Creation Of Seedless And Triploid Breeding Materials Of Grape And Evaluation Of Hybridizing Superior Lines

Seedless grape have significant advantages in eating and making raisins,at present,creating new grape varieties is the focus of breeding work.The efficiency of breeding new seedless grape varieties by conventional hybridization is low and the screening period is long,however,using embryo rescue technology to cultivate grape hybrid embryos in vitro,more new hybrid grape lines can be obtained in a short period of time,which not only expands the selection range of hybrid parents,but also improves the breeding efficiency of seedless grape.In this study,we created new seedless breeding materials with embryo rescue technique and hybridization of the stenospermacarpic grapes as female parents and seeded grapes as male parents,use of seedless molecular markers for early identification of hybrid progeny seedless traits.And we created new triploid breeding materials with embryo rescue technique and hybridization of the tetraploid grapes as female parents and diploid grapes as male parents,the technique of preparing grape root tip chromosome section by enzymatic drip method was studied.Furthermore,early evaluation and identification of superior lines from conventional hybrid progenies lay the foundation for further breeding of high quality grape varieties.The major conclusions are listed as below:1.A total of 12 hybrid combinations of seedless × seeded grape were configured with‘Crimson Seedless’,‘Flame Seedless’,‘Ruby Seedless’,‘Sweet Sapphire Grapes’,‘Thompson Seedless’,‘Zicui Seedless’ and ‘Zitian Seedless’ as the female parent,‘Sunshine Muscat’,‘Zuijinxiang’,‘Kyoho’ and ‘Jumeigui’ as the male parent,7066 grape hybrid fruits were obtained,8710 ovulates were inoculated,1290 germinated embryos were obtained,the average embryos development rate was 14.81%,and 620 embryo rescue seedlings were obtained,the average seedling rate was 7.12%.The highest embryo rescue efficiency occur when ‘Ruby Seedless’ and ‘Zitian Seedless’ as the female parents.Through the study of sampling time by stages.When ‘Thompson Seedless’ is taken as the female parent,the best time for embryo rescue is respectively 38 days after pollination(DAP);when ‘Ruby seedless’ is taken as the female parent,the best time for embryo rescue is respectively 54 DAP;the‘Crimson Seedless’ is taken as the female parent,the best time for embryo rescue is respectively 63 DAP;when ‘Zicui Seedless’ is taken as the female parent,the best time for embryo rescue is respectively 40 DAP.620 hybrid lines were screened by GSLP1-569 、SCC8-1018 and SCF27-2000,there were 452 lines that could be preliminarily identified as seedless lines,seedless rate of 72.90%.2.A total of 8 hybrid combinations of tetraploid × diploid varieties were configured with ‘Hutai NO.8’,‘Kyoho’,‘Jumeigui’ and ‘Zuijinxiang’ as the female parent,‘Flame Seedless’,‘Sunshine Muscat’,‘Bixiang Seedless’ and ‘Seedless chilling honey’as the male parent,4048 grape hybrid fruits were obtained,1727 ovules were inoculated,545 germinated embryos were obtained,the average embryos development rate was 31.56%,and 153 embryo rescue seedlings were obtained,the average seedling rate was 8.86%.The higher embryo rescue efficiency occur when ‘Jumeigui’,‘Zuijinxiang’ and ‘Kyoho’ as the female parents.Through the study of sampling time by stages.When ‘Jumeigui’ is taken as the female parent,the best time for embryo rescue is respectively 55 DAP.Preparation of grape root tip chromosome specimens by enzymatic hydrolysis and dropping method.The optimum enzymolysis time of grape root tip was 60 min,and using phase contrast microscope to chromosome observation after production omit the traditional dyeing steps,unfortunately,we can’t see all the chromosomes inside the cell.3.To evaluate and screen F1 generation of conventional hybrid grapes planted in 2017.16 superior lines(3-1-2,3-2-2,3-2-6,4-2-10,4-3-8,4-7-12,6-1-3,6-1-6,6-2-5,6-3-3,8-5-1,8-7-4,13-3-7,21-1-1,21-1-3 and 21-1-7)were obtained.After systematic evaluation and identification of 16 hybrid superior lines,five new strains were finally selected,namely3-2-6(dark-purple pericarp,nearly round fruit,rose fragrance),6-1-3(dark-purple pericarp,round fruit,rose fragrance),6-1-6(purplish red pericarp,macrograin,blunt ovoid fruit,rose fragrance),6-2-5(dark-blue pericarp,round grains,rose fragrance)and 21-1-1(dark-purple pericarp,round grains,rose fragrance),were selected as superior new lines with certain development and promotion value.