| Seedless grapes are one of the principle objectives of grape breeding in the world. Zygotic embryos of seedless grapes can't develop normal seeds because of abortion, so seedless grape cultivars are only taken as paternal parents in breeding new seedless grapes by conventional crossing, but the seedless progeny is only 0 to 15.9%. By embryo rescue technique, seedless×seedless crosses have produced 45% to 82% seedless offspring, but most of them are susceptible to diseases. Hybridization of seedless grapes and V. rotundifolia are performed by embryo rescue, but having a crossing barrier. The wild grapes whose origin of species in China are not only resistant to diseases but also easy to cross with V. vinifera. With the embryo rescue technique coming, it is a feasible way to cross between the seedless grapes (V. vinifera) and Chinese Wild Vitis in order to breed new seedless grape cultivars which are resistant to diseases. 38 interspecific crosses and 13 crosses of V. vinifera have been obtained by artificial pollination in the vineyard in this study. The embryo rescue technique was studied by using 19 crosses as materials that were taking the seedless grapes as maternal parents. The main results were as follows: 1. 2998 new grape seedlings of 51 crosses were obtained, including 2184 seedlings of 32 crosses by normal cross breeding and 814 grapes by embryo rescue breeding. In all of them, the seedlings from crosses between Chinese Wild Vitis (or hybrids) and seedless grapes were respectively 1606 of 20 crosses by pollinations and 257 grapes of 13 crosses through embryo rescue. 2. The optimum medium and the best suitable cultural way were obtained for abortive embryos development of diseases resistance seedless grapes. It was MM3+10mmol/L Gly under the solid and liquid dual layers medium. And the best seedless maternal parents of V. vinifera for embryo rescue were 'Olmo seedless', 'Delight', and 'Flame seedless'. It could improve the embryo development ratio to 66.67%, the ratio of seedling emergence to 64.58%. The optimum medium for somatic embryogenesis was obtained. It was ER (solid medium)+1.0umol/L BA. The somatic embryos coming from zygotic embryos of 'Delight'×'Beichun 'were induced to 82.61% cultured on this medium. 3. Transplanting technique for grape seedlings by embryo rescue has been found in this research. Strong seedlings were selected in spring, then the seedlings were domesticated for 1 week in Erenmeyer flasks under intense light. The next stage was to transplant into pots filled pearlite to domesticate in culture house, in this stage the seedlings must be held moisture, sterilized and sprinkled nutrient solution. And then domesticated into nutrient soil in glasshouse. Finally the plants were transplanted into fields. 4. RAPD analysis was performed using 25 10-mer primers in 6 parent pairs, in order to find specific primers, which could amplify polymorphic fragments in paternal parent. Finally, 7 specific primers(S76,S111,S117,S183,S238,S264,S449) were obtained which could be used to differentiate the parents. In all of them, S183 and S238 were able to select true hybrids. 105 true hybrids coming from seedless cultivars (V. vinifera) ×Chinese wild Vitis(or its hybrid) by embryo rescue were selected by using both morphological characterization and RAPD analysis. The system of marker-assisted breeding for grapes was established. 202 embryo rescue seedlings were chose by both morphological characterization and marker-assisted breeding. 23 seedless grapes resistance to anthracnose, 16 seedless grapes resistance to dowdy mildew and 10 seedless grapes resistance to both diseases were selected. 5. The breeding techniques for seedless grape resistant to disease including pollination technique in fields, embryo rescue breeding technique and marker-assisted breeding technique were selected. A new seedless cultivar 00-3-1 with resistance to disease and a new seedless cultivar 00-2-7 were bred by using these techniques. |
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