Harnessing Seed Traits to Combat Preharvest Sprouting in Rice Varieties

Rice (Oryza sativa) sustains nearly half of the global population as a staple crop, and the escalating population underscores the imperative for improved productivity. However, climate change poses substantial challenges, with unpredictable rainfall and high humidity during harvest contributing to preharvest sprouting (PHS). PHS is characterized by the premature germination of grains within the panicle due to adverse environmental conditions, resulting in significant economic losses and compromised grain quality. Developing varieties resistant to PHS is paramount for ensuring rice production resilience. The study assessed nine rice varieties under artificial PHS conditions at 35 and 40 days after flowering over treatment periods of 3, 5, and 7 days. The resistant varieties exhibited no germination under artificial PHS, while the susceptible varieties showed germination rates ranging from 80 to 100%. Moisture imbibition capacity emerged as a pivotal determinant of PHS susceptibility, with reduced water uptake delaying germination. Distinct seed traits, such as red seed coat and red pericarp colors, were strongly correlated with PHS resistance, whereas white pericarp and light-yellow seed coats characterized susceptibility. Furthermore, resistant varieties demonstrated high carotenoid content, a biochemical marker associated with enhanced seed dormancy. PHS adversely affects agronomic traits, including grain yield. However, resistant genotypes displayed superior performance across these metrics compared to their susceptible counterparts These findings underscore the potential of resistant varieties as valuable genetic resources for breeding PHS-tolerant rice, thereby mitigating yield losses and stabilizing rice productivity under changing climatic conditions.