Study On Genetic Structure And Diversity Of Wild Rosa Rugosa Population In The Fragmental Habitats Along Rongcheng's Seashore

Wild rose( Rosa rugosa Thunb.) has been ranked in the national second-class level protected plants .It is a kind of natural idioplasmic resource having a real economic and ecological significance. There are widely primal habitats along the Rongcheng's seashore of Shandong province,but more and more disturbances from human beings make the habitats of wild rose fragmental and the population distributes in the inconsecutive habitats, its genetic structure and diversity have been seriously influenced. In the fragmental habitats from Liukuang village in Rongcheng city, 17 clusters(C1 ~ C17) of wild rose have been selected from the population to be experimented; Their genetic structure and diversity have been analyzed using RAPD technique .Additionally, combining fragmental with reproduction traits of wild rose clusters, the endanger cause for species has been discussed as well as protection methods suggested .Establishing a best RAPD program of wild rose according to Koppitz ,133 loci have been amplified from 15 primers by RAPD, of which 1 monomorphic locus and 28 unique loci to some clusters; The average of P (percents of polymorphic loci) within clusters is 11.54%, the average of Ae (number of efficient allele) is 1.0755, the average of H(expected heterozygosity) within clusters is 0.0431; Percent of polymorphic loci is positively correlative with the sample size and sample area, and Shannon information index is positively correlative with the sample size. Percent of polymorphic loci(P) of the whole population is 78.20%, the average of Ae is 1.4017, the average of Hwithin population is 0.2426, Shannon information index(I) is 0.3710;Compared with another two populations of Hunchun and Muping, the average of P Ae.H I within the clusters of Rongcheng are lowest, ie. Hunchun>Muping>Rongcheng, which indicate that genetic diversity within the clusters of the three populations decreases one by one with more and more disturbances exsist. Among the 17 clusters studied in this research, clonalones have been found in sixteen. Clones usually appear in closer ones, but in some cluster such as C1 C4, C5 C6 C9 C13, there exists the crossing pattern.The conclusions of studies on the genetic structure and genetic divergence indicate that Gsr Genetic divergence) of all RAPD loci among clusters vary from 0.1000 to 0.9929 and the mean is 0.8236; The Nm(gene flow) vary from 0.0000 to 4.5008 and the mean is 0.1071, which is greatly less than 1, so there is serious genetic drift within and among clusters. The relationship of Gst within the clusters of the three poplutions is HunchunMuping>Rongcheng, which indicate that more the disturbance increases, more the gene exchange decreases among the clusters .From Nei's unbiased measures of I (genetic identity) and D (genetic distance) by RAPD, the shortest genetic distance is found between C12 and C13, which is 0.0788, The longest genetic distance is 0.4101 just between C3 and C12; Chi-square proof-test of all RAPD loci among clusters indicates that 75% of loci prominently departs from Hardy-Winbergii equilibrium.Based on the genetic traits of Rosa rugosa population along the seashore of Rongcheng and the situation of its framental habitats,the methods of protecting it should be the combining in situ with ex situ protection methods. Firstly, combined with the programm of protecting area of swan, the habitats of the wild rose should be considered in it. The population of the wild rose should be protected in situ, combined with manpower methods to hasten the exchange of gene flow among the clusters. Secondly, in transferring them to other places, it should be trying best to pick more ones from different clusters to cultivate them in blending, and then conserve the genetic diversity of Rosa rugosa in the primal habitats.