| Four excellent cultivars of Chinese jujube, including Dongzao, Jisifeng, Wudeng and Fuzao ,were employed to establish the optimized system of embryo culture in this paper. According to the growing characters of embryo, 6 growing periods of fruits were selected to carry on embryo culture: For clearing the characters and mechanism of embryo abortion, the endogenous hormones of pulp and seed on Dongzao and Lizao were determined and the conditions of embryo abortion about 28 cultivars were also observed. The main results are summarized as follows:1 The optimized model of embryo culture on Chinese jujube was established firstly by comparing and selecting the culture medium and conditions systematically. The method of two-step culture was applied. The embryo of different growing periods were cultured in germination medium firstly: Younger embryo should on MS+BAo.i~o.5mg/L+ IBAo.s-i.omg/L + NAAo.img/L+sucrosesog/L+agaryg/L+LHsoomg/L, older embryo should on this medium without plant growth regulars. Afterward the regeneratedplantlet were transferred to growing medium: MS+sucrose30g/L+agar5g/L. If many embryoid and adventious buds were emerged on cotylendons or embryonic axis of embryo, it was still cultured in germination medium, which would be added to a little liquid medium, to induce regenerated plantlet.2 There were three growth-style after Chinese jujube embryo plant on the medium: For very young embryo (less than 30 days after fruit set ), added to osmotic pressure of medium > LH and husk of seed45inhibition to make embryo continue growth and development; the younger embryo, the easier was the formation of callus; the rate of formation of callus desended when embryo approached ripe gradually, but plantlet easier.3 Those conclusion were presented in this paper: (l)the age of embryo were thought as the key factors in embryo culture; (2)BA of low level and IBA of high level were beneficial to germination and inducing plantlet from embryoid and adventious buds;(3)Low temperature treatment(2~4'C ,44d)beneficial to plantlet forming by embryo at 55d after set fruit, but it affected the quality of plantlet;(4)the quality of regenerated plantlet could be improved by using optimized measures;(5)7~10d of dark treatment was beneficial to rooting on the inoculated embryo(6)A proper quantity of LH was helpful to embryo germination.4 The measure of plantlet making better: Firstly selecting the earlier fruit and fruit of embryo growth-style normoally; Secondly adopting to two-step-culturing method, plantlet should transfer to high osmotic pressure medium with LH and without plant growth substance, afterwards transfer to growing medium; Thirdly, root tip wope out, the plantlet took root more easly.5 The kernel rate and the condition of embryo abortion about 26 excellent cultivars of Chinese jujube were survived on hard kernel stage .The result found that the size of fruits was important to the kernel rate and embryo abortion. The kernel rate If big fruits were higher signfixabtly than small ones. Most aborted cultivars usually aborted on the initial phase of growth .The kernel rate of 471 cultivars were widely different.6 The endogenous hormones of seeds on Lizao and Dongzao were determined by HPLC. The result showed that Zeatin content of seed of and pulp of Lizao reached climax at the initial phase of fruit development, but low in pulp of Dongzao; the content of GAs in the Dongzao'seed maintained at low level continuosly. The content of46endogenous hormones in the pulp of Dongzaoand Lizao was different, both desended low level at the phase of kernel. The cintent of IAA in the pulp of Lizao was higher than Dongzao, but content of IAA in the Dongzao seed maitain high level continuously. The content of ABA in all these were found after 40 days after fruit set, then ascend continuously afterwards. The content of GAa and IAA in the pulpof lizao seedless fruit was higher than seed fruit. lizao We can conclude: I. The pul...
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