QTL mapping for fiber strength and Verticillium wilt resistance with RAD-seq in upland cotton

Working group session: 
Structural Genomics
Presentation type: 
oral
Authors: 
Wang, Yangkun; Zhang, Tianzhen; Ning, Zhiyuan; Hu, Yan
Presenter: 
Wang, Yangkun
Correspondent: 
Zhang, Tianzhen
Abstract: 
Cotton (Gossypium hirsutum) is an allotetraploid with a narrow germplasm base, which made the discovery of single nucleotide polymorphism (SNP) markers difficult. To conduct QTL mapping for fiber strength and resistance to Verticillium wilt, we developed a population of 161 recombinant inbred lines (RILs) from a single seed derived from across between Acala Prema and Chinese cultivar 86-1. Markers were produced by the restriction-site associated DNA (RAD) sequencing, using massively parallel and multiplexed sequencing of reduced-representation. A total of 21,247 SNPs were identified between the two parents. Additionally, simple sequence repeat (SSR) markers were combined with RAD markers to produce genetic linkage map comprising 3,321 loci. We examined the fiber qualities in six environments, and Verticillium wilt trials were conducted in the artificial disease nursery inoculated with mixed isolates and greenhouse individually with Verticillium wilt defoliating isolates V991 and VD8 over a 2-yr period. Based on this, we detected the stable fiber strength QTL qFS-D3-1 on chromosome 17 with LOD scores ranging from 3.76 to 10.06, which account for 2.56-18.35% of phenotypic variance, and the major resistance QTL qVW-D9-1 on chromosome 23 with LOD scores ranging from 4.41 to 34.23 accounting for 14.9-52.95% of phenotypic variance. The results suggested that the development of SNP markers by using RAD-seq was efficient and the QTL detected in this study will facilitate the marker-assisted selection in cotton breeding.