| The yield and quality of alfalfa hay are low, and the number of improved varieties is few in our country now. This thing cannot meet the market demand for alfalfa, so it is the imperative thing for us to breed superior alfalfa varieties and improve the yield and quality. Multifoliolate alfalfa has the potential to improve the yield and quality of alfalfa, so many researchers aim at multifoliate trait of alfalfa. In order to study the genetic characteristics of multifoliate trait and the population structure of F1, the PL34HQ of multifoliolate alfalfa and the Huaiyin alfalfa of trifoliolate were used to hybrid by artificial pollination, then the F1population was gotten.180plants of Flwere used to analysis the agronomic and economic characters and the genetic diversity and population structure were also analyzed from molecular way,and the purpuse was to understand the genetic characteristics of multifoliate trait, chose some exllcent plants for breeding besides. The results are follows:1. The group multifoliolate rate of Fl population was91.11%, the maximum multifoliolate rate o f the plants with multifoliolate trait was93.33%, and the minimum was1.64%,39.8%was the average. Group multifoliolate rate of Fl population in spring and autumn was higher than summer and winter.2. There were three colors of the stem of Fl plants, purple stems, green stem and purple-green stem, and the proportion of them was nearly1:1:1. The purple-green stem plants showed higher production performance.3. The order of correlation coefficient of other traits to the yield trait was branches>height> multifoliolate rate>stem/leaf ratio. Fresh weight was significantly correlated with the number of branches and plant height. Multifoliolate rate was negative correlated with height and stem/leaf ratio, but not significant; and was not significantly correlated with branches. At last, branches were not significantly with stem/leaf ratio. 4. There were19pairs of primer with better polymorphism filtered from161pairs of SSR primer and18pairs of EST-SSR primer, and the19pairs of primer were used to test F1population. A total of79allelic variation was detected, and4.16to per primer. Primer MtB8and MtB218had the most allelic variation, the value was eight; MES58and MES64had the least, and the value was one. The average ratio of polymorphism was61.58%, and the gene diversity was0.2188, the average PIC was0.7603.5. F1population was divided into four groups by genetic structure analysis. When the Q value was over0.5, the plants were set into appointed groups. And the plants number was145(80.56%). As to the145plants,18.89%was in group1,25.56%was in group2,18.33%was in group3and17.78%was in group4. The results of genetic diversity of the cluster analysis showed that highest genetic diversity in Group2, followed by Group1and group4, group3was the lowest levels of genetic diversity.6. There was a large difference in multifoliolate rate, fresh weight and dry weight of the four groups, but no significant difference in plant height, number of branches and stem/leaf ratio. Group4had the highest multifoliolate rate, group3was at lowest, and the difference was significant. Group1had the maximum fresh weight and dry weight, group3was at lowest with the significant difference. As far as the overall levels, group3showed a poor character, and the other3groups had its own advantages in plant height, number of branches, multifoliolate rate, stem/leaf ratio, fresh weight and dry weight, at last, the comprehensive level of group1was better. |
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