Study On Self-incompatibility Genotype Of Dounan Apple Cultivar

Apple is a kind of Gametophytic self-incompatible fruit tree, so it is necessary to arrange varieties for pollination or perform artificial pollination for stable yield. Pollination compatibility among cultivars must be considered first before arranging pollen donor, and pollination compatibility is determined by S genotype of the cultivars, when their S genotypes are the same, then exhibitions incompatible, but when their S genotypes are different, and exhibitions compatible. Dounan is a new apple cultivar, but its S genotype is unknown. In this thesis, S genotype of Dounan was studied, so as to provide theory basis for apple production. The results were as follows.1. The pollen germination percentage of the cultivars were up to 73.33 % , so all of them could be used as pollination. The amount of pollen tubes from style bottoms and percentage of style with pollen tubes through their bottoms in semi vitro culture of Dounan styles pollinated with Golden Delicious which showed cross-incompatible was 0.58 and 29.03%, but they were 3.06-4.70 and 77.42%⁸6.67% when Dounan styles were pollinated with Fuji , Indu and Baskatong which showed cross-compatible.The result of pollinated styles in semi vitro culture showed that Dounan contained S₂- or S₃- allele.2. The OD₂₆₀/OD₂₈₀ ratios of different cultivars DNA distilled with improved CTAB method after purified were 1.8¹.9, when detected with agarose gel eletrophoresis, DNA showed a trim bright band without smear, and there was no residue bright in sample hole. The result showed that the DNA purity was high, and without degradation, it was suitable for PCR-RFLP analysis.3. The optimization system of S apple gene PCR amplification was as follows. In 20 μL reaction system, the amount of Taq DNA polymerase was 1 U, dNTPs amount was 0.25 mmol·L^-1, primer amount was 0.4μmol·L^-1, Mg²⁺ concentration was 2.5mmol·L^-1, templet DNA amount was 40ng, and 1 ×Buffer. The amplification program was as follows. 1 cycle of 2min at 94℃, 10 cycles of 15s at 94℃, 30s at 50℃ , 1min at 68℃; 25 cycles of 15s at 94 ℃, 30s at 50 ℃ , 90s at 68 ℃; 1 cycle of 5min at ;-20℃ stored after...