Evaluation of forage sorghum genotypes for chlorophyll content under salt stress

Salinity is a major abiotic factor in arid and semi arid tropics that affects plant growth by creating osmotic stress, ion toxicity, mineral deficiencies and physiological and biochemical perturbations. Eleven genotypes were evaluated for chlorophyll content in forage sorghum under various salinity levels viz. control C, EC1 (4.0 dSm ), EC2 (8.0 dSm ) and EC3 (12.0 dSm ). Thus the present experiment was planned with the objective to study effect of salinity stress on chlorophyll content of forage sorghum genotypes, COFS 29, SSG 59-3, SSG 9, HC 136, HC 308, HJ 541, S 437-1, S 490, S 540, IS 2389 and IS 3237 under different salinity conditions i.e. control C, EC1 (4.0 dSm ), EC2 (8.0 dSm ) and EC3 (12.0 dSm ). Chlorophyll a, Chlorophyll b and total Chlorophyll content (mg/g, fresh wt.) among different genotypes varied from 0.94 (SSG 9; EC3) to 2.0 (SSG 59-3; C), 0.30 (S 437-1; EC3) to 0.64 (SSG 59-3; C) and 1.28 (SSG 9; EC3) to 2.64 (SSG 59-3; C) respectively. Lower and higher total chlorophyll content (mg/g, fresh wt.) at highest level of salinity i.e. EC3 (12.0 dSm-1) was observed in SSG 9 (1.28) and SSG 59-3 (1.98), respectively and it is concluded that chlorophyll content in sorghum leaves decreased with the increase in the salinity levels in the soil.