| Seedless grape is an important development direction for production and consumption of the grapes around the world, and it is an aim for the breeding experts to obtain many new cultivars with good-quality and disease resistance. For the fertilized embryos often aborted during their development in the stenospermocarpy grapes, the conventional strategies only could adopt seeded×seedless method with a long breeding cycle. Whereas, the development of embryo rescue makes stenospermocarpy grapes serve as the female parents directly, reducing the breeding cycle efficiently and raising the percentage of seedless hybridizations. It is well known that most of the European seedless cultivars (Vitis vinifera) are susceptible to fungul diseases, and Chinese wild Vitis are abundant disease resistant grape germplasms, more compatible to Vitis vinifera compared to Vitis rotundifolia. So embryo rescue, combining the good quality of the European stenospermocarpy grapes with the disease resistance of Chinese wild Vitis, is an effective way to seedless grape breeding and new germplasm innovation.In this research, seedless grapes breeding with the European stenospermocarpy grapes and Chinese wild Vitis as the parents, polyploidy grapes breeding with the European stenospermocarpy grapes, Euramerican tetraploid cultivars and Beichun(V.amurensis×V.vinifera)as the parents and some influent factors were studied by using embryo rescue of 19 crossings. An improvement of seedless grapes breeding by embryo rescue was developed and a successful polyploidy grapes breeding system comprised of traditional crossing, ovule culture, flow cytometry and chromosome identification was obtained. The main results are in the following:1. The influence of different phytohormones, low tempreture treatment, antioxidant treatment and parental compatibility of different polyploidy on embryo germination was investigated during in-ovule embryo culture. It showed that using IAA can improve the percentage of embryo germination, more effective than using IBA , and 1.5mg/L IAA was better than 0.75mg/L IAA; More embryo germination were obtained through 5-8℃treatment on fruits for 30 days before ovules dissection than through 30 days 5-8℃treatment on ovules after dissected; different antioxidants treatment had different effects on embryo germination, and vitamine C had less antioxid effect than active carbon; the order of parental compatibility, according to percentages of embryo germination, was tetraploid seeded grapes×diploid seeded grapes> diploid seedless grapes×diploid seeded grapes > diploid seedless grapes×tetraploid seeded grapes.2. 106 hybrid progenies were obtained by embryo rescue from night hybrid combinations and three self-pollination combinations. 42 clones from the crossings among Delight×Xuefeng, Thompson seedless×Beichun, Ruby Seedless×Shuangyou were tested with a SCAR marker of the seedlessness gene, and the results indicated that 23 of them were found to have the special marker, so the percentage of the seedless grapes was 54.8%, more than the traditional breeding.3. 42 hybrid seedlings were obtained by embryo rescue from seven combinations among Ruby Seedless×Fujiminori, Dawn Seedless×Fujiminor, Emerald Seedless×Black Olimpia, Delight×Black Olimpia, Dalihong Seedless×Fujiminori, Fujiminori×Beichun and Black Olimpia×Beichun. All the hybrid progenies were determined by flow cytometry, and further determined by chromosome identification on the results from flow cytometry. The results showed that the hybrid progenies were made up of 11 triploid, 6 tetraploid, 4 aneuploid and 21 diploid. It provided novel grapevine germplasm for seedless grape breeding and a successful polyploidy grapes breeding system.4. According to the rescued seedlings transplanting system from the former researches, 176 seedlings from seven crossing were transplanted, and 154 seedlings were survivable as the percentage of seedlings survival was 87.5% on average. |
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