Assessment of Genetic Variability, Heritability and Genetic Gain for Waterlogging Tolerance Traits in Soybean Genotypes

Abstract

Waterlogging is an important abiotic stress that can reduce soybean growth, nodulation, survival and seed yield under poorly drained field conditions. The present study evaluated variation among soybean genotypes for selected waterlogging tolerance traits under field conditions. Forty-five soybean genotypes were assessed in a randomised block design under waterlogged conditions. Observations were recorded for plant survival rate, stress tolerance index, reduction in root nodule dry weight per plant, reduction in seed yield per plant, waterlogging tolerance coefficient, seed yield per plant and biological yield per plant. The genotypes showed measurable variation for all assessed traits. Plant survival rate ranged from 83% to 89%, while the stress tolerance index varied from 60% to 79%. Reduction in root nodule dry weight per plant ranged from 25.40% to 44.19%, and reduction in seed yield per plant ranged from 18.85% to 40.52%. Waterlogging tolerance coefficient values ranged from 62.64 to 74.01. Seed yield per plant under waterlogged conditions varied from 9.1 to 15.8 g, while biological yield per plant ranged from 29 to 49 g. NRC 127 recorded the highest seed yield per plant and also showed high plant survival and stress tolerance index values. NRC 142, JS 21-72, NRC 258, DS 1570, AMS 2021-3 and RSC 1172 also showed favourable performance for one or more waterlogging tolerance-related traits. The results indicate useful variability among the evaluated soybean genotypes. These genotypes may be considered for further screening and use in breeding programmes after confirmation across seasons and locations.