| Hot pepper(Capsicum spp.)is annual or perennial herbaceous plants belonging to the Solanaceae Capsicum,is one of the most important vegetable crops worldwide.In hot pepper breeding,it is important to collect hot pepper germplasm resources and study their genetic diversity.There is more distant relation and great differences in genetics between foreign resources and domestic resources.Through introducing of foreign hot peppers,it would enrich the genetic background of domestic hot pepper.It lays a material foundation for the genetic breeding of pepper in China.In this experiment we used 30 hot pepper resources collected from abroad.Combining with agronomic traits,ISSR and MSAP markers,genetic diversity and epigenetic diversity of this collection were analyzed.This research will provide elite materials and theoretical reference for germplasm collection,genetic research and breeding practices in hot pepper.1.In order to efficiently use hot pepper germplasms introduced from abroad,this study analyzed and compared the genetic diversity of 39 main characters of 30 germplasms using genetic diversity indexes,coefficient of variation,and cluster analysis.Based on clustering analysis of 39 phenotypic traits.30 hot pepper accessions could be divided into 3 types while the Euclidean Distance was 13.75.Group?,Group?,and Group ?,including 8,12,and 10 accessions,respectively.Different degrees of diversity exhibited in different traits.There is obvious variation among hot pepper introduced from abroad,and genetic diversity is abundant.2.The genetic diversity of 30 hot pepper introduced from abroad were analyzed with ISSR markers.The results showed that 8 primers from 96 ISSR primers for amplified the DNA of hot peppers.Totally 1781 ISSR loci including 1389 polymorphic loci were produced,with a polymorphism rate of 77.99%.At the genetic similarity coefficients among level of 0.724,these varieties could be divided into 3 groups: there are 19 hot peppers in Group?,10 materials in Group?,only one material in Group ?.The results of principal coordinate analysis and clusteranalysis are generally consistent,and the results of cross-classification are more intuitive.This study is beneficial to the future study of excellent gene exploring and molecular-assisted screening.3.The methylation diversity at CCGG sites were surveyed in the genomes of 30 hot pepper germplasms introduced from abroad using MSAP technology.The results showed that 9 primer combinations from 63 primer combinations for amplified the30 hot peppers.The analysis of DNA methylation pattern showed that fully methylation was major methylation type in 30 hot peppers.However,in this study,MSP clustering and MISP clustering were all relatively discrete,and the related principal coordinate analysis was basically consistent with the clustering analysis results.The DNA methylation study did not gather Capsicum annuum L.into the same group.It is shown that the epigenetic variation of hot pepper is more abundant than the genetic variation of the genome.4.Based on morphological traits and ISSR molecular markers for genetic diversity analysis showed that the two methods of analysis to the Capsicum annuum L.basically get together for the same class.and DNA methylation analysis using MSP clustering and MISP clustering are not Capsicum annuum L.together for the same groups.This showed that epigenetic diversity is more discrete than genetic diversity,and 30 hot pepper introduced from abroad germplasm resources have more epigenetic diversity than genetic diversity. |
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