Genetic Diversity And Population Structure Analysis Of Carex L.Based On SSR Markers Generated By RNA-sequencing

Carex L.plants are perennial herbs of the Cyperaceae family,which are playing an increasingly important role in landscaping,animal husbandry production,and ecological restoration due to its strong self-propagating ability and long growth duration.In order to clarify the genetic diversity among Carex species and its relationship with regions,identify Carex species,and explore Carex genetic information,this study developed SSR molecular markers based on the transcriptome sequencing of Carex breviculmis.It analyzed the genetic diversity and population structure of 68 Carex resources to lay the foundation for the identification and genetic breeding of Carex species.The main research results are as follows:(1)In this study,36,403 unigenes with a total length of 41,724,615bp were obtained from Illumina RNA sequencing data.The KEGG classification annotated 11,871 unigenes into 25 groups,and the GO classification annotated 11,629 unigenes into 3 large groups.The KEGG pathway enrichment analysis showed that 8,440 unigenes were annotated to 50 metabolic pathways.NR protein alignment showed that Carex was closest to Anass comsous,followed by o Elaeis guineensis and Phoenix dactylifera.(2)We developed 8,776 simple sequence repeat(SSR)molecular markers and screened 42 pairs of primers with good polymorphism to amplify 68 Carex samples.As a result,a total of 180 bands were amplified,including 180 polymorphic bands.The polymorphism ratio is 100%,and an average of 4.3 bands are amplified per site.The PIC value of polymorphism content index is 0.017?0.492,the average polymorphism content is 0.253,the number of observed alleles,number of effective alleles,gene diversity index and Shannon information index are 1.999,1.371,0.240 and 0.387,respectively.It indicates that the genetic diversity among the various Carex samples is at a high level(3)The UPGMA clustering phylogenetic tree can classify 68 Carex species into two categories when the genetic distance is 0.428.The information has no significant effect.The PCA principal component analysis was divided into two distinct categories,which were consistent with the UPGMA classification results.The AMOVA results showed that the variation index between the groups was 14%,the Fst between the two groups was 4.191,and P>0.001 was a very significant level,indicating that 68 Carex.The genetic background of the materials is significantly different.In this study,68 fingerprints of Carex are established Different combinations of primer pairs can be used to identify multiple Carex at one time,which overcomes the difficulties of traditional identification methodsIn this study,8,776 SSR molecular markers were developed through the transcriptome sequencing of Carex.It fills the gap in molecular marker work of Carex,and has practical significance for the identification of Carex species and the selection of excellent varieties,etc.,and lays the foundation for the future gene mining of Carex.