Genetic Diversity Of Paeronia Rockii Germplasm Assessed By EST-SSR Markers

Paeonia Rockii(SG Haw et LA Lauener)T.Hong et JJ Li)is a peony group plant of Paeonia lactiflora.It is an important part of the Chinese peony family,and its wild species is important for Chinese peony cultivars.Originating species,which form the unique northwestern(purple spot)tree peony group as an important germplasm resource,is the second largest group of peony in China in recent years.Purple Peony peony has become an important flower resource and emerging oil crop resources in Gansu Province,and has a huge industrial prospect.In recent years,due to the complex origin of the purple patch peony,different regions have their own names,often have the same name as the foreign matter,the phenomenon of the same thing in the same name.There are problems in the production,marketing and promotion of the seedlings,such as confusion,mutual generation,falsehood,etc.,affecting the local industry.Reputation,therefore,it is extremely important to establish a scientific,reliable,rapid and simple identification system.In this study,morphological markers and EST-SSR markers were used to analyze the genetic diversity of 57 P.purpurea varieties using cluster analysis.Concluded as follow:1.A total of 65 polymorphic sites were amplified from the 57 pairs of primers using EST-SSR markers.A total of 4.333 alleles were amplified from each pair of primers,and the variation range was from 2 to 7.Polymorphism information content(PIC)ranged from 0.132 to 0.836,with an average of 0.618.This indicates that 57 purple peony cultivars tested have abundant genetic diversity,and the 15 pairs of EST-SSR primers selected have high polymorphism.2.The genetic similarity coefficient values of the tested peony cultivars varied from 0.5212 to 0.800 in the study,indicating that there are complex genetic backgrounds among the peony cultivars,which have certain similarities and differences.57 P.purpurea clustered at the genetic similarity coefficient of 0.5212,and when the genetic similarity coefficient had the maximum value of 0.8000,both HGXC and JBDY first clustered together.Together,it shows that there is a close relationship between the two varieties,and the difference between the varieties is small.3.Use the UPGMA method to construct dendrogram,the pattern analysis of genetic relationship among varieties of Paeonia suffruticosa,The comparative morphological study divided the peony pattern into two categories: single flowers and Garret type.The genetic similarity coefficient was 0.6255 and it was divided into 8 categories.The distribution of 8 types of peony cultivars was divided into 8 cluster groups.From the point of view,there is no correlation between the classification of clustering groups and the division of traditional morphological patterns,and the clustering of single flower species with more than one species tends to be clustered with the same type of flowers,indicating the kinship among single flower species.The relationship is relatively close;this is because,when the evolutionary pathways are the same,the phylogenetic relationships among various flower varieties also appear relatively close.4.Analysis of genetic relationship among tree peony varietiesby flower color.When the genetic similarity coefficient is 0.5870,57 varieties can be divided into 4 categories,Class I is 51 purple peony cultivars containing 7 colors,and the same flower color varieties did not come together first.Class II is composed of 4 varieties with 2 different flower colors;further illustrates that there is no correlation between the classification of genetic clusters and the classification of flower color;Class III is a single species of 'Huangyun',which is clustered into a single category.It fades after flowering and changes from yellow to white.Category IV is Sichuan peony,which is clustered into a single species.The main reason is that it is a hybrid of Sichuan Peony andP.rockii,and has a complex genetic background.It shows that the relationship between the cultivated varieties of peony and the varieties bred by interspecific hybridization is far away.