Evaluation of Clusterbean (Cyamopsis tetragonoloba L. Taub.) Genotypes for Saline Irrigation Water Stress Conditions

Abstract

The present study was conducted at the College of Agriculture, Mandor, Jodhpur, to assess genetic variability, heritability and genetic advance in 20 genotypes grown under three salinity levels: normal irrigation (S0), moderate salinity at 5 dS/m (S1) and high salinity at 10 dS/m (S2). To assess genetic variability parameters in saline irrigation water. In this pot culture has been used and saline irrigation treatment has given to the 20 genotypes when irrigation required. Under non stress conditions (S0) growth and biomass traits exhibited moderate phenotypic and genotypic variability indicating stable expression. High heritability and high genetic advance in traits such as total free amino acids (h2 = 99.87 and GAM = 120.8) and proline content (h2 = 99.56 and GAM = 90.68) along with moderate genetic advance for chlorophyll content (h2 = 98.86 and GAM = 57.83) and root length (h2 = 39.12 and GAM = 98.63) represent predominant additive gene action under normal irrigation. Under moderate salinity (S1) increased GCV and PCV have been recorded particularly for biochemical and physiological parameters such as catalase, peroxidase, relative water content and membrane stability index. These increases indicated enhanced genetic divergence under stress. High heritability with substantial genetic advance in proline (h2 = 99.94 and GAM = 181.93) and antioxidant enzymes. High salinity (S2) produced the greatest variability across morphological, physiological and biochemical traits. Proline (GCV = 150.5 and PCV = 150.51), antioxidant enzymes and phenol (GCV = 94.77 and PCV = 101.89) showed maximum GCV and PCV confirming strong genotypic differentiation. Across all salinity levels, growth and chlorophyll content decreased while stress related traits increased. Genotypes HG-2-20, RGC-1031, RGr-18-1, HG-365, GG-2, RGC-589 and RGC-601 exhibited superior tolerance and are promising for cultivation and breeding under saline conditions.