Integrated GWAS, BSA-seq, and RNA-seq analyses to identify candidate genes associated with male fertility trait in peach

Abstract

Male sterility in peach (Prunus persica L.), characterized by the absence of fertile pollen grains in the anther, is determined by a recessive allele in homozygosis of the major gene located on chromosome 6. Developing tightly linked molecular markers can help identify appropriate peach parents or male-sterile plants for early culling in segregating progenies, thereby increasing breeding efficiency. In this study, we performed comprehensive research integrating genome-wide association study, bulked segregant analysis, and tissue-specific transcriptome sequencing for precisely characterizing the genes associated with male sterility and fertility in peach. We identified the candidate gene Prupe.6G027000, which encodes an ATP-binding cassette transporter G family member 26 (ABCG26), as a reliable candidate for controlling the targeted traits, as indicated by gene expression profiling and validated by quantitative real-time polymerase chain reaction, in situ hybridization, and virus-induced gene silencing. Prupe.6G027000 was transcribed preferentially on the tapetum and microspore surface, and its transient silencing caused severe pollen abortion in peach. The genotypes of nonsynonymous single-nucleotide variation (T > C) harbored in the coding region of Prupe.6G027000 exhibited approximately 96.2% consistency with male fertile or sterile phenotype in 579 peach accessions. These findings lay the foundation for dissecting the genetic basis of male fertility traits, and facilitating the establishment of a marker-assisted selection system in peaches.