| Camellia oleifera Abel,as one of the four woody oil materials,has extremely high economic value.With the continuous development and progress of the C.oleifera Abel industry,people are paying more and more attention to the C.oleifera Abel germplasm resources.Compared with the current main varieties of C.oleifera Abel,wild C.oleifera Abel in the northern margin of the distribution area is rich in genes and more resistant to cold,and is a valuable resource for C.oleifera Abel breeding.In this study,11 wild C.oleifera Abel populations from Xionghe(XH),Maopu(MP),Wangwan(WW),and Balifan(BLF)were selected in Xinxian County in the hinterland of Dabie Mountains in the northern margin of C.oleifera Abel.341 copies,using 16 pairs of SSR molecular markers and conventional determination methods,were subjected to phenotypic evaluation and genetic diversity analysis,and the following main research results were obtained:1.The phenotypic variation of wild C.oleifera Abel in Xinxian County were very abundant,and the traits of C.oleifera Abel leaves,flowers,and fruits in the 11 groups surveyed have significant or extremely significant differences between groups and within groups.Among the 21 traits of leaves,flowers,and fruits determined,the traits of leaf area,stamen length,stamen number,and peel thickness can be used as the basis for selection of superior trees.The main morphological indicators of leaves,flowers and fruits are significantly or extremely significantly related to the average annual temperature and annual precipitation.2.The phenotypic differentiation coefficient shows that among the phenotypic trait variations of wild C.oleifera Abel population,intra-group variation is greater than inter-group variation,which is the main source of variation.Among the 11 groups,XH is the group with the most stable phenotypic traits,and BLF,KB,and MP are relatively unstable.3.Based on PCR amplification of universal primers and published primers,16 pairs of SSR primers with high polymorphism were screened.Using these 16 pairs of primers,the genetic diversity of the wild C.oleifera Abel population was tested,and a total of 174 alleles were amplified.For genes,the average number of alleles(Na)is 10.875,the average expected heterozygosity(He)is 0.739,the observed heterozygosity(Ho)is 0.718,and the average polymorphism information index PIC is 0.739.4.The 11 wild C.oleifera Abel populations in Xinxian County have high genetic diversity,and the average expected heterozygosity(He)between the populations is 0.735.The molecular variance shows that genetic variation mainly comes from within the population,accounting for 88.21% of the total variation.Although there is also some genetic differentiation between groups,the genetic differentiation coefficient Fst between groups is small,with an average of only 0.04.According to the principal component analysis and cluster analysis results of Structure and PCOA,these 11 groups can be roughly divided into two categories.Mantel test preferentially grouped some close-distance groups together,but there was no significant correlation between genetic distance and geographic distance.5.The gene flow of 11 wild C.oleifera Abel populations in Xinxian County is gr--eater than 1,indicating that the gene exchange among these groups is relatively frequent.It is speculated that the possible reason is that wild C.oleifera Abel is less affected by genetic drift during natural selection,resulting in the decline of genetic diversity. |
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