Resource Investigation And Genetic Diversity Analysis Of Wild Fagopyrum.cymosum In China

Fagopyrum cymosum is a kind of perennial herb of Fagopyrum in Polygonaceae.It is a national second-class protected plant,and has great application value in medicine,health care,animal husbandry and other fields.In recent years,with the in-depth research on the pharmacological effects of golden buckwheat and the growth of pharmaceutical demand,the original habitat area of wild golden buckwheat has been gradually reduced by environmental changes,human factors,and a large number of excellent germplasm resources are in danger of extinction.Therefore,it is particularly important to carry out the investigation and collection of wild resources.In order to fully explore the abundance and genetic characteristics of rare wild buckwheat germplasm resources in China,this study conducted a field investigation of wild golden buckwheat resources,systematically investigated 13 provinces(districts)and 62counties(cities and districts)across China,collected a total of 530 wild golden buckwheat germplasm resources,and established a remote protected resource garden.1.The resource distribution map of wild buckwheat was drawn based on the original habitat information.The results showed that the wild buckwheat resources in China were mainly distributed in the subtropical monsoon climate area with an altitude of less than 3500 m,E 90°44′～119°36′,N 24°59′～33°53′.Based on the characteristics of geographical information and population structure,the distribution of wild golden buckwheat in China is roughly divided into three regions: the special concentration area of high-altitude groups in Southeast Tibet,the suitable habitat area with rich middle and low-altitude taxa in southwest China,and the suitable areas with single low-altitude groups in the middle and lower reaches of the Yangtze River.Phenotypic identification showed that the population of golden buckwheat in various regions had distinct phenotypic characteristics and showed complex and diverse phenotypic traits(plant type,inflorescence,leaf shape,grain and root type).These trait differences were the result of the synergistic effect of its genetic factors and a variety of ecological factors(altitude,light,climate,geological environment,etc.).2.The agronomic traits evaluation of wild golden buckwheat showed that the variation coefficients of various agronomic traits of different golden buckwheat groups were rich,and all kinds of agronomic characters have great variation,which reflects the rich character diversity of wild golden buckwheat population.According to field observation and character analysis,plant type is decisive for other characters,resulting in great biomass gap between different groups.The buckwheat population can be divided into 9 morphological categories according to the differences of plant type,number of branches at the base and leaves.There were significant differences in 1000 grain weight and flavonoid content(Rutin,Quercetin,Pyroside and Kaempferol)of golden buckwheat grains at different altitudes(P < 0.05).The flavonoid content of golden buckwheat grains in different regions was related to groups and altitudes.Through the correlation analysis of traits,it is found that there is an obvious correlation between quantitative traits,which proves that the interaction between various traits mainly comes from stable genetic factors and is also affected by certain environmental factors.3.The genetic diversity of 497 golden buckwheat germplasm resources was analyzed by SSR molecular markers.The clustering results showed that the wild golden buckwheat resources in China were divided into two groups and four branches: according to the number of samples,they were divided into the first branch of 277 resources from central provinces and southwest China;The second branch of 161 resources from central provinces and regions;The third branch from 52 resources in Tibet and the fourth branch from 7 special resources in Yunnan Province.The genome size of 88 candidate materials was detected by flow cytometry and their ploidy was analyzed.It was further found that the concentrated population of golden buckwheat in Tibet was diploid F.pilus;Buckwheat has a large number of mixed diploid populations in Southwest China,and there are a large number of complex diploid populations;Most of the golden buckwheat in central provinces are tetraploid F.cymosum with a single group.Through the systematic investigation and collection of wild buckwheat germplasm resources in China,a large number of excellent germplasm resources were harvested,which effectively enriched the buckwheat crop germplasm bank and laid a precious material foundation for buckwheat research;It provides a reference for the taxonomic evolution of buckwheat.The research results are of great significance in protecting wild plants,maintaining species diversity of ecological environment and optimizing buckwheat characteristic industrial system.