Breeding For New Seedless Grapevine Germplasm With Flavor Using Embryo Rescue

Seedless grapevine breeding is one of the most important breeding aims.Excellent characteristics,including seedlessness,flavor,big berry,different maturity stages and high resistance have become ideal breeding goal.Compared with traditional breeding method,embryo rescue technique using seedless grapevine cultivars as female parent could improve seedless rate and shorten breeding time,which is main technique of breeding new seedless grapevine germplasm.To obtain flavorful seedless grapevine,12 cross combinations were designed for embryo technique,covering 8 seedless female parents and 6 male parent with aromatic flavour.Moreover,factors related to embryo rescue rate and changes of endogenous hormone in young ovule abortion were studied,to illustrate the effect of endogenous hormone on embryo development and improve embryo rescue rate.Main results were as follows:1.After pollination and fertilization among 12 cross combinations,7932 ovules were collected and cultured in vitro.914 embryos were obtained with 11.52% of the developed embryo rate,and 391 hybrid seedlings were also obtained with 4.93% of the seedling rate.323 seedlings were domesticated in phytotron,244 of them were transplanted into field,and 190 of them survived,the survival rate 58.82%.2.Two kinds of genetic molecular markers GLSP1-569 and SCF27-2000 were selected for detecting seedlessness among 72 of the cross parents and some of hybrid progenies.The result showed 46 hybrid strains had seedless gene.3.In our study,three seedless cultivars('Ruby Seedless','Flame Seedless' and 'Kunxiang Seedless')were more suitable as female parent in embryo rescue,because of higher seedling rate.'Ruby Seedless' was the optimal femal parent because of the highest seedling rate(14.63%).'Muscat' was the most suitable male parent for breeding flavor seedless grapevines.4.According to the highest embryo development rate and seedling rate,the optimal sampling times were on 43 days and 51 days after pollination(DAP),for 'Flame Seedless' and 'Kunxiang Seedless' as female parent,respectively.For Ruby Seedless × Muscat,Melissa Seedless × Muscat and Perlette × Muscat,the suitable sampling times were at 59~60 days,54 days and 52 days after pollination(DAP),respectively.Embryo abortion time of Crimson seedless × Muscat kyoho and Fantasy seedless × Kunxiang Seedless were considered on 39 days and 48 days after pollination(DAP),respectively.5.For the two seedless cultivars,'Flame Seedless' and 'Neptune',the embryo abortion times were on 41 and 39 days after flower,respectively,based on endogenous hormone changes,fresh weigh changes of berry and ovule as well as embryo rescue rate.