Construction of a High-density Genetic Map and Identification of Candidate Genes for Resistance to Fusarium Wilt based on the Resequencing of Recombinant Inbred Line Population in Gossypium Barbadense

Abstract Background: Resistance to Fusarium wilt (FW) is of great significance for increasing the yield of Gossypium barbadense. Most published genetic studies on G. barbadense focus on yield and fiber quality traits, while there are few reports on resistance to FW. Results: To understand the genetic basis of cotton resistance to FW, this study used 110 recombinant inbred lines (RILs) of G. barbadense obtained from the parental materials Xinhai 14 and 06-146, and Nannong was used to construct a high-density genetic linkage map. The high-density genetic map was based on the resequencing of 933,845 single-nucleotide polymorphism (SNP) markers, and 3627 bins covering 2483.17 cM were finally obtained. The collinearity matched the physical map. A total of 9 QTLs for FW resistance were identified, each QTL explained 4.27-14.92% of the observed phenotypic variation, and qFW-Dt3-1 was identified in at least two environments. According to gene annotation information from multiple databases, promoter homeopathic elements and transcriptome data, 10 candidate genes were screened in a stable QTL interval. qRT-PCR analysis showed that the GOBAR_DD06292 gene was differentially expressed in the roots of the two parents under FW stress and exhibited the same expression trend in the G. barbadense resource materials.Conclusions: These results indicate the importance of the GOBAR_DD06292 gene in FW resistance in G. barbadense and lay a molecular foundation for the analysis of the molecular mechanism of FW in G. barbadense.