Vol. 10, Issue 10 (2021)

Author(s):
Shahina Perween, E Kokiladevi, KK Kumar, S Varanavasiappan, V Ravichandran, D Sudhakar and L Arul

Abstract:
Soil salinity is a great challenge in rice cultivation which reduces the plant growth and yield. A successful breeding programme requires an appropriate screening strategy to identify the best genotypes/recombinants possessing improved salt tolerance capabilities. In the present study, we have screened the performance of 6 selected rice genotypes (Pokkali, Kuthir, Mundan, Odiyan, ASD16, IR29) for selected root parameters viz., morphological, architectural, physiological and anatomical under salinity stress (75 mM NaCl) in hydroponics set up. Phenotyping for salt tolerance was scored based on IRRIs Standard Evaluation Score (SES). The salt tolerant rice genotypes (Pokkali and Kuthir) with low SES values had maintained a low Na⁺/K⁺ ratio as against the salt susceptible genotypes (ASD16 and IR29). The moderately tolerant genotypes (Mundan and Odiyan) were found to have an intermediary Na⁺/ K⁺ ratio. There was a strong positive correlation between the SES and root Na⁺/K⁺ ratio, a strong negative correlation between the shoot length and root Na⁺/ K⁺ ratio and, between the root length and root Na⁺/K⁺ ratio. Root architectural traits viz., the maximum number of roots and root network length were significantly affected under salt stress as compared to normal condition invariably in all the rice genotypes.