Screening of Rice Germplasm Lines for Genetic Variability under Saline Conditions

Abstract

Development of salt-tolerant rice varieties is important for sustaining rice production in coastal saline soils. The present investigation evaluated genetic variability and identified promising rice genotypes under natural saline conditions. Twenty-eight genotypes were assessed during Kharif 2024 at the Agricultural Research Station, Machilipatnam, using an alpha-lattice design with two replications. Seedlings were transplanted into saline soil with pH 8.5 and electrical conductivity of 7.3 dSm⁻¹. Agronomic and physiological traits were recorded, including plant survival, flowering and maturity duration, plant height, ear-bearing tillers, panicle length, spikelet fertility, grain yield, salinity tolerance at seedling and reproductive stages and shoot Na⁺/K⁺ ratio. Analysis of variance showed significant differences among genotypes for all 11 traits at P < 0.01, indicating substantial variability under salinity. Estimates of GCV, PCV, heritability and genetic advance indicated useful scope for selection. Ear-bearing tillers, salinity scores at seedling and reproductive stages, and shoot Na⁺/K⁺ ratio showed comparatively high variability, while panicle length and grain yield showed moderate variability. Across the evaluated material, MCM 253-8-2-2, NIC 2-1-1B and C3-22-IR 1 exhibited superior salinity tolerance at both seedling and reproductive stages together with good yield performance. These lines represent promising material for further selection and use in breeding programmes aimed at improving rice performance under coastal saline conditions.