Phenotypic Character Evaluation And SSR Genetic Diversity Analysis Of Solanum Germplasm Resources

Eggplant(Solanum melongena L)is a self-pollinating crop that originated from perennial shrubs in tropical regions of India and Southeast Asia.It was later introduced into China and cultivated and domesticated.Because eggplant is rich in nutrients,it is loved by consumers,and the cultivation area of eggplant is constantly expanding.At present,China is the largest producer and the largest consumer of eggplant,so it contains rich eggplant germplasm resources.Through continuous research on eggplant germplasm resources,not only is it conducive to the collection and preservation of eggplant germplasm resources,to expand the gene library of excellent germplasm,but also can provide reference value for eggplant variety improvement and new variety breeding.In this study,a total of 77 eggplant materials,including wild species,wild relatives and cultivated species,were collected and evaluated from the phenotypic traits and SSR molecular markers to explore the genetic diversity of the eggplant materials tested.The following conclusions are obtained:1.The data collection,assignment and comprehensive analysis of 17 phenotypic traits of 77 eggplant germplasms showed that,using diversity analysis,the variation coefficient of 17 phenotypic traits varied from 0.15 to 0.69,and the average value was 0.36 The index ranged from 0.474 to 2.059,with an average value of 1.29.In both indicators,the variation of fruit length is relatively large,respectively 0.56 and 2.059,which is rich in genetic diversity.The 17 traits have relatively complicated correlations.The principal component analysis summarizes the 17 traits into 7 main factors,with a cumulative contribution rate of 74.704%,covering most of the genetic information.Using the clustering method of phenotypic traits,77 eggplant materials tested were divided into 4groups at the Euclidean distance of 20.The clustering results can reflect the genetic relationship between the materials to some extent.2.Using SSR molecular markers to analyze the genetic diversity of 77 eggplant test materials,the results showed that the screened 51 pairs of polymorphic primers amplified a total of 260 bands,of which 144 polymorphic bands On average,each pair of primers can amplify 2.82 polymorphic bands,with a polymorphic ratio of 55.38%.In the cluster analysis of 77 materials,the genetic similarity coefficient varied by 0.43-0.94.At the similarity coefficient of 0.60,the materials can be divided into four groups,of which the second group can be further divided into two subcategories at the similarity coefficient of0.612.Compared with the cluster analysis of phenotypic traits,it shows that cluster analysis based on SSR markers can more accurately reflect the kinship between materials.3.Using SSR molecular markers to analyze the group structure of 77 eggplant test materials,the results show that when K = 6,the taxonomic classification is the most reasonable,that is,it is divided into six groups.Among them,Pop Ⅰ has the closest relationship with Pop Ⅵ,and farthest with Pop Ⅱ and Pop Ⅲ;Pop Ⅳ has a closer relationship with Pop Ⅴ.Of the 77 test materials,16.02% of the materials have mixed sources,there is gene exchange between varieties,and the genetic structure is relatively complex.Compared with cluster analysis of molecular markers,both of them can divide the variety types into a group,such as wild eggplant,but the group structure can provide an in-depth understanding of the genetic makeup of the material.