Quantitative Trait Locus Mapping and Identification of Candidate Genes for Resistance to Fusarium Wilt Race 7 Using a Resequencing-Based High Density Genetic Bin Map in a Recombinant Inbred Line Population of Gossypium barbadense.

Wanli Han,Xiaojuan Deng,Qin Chen,Qianli Zu,Quanjia Chen,Aixing Gu,Yuxiang Wang,Xiaoshuang Lu,Jinfa Zhang,Yanying Qu,Jieyin Zhao,Duolu Li

doi:10.3389/fpls.2022.815643

Abstract

Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum (FOV) is one of the most destructive diseases in cotton (Gossypium spp.) production, and use of resistant cultivars is the most cost-effective method managing the disease. To understand the genetic basis of cotton resistance to FOV race 7 (FOV7), this study evaluated a recombinant inbred line (RIL) population of 110 lines of G. barbadense from a cross between susceptible Xinhai 14 and resistant 06-146 in eight tests and constructed a high-density genetic linkage map with resequencing-based 933,845 single-nucleotide polymorphism (SNP) markers covering a total genetic distance of 2483.17 cM. Nine quantitative trait loci (QTLs) for FOV7 resistance were identified, including qFOV7-D03-1 on chromosome D03 in two tests. Through a comparative analysis of gene expression and DNA sequence for predicted genes within the QTL region between the two parents and selected lines inoculated with FOV7, GB_D03G0217 encoding for a calmodulin (CaM)-like (CML) protein was identified as a candidate gene. A further analysis confirmed that the expression of GB_D03G0217 was suppressed, leading to increased disease severity in plants of the resistant parent with virus induced gene silencing (VIGS).

Highlights

Cotton (Gossypium spp.) is the most important fiber crop for the textile industry in the world
To identify quantitative trait locus (QTL) and discover candidate genes related to FOV race 7 (FOV7) resistance in G. barbadense, our study took advantage of the genome sequence information of G. barbadense to construct the first high-quality, high-density genetic linkage map in G. barbadense based on genome resequencing of 110 recombinant inbred lines (RILs) from a cross of FOV7-susceptible Xinhai 14 and FOV7-resistant 06-146
Results in skewness and kurtosis in each test showed that the disease severity rate (DSR) followed a normal distribution in the RIL population (Figure 1 and Table 1)

Summary

INTRODUCTION

Cotton (Gossypium spp.) is the most important fiber crop for the textile industry in the world. In the United States, a major dominant resistant gene (FOV1) to race 1 on chromosome D07 (c16) was identified and mapped in Pima S-7 (G. barbadense) using SSR markers (Wang and Roberts, 2006; Ulloa et al, 2011). To identify QTLs and discover candidate genes related to FOV7 resistance in G. barbadense, our study took advantage of the genome sequence information of G. barbadense to construct the first high-quality, high-density genetic linkage map in G. barbadense based on genome resequencing of 110 recombinant inbred lines (RILs) from a cross of FOV7-susceptible Xinhai 14 and FOV7-resistant 06-146. This study combined genome resequencing and RNA-seq in a RIL population, providing new knowledge for understanding the genetic and genomic basis of resistance to FOV7 in G. barbadense

MATERIALS AND METHODS

RESULTS

DISCUSSION

DATA AVAILABILITY STATEMENT