Non-redundancy of Rice Mutant Library for Male Gametogenesis Confirmed by Bulked Segregants Analysis Using Illumina BeadsArray

Mutant resources play a crucial role in unraveling the genetic network controlling traits of interest. In this study, we focused on pollen-sterile mutants as important genetic resources for understanding the genetic regulation of male gametogenesis. We employed high-throughput genotyping technologies using Illumina BeadArray to map the responsible genes for male gametogenesis in rice; four SPOROPHYTIC POLLEN STERILITY (SPS2, SPS3, SPS4, SPS7) and four GAMETOPHYTIC POLLEN STERILITY (GPS1, GPS2, GPS9, GPS10). Using 287 single nucleotide polymorphism (SNP) markers, we detected polymorphisms between the japonica cultivar Taichung 65 (T65) and Hinohikari. Bulked segregant analysis (BSA) based on DNA marker analysis was performed to identify candidate markers tightly linked to the causal genes. The analysis revealed candidate markers for each mutant line, such as Mk240 for SPS2 and Mk94 and Mk126 for GPS1. Linkage mapping using the PCR-based markers confirmed the map positions of these candidate markers. Our study demonstrates the utility of high-throughput genotyping technologies combined with BSA for the genetic characterization of mutant stocks. The identified candidate markers provide valuable resources for future studies aiming to understand the molecular mechanisms underlying pollen development and male gametogenesis in rice. The systematic gathering and reduction of redundancy in pollen sterile mutants are essential for a comprehensive understanding of the molecular networks involved in post-meiotic male gametogenesis.