QTLs Analysis For Leaves Trichomes Trait In Ramie

Ramie is a unique natural fiber crop in China,and it is also widely used as forage in southern China.The trait of trichomes?which belongs to epidermal hair?is a distinct morphological feature that distinguishes cultivated ramie from its wild ancestor,ramie with green leaf.When ramie is used as forage,its crushing processability and feeding palatability will be affected by excessive leaves trichomes.Analyzing the genetic mechanism of leaves trichomes formation and achieving genetic improvement of this trait will help to improve the feeding quality of ramie.Therefore,this study carried out in-depth research on the genetic basis of ramie leaves trichomes traits and made the following progress.?1?Using ramie without leaves trichomes?QYZM?and leaves-trichomes cultivar"Feeding Ramie No.1?ZSZ1?"as parents.A total of 113 families of the group and the parents were used for high-throughput transcriptome sequencing.We completed population SNP typing,and constructed a high-density genetic map of ramie.The map was 2118.8cM in total length and contained 1085molecular markers which are evenly distributed in 14 linkage groups,and the average distance between markers is 1.98cM.?2?Collected phenotypic data of leaves trichomes on F₂ segregated population combined with genetic maps to complete ramie trichomes trait QTL mapping,a total of 9 trait QTLs were detected,of which a major leaves trichomes trait QTL was detected on chromosome 7 and 13 respectively,qLT7and qLT13.At the same time,QTL mapping of fiber-related traits was completed,and 8 stem diameter,6 stem length,6 bark weight,3 bark thickness and 10 fiber yield QTL were detected respectively.?3?We carried out in-depth QTL analysis of leaves trichomes traits.qLT7 and qTL13 were mapped to a genomic region of about 690 kb and 970 kb,respectively,with 77 and 135 genes in the interval by analysis the QTL interval genotypes of recessive recombinant plants using SSR markers and completing extreme trait mixed pool sequencing?BSA sequencing?.?4?Within the physical interval of q LT13,based on expression analysis,parental sequence variation and homologous sequence methods,four genes have been identified as qLT13 candidate genes,which can be used for subsequent functional verification.This study was the first to carry out genetic analysis of ramie leaves trichomes traits.QTL identification provided a target site for molecular marker-assisted selection of ramie leaves trichomes traits for forage,and laid the foundation for the analysis of the formation mechanism on ramie leaves trichomes trait.