关键词: 无核葡萄, 抗寒性, 胚挽救, 新种质, 分子标记辅助选择

Abstract:

【Background】The traditional methods of breeding seedless grape can only use the seeded variety as the female parent and the seedless variety as the male parent to cross, and the rate of the seedless hybrid is extremely low. As a new breeding technology, the embryo rescue can use seedless grapes as female parents, which expands the selection range of female parents, and greatly improves the efficiency of seedless grape breeding. However, the embryo development rate, germination rate and seedling formation rate in seedless grape embryo rescue are still low, which restricts the application of this technique. 【Objective】The main objective of this paper was to screen suitable female parents and embryo development medium for embryo rescue, and to create new cold-resistant seedless grape germplasm by embryo rescue and molecular marker assisted-selection, so as to provide a basis for improving the effect of seedless grape embryo rescue and for further breeding new cold-resistant seedless grape varieties. 【Method】Using the cold-resistant seedless grape cultivar Jupiter (Euro-American hybrid) and the seeded hybrid 00-1-5 ( V. vinifera × V. amurensis) as the male parents and five seedless grape cvs. (Ruby Seedless, Qinhong No.1, Qinhong No.2, Crimson Seedless and Qinxiu) as the female parents, respectively, the hybridization was carried out between seedless grape and cold-resistant grape. The immature fruits of each female parent at the suitable sampling time were collected for ovule culture in vitro. The solid-liquid biphasic MM3 and ER medium were used as the embryo development medium to compare the effects of different medium and female parents on the rate of embryo development, germination, normal seedlings and abnormal seedlings. WPM + 0.2 mg?L^-1 6-BA + 0.1 mg?L^-1 IAA solid medium was used as embryo germination and seedling formation medium. The embryo-rescue seedlings obtained after domestication in the greenhouse were transplanted to the field in spring. In addition, 2MS + 0.2 mg?L^-1 6-BA + 0.1 mg?L^-1 IAA medium was used for transforming deformed seedlings into normal seedlings, which was added with 0, 1.0 and 1.6 mg?L^-1 ZnSO₄, respectively. Finally, the molecular marker SCF27-2000 linked to the seedless gene was employed to detect the seedless hybrids for embryo-rescue seedlings. 【Result】For five cross combinations, 175 embryos from 2 158 ovules cultured in MM3 were obtained, which were further germinated and formed 118 hybrid plants. 74 embryos from 894 ovules cultured in ER medium were obtained and further germinated and formed 58 hybrid plants. Using 00-1-5 as male parent, seedless cv. Qinhong No.2 was much more suitable to be the female parent than Qinxiu, its embryo development rate and seedling rate were the highest, reaching 17.04 % and 7.41%, respectively. Using Jupiter as the male parent, Ruby Seedless × Jupiter had the best effect, with embryo development and seedling rate of 13.71% and 10.67%; the next was Qinhong No.1 × Jupiter, the embryo development rate and seedling rate were 14.39% and 4.71%, respectively. However, Crimson Seedless × Jupiter had the lowest embryo development rate and seedling rate, reached to 9.55% and 1.76%, respectively. The rates of embryo development and seedling formation of ovules inoculated into the MM3 medium were higher than that of the ER medium. The highest rate of deformed seedlings was Qinhong No.1 × Jupiter, while Ruby Seedless × Jupiter had no deformed seedlings. The rate of deformed seedlings in the ER medium was higher than that in the MM3 medium. The deformed seedlings of combination Qinhong No.2 × 00-1-5 were transformed to 2MS+1.6 mg?L^-1 ZnSO₄+0.2 mg?L^-1 6-BA+0.1 mg?L^-1 IAA, producing the best results with a conversion rate of 40.00%. Using the molecular marker SCF27-2000 linked to seedless character, 176 hybrid strains from 5 cross combinations were detected and there were 159 strains with the seedless molecular markers. 【Conclusion】 Ruby Seedless, Qinhong No.1 and Qinhong No.2 were suitable as the seedless female parents for embryo rescue in vitro, but Crimson Seedless and Qinxiu were not relevant. MM3 medium was more appropriate for embryo rescue in vitro than the ER medium. The 159 plants from embryo rescue with the molecular marker linked to the seedless gene were potential seedless hybrids.

Key words: seedless grape, cold-resistance, embryo rescue, new germplasm, molecular marker- assisted selection