INCONSISTENCY IN SALT TOLERANCE OF SOME WHEAT (TRITICUM AESTIVIUM L.) GENOTYPES EVALUATED UNDER VARIOUS GROWING ENVIRONMENTS

Wheat genotypes were evaluated for their salt tolerance under water culture at early seedling stage, gravel culture at vegetative & maturity stage and under natural saline field condition at maturity. Ten newly developed wheat genotypes were included along with local check (LU-26s). The tested wheat genotypes were found more sensitive at vegetative and maturity than at early seedling stage. At early seedling stage 4 genotypes (NIA-AS-14-2, NIA-AS-14-5, NIA-AS-14-10 and LU-26s) fell into the tolerant category (i.e., STI > 50%) and one (NIA-AS-14-1) as sensitive (S) (STI < 30%). The response of wheat genotypes was bit different under gravel culture at maturity stage, where the genotypes LU-26s, NIA-AS-14-2 and NIA-AS-14-8 performed well. The genotype LU-26s, NIA-AS-14-1, NIA-AS-14-2, NIA-AS-14-4, NIA-AS-14-7 and NIA-AS-14-8, showed better performance in all the parameters and categorized as tolerant (T). Least performance under gravel culture was observed by NIA-AS-14-6. The results with respect to the performance under natural saline field conditions showed that the genotypes NIA-AS-14-1, NIA-AS-14-4, NIA-AS-14-9 and NIA-AS-14-10, along with local check (LU-26s), had better tolerance at medium to highly saline patches. The genotypes were also evaluated for their physiological performance at early seedling and vegetative (at the time of flowering) stage. The physiological traits studied were solute contents (organic and inorganic). Tolerant genotypes showed dual types of behavior in case of Na+ accumulation (i.e. NIA-AS-14-1, NIA-AS-14-2 and LU-26s (local check) showed low Na+ accumulating pattern, where as NIA-AS-14-8 and NIA-AS-14-9 showed higher accumulating trend under saline environments. Accumulation of proline was also low in low Na+ accumulating genotypes. The overall investigations showed that screening at early growth stage (2-4 weeks) was more convenient than at vegetative or at maturity, but its reliability might be questioned as most of the genotypes were tolerant at early seedling stage but showed sensitivity during vegetative and at maturity during grain filling stage. Therefore, it necessitates that selection of salt tolerant genotypes under different environments before recommending a genotype as tolerant. In the present investigation three genotypes (NIA-AS-14-2 NIA-AS-14-4 and NIA-AS-14-10) and a local check LU-26s were indentified to have the potential to perform economically under medium to high saline soils.