ASSESSING PRODUCTIVITY AND QUALITY POTENTIAL OF PROMISING NEWLY DEVELOPED RICE LINES UNDER WATER DEFICIT AND WELL-WATERED CONDITIONS

Water defecit is a crucial environmental stress that destructively limits rice growth and productivity, particularly under the current climate change. Consequently, developing drought-tolerant and high-yielding rice genotypes is essential to sustain rice production. This study aimed to investigate the genetic diversity of agronomic and qualitative characteristics among newly developed rice lines, comparing them to commercial checks under both water deficit and well-watered conditions. Thirteen newly advanced lines were collected from the F8 generation in the breeding program following a pedigree scheme. The studied advanced lines and five commercial cultivars were assessed under two water regimes: full irrigated (13000 m(3)/ha) and water stress (8500 m(3)/ha) conditions. The obtained results indicated highly significant variation among the evaluated genotypes in all studied agronomic and quality characters. Water deficit significantly reduced number of panicles per plant, 1000-grain weight, grain yield, hulling percentage, milling percentage, grain width, grain length, grain thickness, grain shape, hardness, elongation percentage, gel consistency, and gelatinization temperature (spreading and clearing), while broken and sterility percentage were significantly increased. Drought stress caused hindrance in panicle development and growth and hence reduced grain size and grain number as well as all quality characters. Cluster analysis, PC-biplot, and hierarchical clustering efficiently classified the evaluated genotypes based on the studied grain yield, yield components and quality traits. The evaluated genotypes were classified into distinct groups varying from drought-tolerant to moderately sensitive genotypes based on their agronomic performance and quality under drought stress. The advanced lines L5, L6, L7, L8, L10, L11, L12, and L13 displayed good agronomic and quality performance under drought stress. Moreover, lines L5, L6, L7, and L8 exhibited high-quality performance under drought stress. Generally, the genotypes L4, L5, L6, L7, L8, and L13 were identified as promising for improving yield traits and quality parameters under water deficit conditions. Subsequently, these identified genotypes could also be recommended for commercial cultivation under water deficit conditions. Furthermore, these genotypes could be exploited effectively to further improve of drought tolerance in rice through breeding programs to reinforce grain yield and quality under water shortage conditions, particularly under current climate change.