Novel Rice (Oryza sativa L.) Genotypes Tolerant to Combined Effect of Submergence and Salt Stress

The implications of both complete and partial submergence with saline water on growth and survival of different rice genotypes were investigated. The study showed that among the 199 genotypes, only five genotypes namely IC-459744, IC-469712, IC-464746, IC-459649 and IC-17024 were tolerant to both complete (plants under water) and partial submergence (water depth 45±5 cm) with saline water (12 dS m⁻¹). The association of Chlorophyll a, Chlorophyll b, total Chlorophyll, normalized difference vegetative index (NDVI) and photochemical reflectance index (PRI) with score under partial submergence with salt stress were highly negatively signifi cant (p<0.001***). Biplot derived from principal component analysis showed that accessions such as IC-459744 and IC-459649, tolerant to both complete and partial submergence with salty water were in the same quarter where PRI was located with long vertex. The genotypes identified in this investigation have great potential as unique genetic resources for utilization in crop improvement programmes.