| Guizhou Province because of its special geological landform and complex and diverse microclimate types,it has a rich Camellia spp.gene pool,but the diversity level of Camellia spp.germplasm resources and the relationship of germplasm resources were still unclear.In this study,we determined phenotypic characters,economic characters and fatty acid components of the main germplasm resources of Camellia spp.in Guizhou,and studied genetic diversity based on SSR molecular markers.The aim is to improve the basic information base of main Camellia spp.germplasm resources in Guizhou Province,and to understand the diversity level and the genetic relationships of germplasm resources.They can provide scientific reference for the subsequent breeding of improved varieties and resource exploitation and utilization.The main research results were as follows:(1)The phenotypic traits of the main Camellia spp.germplasm resources in Guizhou had rich genetic variation and high diversity level.The mean coefficient of variation between germplasm resources,coefficient of variation within germplasm resources,shanmon-weaver diversity index(H)and simpson genetic diversity index(D)of seven fruit phenotypic traits were 39.09%,22.74%,1.95 and 0.83,respectively.The phenotypic characters of 6 leaves were 17.22%,12.43%,2.07 and 0.86,respectively.The phenotypic characters of 6 flowers were 19.94%,6.57%,1.91 and0.82,respectively.The fruit phenotypic traits varied greatly within and among cultivars,while the flower phenotypic traits varied little within cultivars.From the analysis of variance,we can see that the variation of phenotypic traits mainly comes from the difference of varieties.Cluster analysis showed that phenotypic characters had a certain correlation with the region.(2)The 4 economic characters and 9 fatty acid components had high diversity,and the mean H and D diversity indexes were 2.02 and 0.845,respectively.The variation coefficients of Dry kernel rate(9.63%),palmitic acid(8.77%),oleic acid(3.53%),saturated fatty acid(6.99%)and unsaturated fatty acid(0.89%)were small,The variation of other characters was great.Based on correlation analysis and principal component analysis,oleic acid,linoleic acid,unsaturated fatty acid,saturated fatty acid,fresh seed rate,dry seed rate,dry kernel rate and oil content of the dry kernels were selected as the core indexes for comprehensive evaluation of Camellia spp.in Guizhou.(3)A total of 295 alleles were amplified by 12 pairs of primers,with an average of 24.538.The mean values of Shannon index(I),observed heterozygosity(Ho),expected heterozygosity(He)and gene diversity(GD)were 2.355,0.972,0.856 and0.860,respectively,they showed high levels of genetic diversity.The genetic structure analysis showed that the best group was 2,but K=8,three groups with special characteristics could be divided.They were C.meiocarpa germplasm resources from Qiandongnan Miao and Dong Autonomous Prefecture of Guizhou Province(QDN),the C.oleifera germplasm resources from Jin Ping Guizhou Province and germplasm resources from some areas of QDN.According to the Euclidean distance cluster analysis,the Euclidean genetic distance of 351 Camellia spp.germplasm resources ranged from 0 to 8.19,which could be divided into 4 groups.(4)In this study,it was found that among 351 germplasm resources,we identified1 combination of synonyms and 7 combinations of homonyms.A total of 31 primers from Co Ug3417,Co Ug13753,Co Ug5179 and Co Ug11592 were used to construct the fingerprint of 176 Camellia spp.germplasm resources.The results provided a scientific reference for the management and innovative utilization of germplasm resources of Camellia spp.in Guizhou.The results of this study not only mastered the phenotypic,economic and molecular diversity of the main Camellia spp.germplasm resources in Guizhou Province,but also identified the germplasm resources in Guizhou Province,which was conducive to the collection,conservation,management,development and utilization of oil tea germplasm resources in Guizhou Province. |
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