Heterotic Analysis (Oryza sativa L.) in Drought Tolerant Rice Accessions

Abstract

Water-deficit stress tolerance in rice is important for maintaining stable yield, especially under rain-fed ecosystem. After a thorough drought-tolerance screening of 200 rice genotypes from DBT, Network Rice Project in our previous study, 19 rice lines were selected for drought tolerance capacity. Six randomly chosen rice accessions out of these 19 rice accessions were further used for creation of F1 Hybrids for heterosis study. The study investigates the heterosis effects on key agronomic traits in rice hybrids, including days to 50% flowering, plant height, number of effective tillers per plant, spikelet fertility, grain yield per plant, and 100-grain weight. Analysis reveals diverse heterotic effects across hybrid combinations, with some hybrids exhibiting significant negative heterosis for traits like days to flowering and plant height, indicating potential for early maturation and dwarfism, respectively. Conversely, positive heterosis is observed in traits such as number of effective tillers, spikelet fertility, grain yield, and 100-grain weight, highlighting the potential for enhanced productivity. Notably, certain hybrids consistently display strong positive heterosis across multiple traits, suggesting their suitability for breeding programs aimed at improving overall yield and agronomic performance.