Morpho-physiological Responses of Cotton (Gossypium hirsutum) to Salt Stress

Soil salinity is a big threat for crop productivity. To assess the response of cotton (Gossypium hirsutum L.) to salinity stress, 10 cotton genotypes (CIM-446, CIM-506, RH-510, MNH-770, FH-2007, BH-118, FH-87, CIM-496, FH-901 & CIM-473) were grown in full strength Hoagland's nutrients solutions containing 50,100 and 200 mM NaCl. Root-medium applied salt stress significantly reduced plant height, fresh and dry weights, and gas exchange characteristics of all cotton genotypes. This reduction was the maximum at highest level of salt stress viz. 200 mM NaCl as compared to lower i.e., 50 or 100 mM. A considerable variation in salt tolerance was observed among all ten cultivars with respect to above mentioned morphological and physiological attributes. Overall on the basis of better growth performance under saline conditions, cultivars RH-510, BH-118 and FH-87 were ranked as relatively salt tolerant; whereas CIM-446 and CIM-506 salt sensitive, while others were moderately salt sensitive. Shoot dry mass and photosynthetic rate can be used as markers of salt tolerance in cotton. (C) 2012 Friends Science Publishers