Construction of a Genetic Map by Resequencing and Specific Locus Amplified Fragment sequencing (SLAF-seq) for QTL fine mapping of plant height in upland cotton (Gossypium hirsutum L.)

Abstract

Background: Gossypium hirsutum (upland cotton), the most widely cultivated cotton species in the world, is an important raw material for the textile industry. Using high-throughput sequencing to construct high-density genetic maps can be widely used in quantitative trait locus (QTL) mapping and molecular marker-assisted breeding.Results: In this study, an F2 population was used to construct a genetic map by parental resequencing and progeny SLAF-seq. The F2 population consisted of Gossypium hirsutum L. cultivars: CCRI 49 and 396289. The genetic map contained 4,607 single nucleotide polymorphisms markers, which overlapped a total length of 3,063.4 cM with an average genetic distance of 0.898 cM between adjacent markers. A high-density genetic map was used to map the QTLs of plant height in four environments. 16 QTLs were obtained, which could explain 2.07%–19.04% of the phenotypic variation. A total of 1,028 candidate genes were identified in the confidence interval and were categorized according to function through cluster of orthologous groups analysis, gene ntology analysis, and Kyoto Encyclopedia of Genes and Genomes analysis. Within the QTLs confidence interval, the D05 chromosome(ChrD05) was finely mapped using Mutmap-like strategy, and the reliability was validated by qRT-PCR of 18 candidate genes . Finally, we obtained 14 candidate genes that are most likely to be related to plant height.Conclusions: This study provides a successful application of parental sequencing and progeny SLAF-seq strategy in the genetic map of upland cotton in an F2 population. This study provides theoretical support for molecular marker-assisted breeding and plant height-heterosis in upland cotton and provides a fine mapping scheme for QTLs. In addition, the combination of multiple analytical methods also provided a solution for QTL fine mapping.