Screening and classification of cowpea genotypes for salt tolerance duringgermination

Twenty-five cowpea genotypes were tested to determine salt tolerance during germination to three salinity levels (0, 85, and 170 mM NaCl). Germination percentage decreased as salinity increased. Salt concentration affects cow pea genotypes seeds by delaying start of germination. Salinity lowered both germination rate and germination percentage. Two criteria were used to cla ssify genotypes as tolerant: 1) genotypes with more than 75% germination co mpared with the control at 170 mM NaCl and genotypes with more than 90% ger mination compared with the control at 85 mM NaCl, and 2) genotypes with mor e than 40% germination compared with the control at 170 mM NaCl and more th an 75% compared with the control at 85 mM NaCl. Tolerant genotypes were UCR 109 CB3, H-8-27, UCR 158 CB88, UCR 188 CB5, and CB 46 from University of C alifornia Riverside and Paceno from Mexico. The criterion for sensitivity w as less than 30% germination with respect to the control at 170 mM NaCl and less than 15% germination with respect to the control at 170 mM NaCl. Sens itive genotypes were IT96D-733, IT89KD-391, IT95K-1088-4, IT95K-1090-12, an d IT90K-277-2 from IITA, Nigeria, and Sonorense from Mexico. UCR 109 CB3 wa s the most salt tolerant genotype, while H8-8-27 UCR 158 CB88, Paceno, UCR 118 CB5, CB 46 and IT89KD-288 were intermediate in salt tolerance. The rest were considered salt-sensitive genotypes.