Genetic Relationship Analysis Of Persimmon By SSR?SCoT And IRAP Molecular Markers

Diospyros kaki Thunb.belongs to Diospyros L.in the genus Ebenaceae L.Diospyros L.has a long history of cultivation in China,and has a rich variety of Diospyros germplasm resources.Now it has more than 1,000 in China.A variety of Diospyros species is distributed throughout the country.Because of the rich germplasm resources,there are numerous researches on Diospyros plants in China,including many studies on the genetic relationship of persimmon germplasm resources.However,the materials used in the research institutes are mostly limited.A small number of diospyros germplasm resources have been studied and analyzed.There have been no comprehensive and systematic studies on Diospyros species,especially for the construction of genetic maps of Diospyros species.In the context of the rich varieties of resources of the National Persimmon Germplasm Resource Center,this experiment was based on previous studies to select suitable molecular markers for genetic maps with high polymorphism rates and good amplification effects.A total of 268 Diospyros plant materials from persimmon germplasm resources were analyzed by genetic diversity and population structure analysis using SCoT,IRAP,and SSR,and the differences between the three groups were compared.It is a comprehensive and systematic study of resources and selects a suitable molecular marker method for the research of Diospyros plants,providing experimental and theoretical basis for the future genetics and breeding of Diospyros plants,promotion of quality resources,and feasibility of map construction.Through this experiment,the following results were mainly obtained:1.By calculating the ratios of SCoT,IRAP and SSR three molecular markers polymorphic bands,we found that the three molecular markers have higher levels of polymorphism.Using NTsys-pc 2.01 software to analyze the data of three molecular markers,the genetic matrix and their genetic coefficients of 268 samples of Diospyros spp.were obtained.The UPGMA method was used for cluster analysis.The results of cluster analysis showed that the three molecular markers could be classified into three categories.2.The 268 Diospyros species from different origins were divided into five regions(North China,East China,South Central,Northwest China,and Southwest China),and their genetic differentiation was analyzed.It is concluded that their genetic differentiation was low and the level of gene exchange was high,showing that there was frequent gene exchange between them.Using SCoT,IRAP,and SSR molecular markers to analyze the genetic similarities in five regions,we found that the genetic distance between North China,East China,Central South and Northwest China have a relatively close relationship,and the genetic similarity was high.The genetic distance between the southwest region and the other four regions is relatively low,and the degree of genetic similarity is low too.3.After a comparative analysis of morphological characteristics,we found that the morphological characteristics of 'Binxian steeple persimmon','Qianxian persimmon' and 'Huxian persimmon' were identical,and we judged them to be synonymous varieties.These three species were clustered or closely spaced in the three molecular clustering analysis of SCoT,IRAP and SSR,indicating that similar or identical morphological characteristics were verified in molecular markers.Thus,it can be predicted with one or several molecular markers to identify clustering unknown genus Diospyros synonyms varieties.4.By comparing three molecular markers,it was found that the three molecular markers all have higher polymorphisms,and both the Diospyros spp and the Diospyros L.can be distinguished.The polymorphism detection efficiency(the total number of polymorphic bands/the number of polymorphic primers)of the three molecular markers was SSR(13.3)>IRAP(8.6)>SCoT(7.7).Among them,the results of SSR molecular markers are the most practical,the highest polymorphism and the best.Followed by IRAP molecular markers,and finally SCoT molecular markers.5.Combined with three molecular markers and single-copy homologous gene analysis among species,the order of the genetic relationship between Diospyros spp.and Diospyros L.from far to near is: D.kaki Thunb.var.silvestris,D.oleifera Cheng,D.Deyangnsis,D.Jinzaoshi,D.lotus L.,D.glaucifolia Metc.,D.virginiana L.,D.cathayensis Steward.