The Style Types And Segregation Of Fecundity And SSR Molecular Marker About The Hybrids From The Self-fertile Common Buckwheat

Common buckwheat has self-incompatibility, and its setting percentage is below 15%.The low seed setting rate severely restricts improving the yield of common buckwheat,thereby reducing the enthusiasm of private to cultivate common buckwheat. Homostylic common buckwheat has self-compatibility, and its fecundity is better than common buckwheat under natural conditions. So it can sharply increase the yield of common buckwheat if the homostylic common buckwheat is used for improving common buckwheat breed. In this study, we focus on the hybrids of F3 and F4 which date from hybridization between common buckwheat and homostylic common buckwheat, and investigate the segregated types and segregated rate of style character in the 13 common buckwheat lines.And we conduct the SSR molecular marker analysis aiming at various style types of the hybrids from the same crossing combination. In this study, the results show that as follows.(1) The style of common buckwheat are isolated five types in the F3 hybrids and F4 hybrids, and the five style types are homostylic type, pin type, thrum type, short pin type and long thrum type. Statistics and analysis showed that the largest proportion of the separation of the styles in the hybrids of F3 and F4 generations is homostylic type which is 45%. Both of the separation ratios of long thrum type and pin type are higher, 26% and 19% respectively. The separation ratio of short pin type is 8% which is lower, and the ratio of thrum type is only 2%which is lowest.(2) We adopt the method of averaging the setting percentages of three parts which include the upper, middle and lower inflorescence to determine the self-fertility percentage of common buckwheat. In an isolated environment, the self-fertility percentage of homostylic type in the net room and greenhouse are respectively about 47.9% and 17.2% which are highest. The long thrum type are respectively about 25.6% and 8.6% which are higher. The short pin type are respectively only 12.8% and 2.6% which are lower. Both of the self-fertility percentage of pin type and thrum type are lowest and they are basically self-incompatible.(3) Through investigating, we found that the yield of per plant of homostylic type is significantly highest, and the long thrum type is higher, but all of short pin type, pin type andthrum type are lower. There exist significantly difference about the yield and seed number of single plant among the 5 style types.(4) We conduct the SSR molecular marker analysis aiming at 5 style types of the hybrids from the same crossing combination taking advantage of 21 pairs of SSR primers. In this study, we screen for 11 pairs of primers which show abundant polymorphism, and we found that the SSR markers of thrum type are clear in this study. We can identify and discriminate the 5 style types using primers of Fes2328, BM87 and Fes2695 in this study.(5) There exist significantly difference about the segregation ratio, yield and seed number of single plant among the 5 style types, and exist obvious difference on the molecular marker. So the five style types are at different levels respectively. It shows significantly positive correlation between style types and self-fertility and show very significantly positive correlations among setting percentage, yield and seed number of self-fertility of single plant.In the generations of F3 and F4, the segregation ratio of homostylic type is largest and its self-fertility percentage is significantly highest, so it is significant to increase yield of common buckwheat if the homostylic type is purified in the generations.