Molecular identification of restorers for <i>Rf3</i> and <i>Rf4</i> fertility genes in rice (<i>Oryza sativa</i> L.) using traditional and high yielding varieties of Kerala

Hybrid rice technology, offering significant yield advantages, is a promising solution for addressing the global food security challenges. Fertility restorer genes Rf3 and Rf4 are pivotal for advancing hybrid rice breeding initiatives. Owing to the enormous variability observed in the varieties and landraces in Kerala, India, possibility of finding new alleles of important genes from these varieties is hypothesised. Finding new alleles of Rf3 and Rf4 genes will be extensively useful in hybrid rice technology. This work examined 152 rice varieties of Kerala, encompassing both High Yielding Varieties (HYVs) and Traditional Rice Varieties (TRVs), to mine the novel alleles of Rf3 and Rf4. The varieties were screened using the molecular markers functionally linked to these genes. A distinct distribution of allelic combinations, with Rf4 displaying higher prevalence (52%) compared to Rf3 (32%) was observed. Twenty-two varieties were identified as putative restorers, while forty-eight served as maintainers, offering a precise direction for selecting the parental lines with superior restoration potential. The findings highlight the pivotal role of Rf4 in governing fertility restoration, emphasizing its critical significance for optimizing hybrid seed production.