Identification of molecular markers associated with genic male sterility in tetraploid cotton (Gossypium hirsutum L.) through bulk segregant analysis using a cotton SNP 63K array

Genic male sterility (GMS) is one of the most important economic traits for cotton (Gossypium hirsutum L.) hybrid seed production. The GMS trait conferred by two recessive alleles ms5 and ms6 in homozygous constitution is widely used for cotton hybrid seed production in India. Identification of molecular markers closely linked to the ms5 and ms6 alleles would be useful in effective transferring in a short time male-sterility genes into cultivars or elite lines using marker-assisted backcrossing. Here, we describe a quick method to identify markers for GMS genes using bulk segregant analysis (BSA) in the interspecific (G. hirsutum × G. hirsutum) biparental population. The parents and bulks were genotyped with a cotton single nucleotide polymorphism (SNP) 63K array that contains 63 058 SNP markers including 45 104 intraspecific and 17 954 interspecific SNP markers. Four SNP markers were found to be linked with the Ms5 and Ms6 genes. The markers i23493Gh and i46470Gh linked with the Ms5 gene, and other two markers i08605Gh and i08573Gh linked with the Ms6 gene are located on chromosome 12 and 26, respectively. A simple and cost effective tetra-primer amplification refractory mutation system PCR (tetra-primer ARMS-PCR) assay was optimized for screening a large number of breeding samples with the identified SNP markers in a short time. The molecular markers developed in this study will facilitate the marker-assisted selection (MAS) and accelerate the development of new GMS lines to use in cotton hybrid seed production.