Constructing A Core Collection Of Hubei Genuine Angelica Biserrata

Angelica biserrata(Shan et Yuan)Shan et Yuan is an important medicinal plant in Chinese traditional medicine.Its roots,which are known as Duhuo which first recorded in the "Shen Nong Materia Medica",named for "stems upright,not shaken by the wind".Duhuo had a long history of application which widely used to treat various inflammation,arthritis,and headache.Coumarin compounds rich in types are the main medicinal ingredients in Duhuo,and osthole and columbianadin are the index compounds for the quality evaluation of Duhuo.At present,the source of the supply in the market is mainly home-grown resources.Hubei,Chongqing,Gansu,Sichuan and other provinces are the main producing areas whose output is relatively large.However,due to various reasons such as soil degradation and weather factors in the production area,the quality and yield of Duhuo is decreasing.The differences in harvesting and processing methods in various regions have led to uneven quality of the market.In the current market circulation of Duhuo,many varieties of different regions are mixed,and the genuineness is gradually lost,resulting in a decline in the quality of the germplasm.The core collection preserves the most representative samples of the germplasm resources,which can effectively promote the research and utilization of germplasm resources.Currently,there is no core collection to be constructed in Duhuo,and it is impossible to effectively carry out breeding to improve yield and quality and other researches on molecular genetic characteristics.As a genuine medicinal material in Hubei,"Ziqiu Duhuo" has been protected by the National Geographical Indication Product with the characteristics of good quality and high yield.Therefore,carrying out the evaluation and the construction of core collection of "Ziqiu Duhuo" genetic resources can avoid or reduce the further loss and destruction of the germplasm resources of Duhuo and will help promote the effective protection and scientific management of the genetic resources,and lay the foundation for development and utilization of resources,cultivation of new varieties and ecological cultivation in the future.As the genuine area of "Ziqiu Duhuo",Changyang and its surrounding areas,Hubei province have unique natural geographical conditions and ecological environment.In this study,208 "Ziqiu Duhuo" samples of 3 wild populations were collected from Changyang-related regions.In this study,the transcriptome of A.biserrata was sequenced for the first time,and developed highly polymorphic SSR molecular markers based on the transcriptome.The SSR markers were used to comprehensively evaluate the genetic diversity of208 A.biserrata germplasms.According to literature reports,6 coumarin compounds were selected to evaluate the quality of 208 Duhuo medicinal material corresponding to genetic evaluation materials.Finally,the core collection of A.biserrata was constructed by combining genetic diversity and metabolic content data.Firstly,the database function annotation and SSR distribution characteristics were performed on A.biserrata transcriptome.17 pairs of highly polymorphic SSR molecular markers were developed based on transcriptome data.The molecular marker data was used to analyze the genetic diversity,genetic structure and genetic differentiation of 3 populations.A total of 132 alleles were amplified from 17 SSR loci.The values of three main genetic parameter of 17 loci(Ne: 3.89,I: 1.52,PIC: 0.67)indicated that the wild germplasm resources collected in this study owed higher genetic diversity.3 populations were divided into 2 groups,among which Puling and Gaofeng were one group,Langping was a separate group,the genetic diversity in Langping population was relatively high among 3 populations.Genetic variation mainly existed within the population(94%),while only 6% genetic variation existed between populations.The degree of genetic differentiation among 3 populations was relatively small,and the gene flow was relatively large.There were significant differences in the average content of 6 coumarin compounds in 208 Duhuo.Among the 3 populations,the average content of 6coumarin compounds was quite different,especially osthole and columbianadin.The average content of osthol in the Lanping population was highest in the 3 populations,but the average content of columbianadin was lowest.On the contrary,the average content of columbianadin in Puling and Gaofeng populations was 2-3 times of Langping population,but the average content of osthole was only one-tenth of Lanping population.According to the genetic and metabolic data,the least distance stepwise sampling strategy(LDSS)and sampling ratio with 40%～10% were adopted to construct seven preliminary core collections,of which the 20 CC core collection(sampling ratio with 20%,42 accessions)was screened as the final core collections to preserve the core and representative materials based on genetic diversity and supplemented by metabolic components.The T test proved that there was no significant difference in the main genetic diversity index between 20 CC and original germplasm at the level of α=0.05.it could retain more than 90% of the genetic diversity of the original germplasm,and the total content of coumarin of the 20 CC has increased than original germplasm.In this study,the SSR molecular markers developed based on transcriptome can provide a richer source of markers for germplasm identification,molecular marker-assisted breeding and genetic map construction of A.biserrata.A comprehensive evaluation of the genetic diversity of A.biserrata germplasm resources provides important clues for assessing the gene diversity and excavate good genes of this species.And it can protect,develop and utilize the germplasm resources more efficiently.A comprehensive evaluation of the metabolism differences between different populations and different samples is conducive to the screening of good populations and high-quality germplasm of A.biserrata,and provides data support for selection of new varieties.The successful construction of the core collection will contribute to preserving and managing the wild germplasm resources of A.biserrata and providing a material basis for the breeding of this medicinal plant.