Unraveling the genetic and molecular bases of heterosis in a TGMS-based two-line rice hybrid derived F2 segregating population

In the absence of system-specific reference genomes and transcriptomic resources for two-line rice hybrids, candidate gene identification was conducted using the Nipponbare reference genome and publicly available expression datasets. Several biologically relevant genes were prioritized within major QTL intervals, including SPP (sucrose-phosphate phosphatase), GW2 (grain width regulator), DEP1 (panicle architecture), and OsCCaMK (calcium/calmodulin-dependent protein kinase), supported by positional evidence and tissue-specific expression patterns.Overall, this study provides a high-resolution dissection of heterosis-associated genomic regions in a TGMS-derived F₂ segregating population and delivers valuable candidate loci for marker-assisted selection and functional validation. These findings advance our understanding of heterosis in two-line hybrid rice and offer practical insights for the development of next-generation high-yielding hybrids.