Development Of Novel Muscat Seedless Grapevine Germplasm By Embryo Rescue

Seedless grape were favored by consumers around the world due to its convenience. In the field of seedless grape breeding, conventional crossing could only use seedless cultivars as male parent and seeded cultivars as female parent. However, in this way the seedless rate in progenies is very low. Now the breeders can use seedless cultivars as female parent with the embryo rescue technology. With this method not only expanded the parental choice but increased the rate of seedless progenies.In this study, several stenospermocarpic seedless grapes were used as maternal parent, 16 hybrid combinations were designed. These hybrids were used to improve the technique of embryo rescue during embryos germination and development. The main results as following:1.Different crossing parents influenced embryos germination rate and seedling rate. When we chose Aishenmeigui, Ruby Seedless and Sultanina Rose as female parents, the rate of germination were 13.27%, 10.15% and 11.89%, the seedling rate were 57.51%, 50.76% and 57.64%, higher than other cultivars. When used Blush Seedless and Delight as female parents, the rate of germination were 4.37% and 3.34%. And the seedling rate was 11.11% when used Jupiter as female parent. They were very low. Same female parent but different male parents also can influence the embryo rescue efficiency. When chose Ruby Seedless as female parent, both Flame Seedless and Zixiang Seedless were better than as male parent. The germination rate and seedling rate were 10.15%, 14.36% and 51.52%, 37.51%. But there was no significant difference of embryo germination efficiency between Sultanina Rose× Zixiang Seedless and Sultanina Rose× Shuangyou(V. amurensis Rupr.) and we can saw the same result between the combinations of Crimson Seedless× Aishenmeigui and Crimson Seedless× Taishan-2(V. bryoniifolia Bunge.). These results suggested that female Parents play a key role on the efficiency of embryo rescue.2. The suitable sampling time of Neptune× Beauty Seedless was 36 DAF, and the suitable sampling time of Ruby Seedless× Flame Seedless was 44 DAF. We got the best result of embryo rescue during this period of sampling.3. The effects of exogenous application of polyamine(PA) on embryo development. The optimum concentration of putrescine(Put), spermidine(Spd) and spermine(Spm) at the stage of embryo seedling were determined: 3mmol·l-1 Put increased the rate of seedling in Sultanina Rose× Shuangyou(V. amurensis Rupr.), Ruby Seedless× Zixiang Seedless and Aishenmegui× Shine-Muscat. The seedling rate was increased by 13.34%, 6.67% and 30.16%, respectively. Added 0.5mmol·l-1 Spd raised the seedling rate in Ruby Seedless× Flame Seedless and Blush Seedless× Aishenmeigui. The seedling rate was increased by 15.08% and 5.56%, respectively. 0.3mmol·l-1 Spm raised the seedling rate in Ruby Seedless×Jiangxi-2(V. romanetii Roman. du Caill. ex Planch) and Sultanina Rose× Zixiang Seedless.The seedling rate was increased by 14.76% and 9.52%, respectively.4. A total of 1006 plantlets of 432 lines were obtained and 749 of them were survived. The average survival rate was 74.45% and the highest survival rate was 84.13%.