and fertilization, development of embryo, the mechanism of embryo abortion, and embryo rescue techniques are pointed out. Furthermore, it is also proposed that the further research work should focus on the process of pollination, fertilization, impact of physiological character, endosperm nutrition and hormone level on embryo abortion in different developmental stages and cultivars, and delay embryo abortion techniques especially for immature embryos younger than 30 d, in order to promote the cross breeding, to research the mechanism of embryo abortion, germplasm innovations, etc.