The Study On The Technique Of Ovule Culture Of Grapes And Triploid Seedless Grape Breeding

35~60days after florescence , ovules of Kyoho (v. vinifera ×v. labrusce cv.), Rizamat (v. vinifera cv.) , Thompson Seedless (v. vinifera cv. Sultanina), grapes were cultured on MS medium supplemented with different growth regulators in order to study the techniques of ovule culture and triploid grape breeding. The results indicated that the best period of inoculation of Kyoho and Rizamat was 60 days after blossom. We obtained 96% development rate (p<0.01) and 37.5% germinate rate (p<0.01)of Kyoho's ovules in Ⅶ medium, and 76% development rate (p<0.01) and 63.5% germinate rate (p<0.01) of Rizamat's ovules in the Ⅴmedium. But the best effect was obtained from 50 days after florescence of inoculation of Thompson Seedless' embryo. We got 44% development rate and 31.9% germinate rate (p<0.01) of Thompson Seedless' ovules in Ⅶ medium.Reciprocal crossing was made between the diploid grape varieties (Rizamat and Thompson Seedless) and the tetraploid grape cultivar (Kyoho) in order to obtain the new triploid grape variety of huge and seedless fruit. 42 hybrid triploid plants were derived by means of in vitro ovule culture in early fruit development period (45~60 days after pollination). Ovule culture-derived plants have been established for progeny test in our laboratory. We reproduced 32 hybrid seedling to more than 300. Root tip cells of plantlets derived from diploid × tetraploid grapes had 57 chromosomes. The test demonstrated that the difference of the period of ovule-abortion and the sensitive degree supplemented with different growth regulators was great. Kyoho ×Rizamat ovules, from 45~55 days after anthesis, were cultured on Ⅸ medium, giving the best percentage of established plants per development embryo 20%. Rizamat×kyoho ovules, from 55~60 days after anthesis, , were cultured on Ⅴ medium, giving the best percentage of established plants per development embryo 20%. Kyoho × Thompson Seedless ovules, from 50~55 days after anthesis, were cultured on Ⅶ medium, giving the best percentage of established plants per development embryo 38.9%.The research demonstrated that above 90% brown ovules were living (development embryo), and above 95% green ovules were abortive. The test indicated that tetraploid cultivars ass female parent is easier to obtain hybrid progeny than that of diploid ones in triploid seedless grape breeding. Cold treatment and cutting cultured ovules of Kyoho and Rizamat raised the percentages of embryo germination and plant formation 45% and 30% respectively.