| Camellia sinensis’ Guiding Niaowangzhong ’,a tea species of Theaceae genus in Theaceae family,is tea germplasm resource with local characteristics mainly distributed in Yunwu town in the south of Guiding County,Guizhou Province.C.sinensis ’ Guiding Niaowangzhong ’ has a long history of cultivation and rich genetic diversity resulting it could be a valuable material for variety breeding and resource development and utilization.In the reseach,95 individual plants of C.sinensis ’ Guiding Niaowangzhong ’ as the research object.The genetic diversity of C.sinensis ’ Guiding Niaowangzhong ’ was discussed using the characteristics of morphological traits,biochemical components and molecular level characteristics carried out by EST-SSR molecular marker technology and C.sinensis ’ Guiding Niaowangzhong ’ with high EGCG content were selected,so as to provide a theoretical basis for the subsequent breeding and promotion of tea varieties.The main results of this study were as follows:1.study on genetic diversity of morphological traits of Camellia sinensis ’ Guiding Niaowangzhong ’The study investigated and evaluated the morphological traits of the screened individual plants with reference to the description specification of tea germplasm resources,carried out the coefficient of variation and diversity analysis of morphological characters.The results showed that the variation coefficient of descriptive traits per plant of 95 species of C.sinensis ’ Guiding Niaowangzhong ’ranged from 11.61% to 41.11%,the diversity index ranged from 0.23 to 1.15,the coefficient of variation of numerical traits ranged from 10.50% to 29.11%.The diversity index was above 1.80.The average coefficient of variation of morphological traits was 24.36% and the average genetic diversity index was 1.01.In conclusion,the variation and genetic diversity of C.sinensis ’ Guiding Niaowangzhong ’ was rich.According to the morphological traits,95 individual plants of C.sinensis ’ Guiding Niaowangzhong ’ could be clearly grouped into 4 groups.2.Study on genetic diversity of biochemical components of Camellia sinensis ’Guiding Niaowangzhong ’The biochemical components of 95 individual plants of C.sinensis ’ Guiding Niaowangzhong ’ were detected by HPLC and the coefficient of variation and diversity of biochemical components were analyzed.The results showed that the content of water extracts,amino acids,tea polyphenols,biochemical components,genetic diversity index and catechins of 95 species of C.sinensis ’ Guiding Niaowangzhong ’ were38.08%～52.28%,3.48%～11.51%,14.37%～25.97%,30.63%,1.93 and 37.45%,respectively.It could be seen that the variation degree of biochemical components of C.sinensis ’ Guiding Niaowangzhong ’ was relatively high,leading the rich variation and diversity.According to the clustering of biochemical components,the strains of C.sinensis ’ Guiding Niaowangzhong ’ were grouped into 5 groups.3.Study on molecular genetic diversity of Camellia sinensis ’ Guiding Niaowangzhong ’Using EST-SSR molecular marker technology,43 pairs of polymorphic EST-SSR primers were selected to PCR amplify the DNA of 95 single plant resources of C.sinensis ’ Guiding Niaowangzhong ’.According to the amplification results,449 alleles were detected by 43 pairs of primers.The average number of effective alleles(Ne)was6.1331 while t he average polymorphism information content(PIC)of the primers was0.7899 and the pic values of the tested primers were greater than 0.5,showing high polymorphism information.Nei’s genetic diversity index(H)of single plant resources of C.sinensis ’ Guiding Niaowangzhong ’ was 0.8123 on average.Shannon information diversity index(I)averaged 1.9360.The average observed heterozygosity(Ho)was0.0535.while the average expected heterozygosity(He)was 0.1833 and the difference between them was 0.1298.In conclusion,the C.sinensis ’ Guiding Niaowangzhong ’has high genetic diversity.The 95 single plant resources of C.sinensis ’ Guiding Niaowangzhong ’ could be further divided into 5 groups.The results of cluster analysis showed that there were some differences in the genetic relationship between different individuals,and the analysis of population structure showed that the genetic background of the population was small.4.Screening of single plant of Camellia sinensis ’ Guiding Niaowangzhong ’ with high EGCGThe EGCG content of 95 individual plants of C.sinensis ’ Guiding Niaowangzhong ’ was detected by HPLC.The individuals of C.sinensis ’ Guiding Niaowangzhong ’ was screened with the EGCG content greater than 100 mg/g as the standard.The results showed that 36 individuals of C.sinensis ’ Guiding Niaowangzhong ’ with high EGCG(> 100 mg/g)were screened from this research material,accounting for 37.89% of the total number of individual plants.The highest EGCG content of single plant NW29 was 147.30 mg/g. |
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