Studies On Genetic Diversity Of Alnus Rubra

Bio-diversity is the natural wealth of the world and the foundation of human survial. The genetic diversity is the basis of bio-diversity and the source of genetic improvement. Alnus rubra is a fast-growing nitrogen-fixing species introduced from North America, high economic value, afforestation or cultivation has a long history,the formation of fine lines and corresponding supporting technology, adaptable, can be planted in special legislation on the ground, seedling growth compared with the similar species or varieties increased by 10%.The successful of Alnus rubra's introduction is important for forestation, furniture and paper making. Therefore, the research of Alnus rubra's genetic diversity has important meaning.In this paper,60 individual samples were collected from two cultivated populations located in LiuHe and XiaShu. From the phenotypic and molecular levels to study systematically the variation patterns within and among of Alnus rubra by using variance analysis, UPGMA clustering and RAPD markers, It will lay the foundation of Alnus rubra's breeding and genetic improvement.1. Analysis of phenotypic characteristics of 60 samples from two cultivated populations showed that Alnus rubra had abundant variations. The average coefficients of variation were significantly different in different parts. From highest to lowest:leaf width> leaf length> leaf venation> leaf ratio.2. The variation range of four phenotypic differentiation coefficients was 0.27%～24.68%. The average coefficient of phenotypic differentiation among populations was 7.97%, while the average coefficient of phenotypic differentiation within groups was 92.03%, so the variation within groups was the main source of variation.3.45 random primers were selected from Invitrogen Corporation for the amplification reaction in the experiment.11 of which showed highly efficient amplification and were used for 60 germplasm in amplification test. The bands were clear and more polymorphic. All the bands were polymorphic in 81 loci and the ratio of polymorphic was 100%. Genetic diversity was abundant that judged from the average value of Shannon index (0.509), Nei index (0.3425). Gst index (0.062). Genetic diversity within populations possessed 93.8% and that among populations possessed 6.2% of the total. We can conclude that genetic diversity of Alnus rubra mainly from within populations.4. Based clustering analysis of phenotype and molecular makers of Alnus rubra, this paper suggested that the germplasm of No.33,37,40,41,42,43,44,45,46,48,55,57,58 and 59 from LiuHe population, as well as those of No 1,2,3,4,9,10,11,12,16,17,19,20,21,22,23, 24,25,26 and 27 from XiaShu population,were need to preserve as breeding material.,...