Changes in Morphological, Physiological and Chemical Characteristics of Sunflower (Helianthus annuus L.) Genotypes Induced by Salt Stress

Investigations on characterization of various sunflower genotypes regarding their morphological, physiological, chemical parameters, seed oil and its quality through studying fatty acid composition under different salinity levels was carried out at Saline Agriculture Research Centre, University of Agriculture, Faisalabad. Seeds of four sunflower genotypes (FH-385, FH-352, FH-106 and FH-259) were sown in lysimeter and three salinity levels (control, 8dS m-1 and 16dSm-1) were developed by using NaCl salt. Results revealed that salinity stress drastically affected the morphological, physiological, chemical parameters and quantity and quality of seed oil in all sunflower genotypes under all levels of salinity stress. Studies further exhibited that sunflower genotype FH- 385 was found leading salt resistant genotype by showing less reduction in all plant growth parameters i.e. plant height (25%), shoot fresh weight (30%), SPAD value (13%), relative water content (17%),flower weight (32%), flower diameter (14%), photosynthetic rate (8%), transpiration rate (28%), internal CO2concentration (24%), stomatal conductance (32%), seed oil (35%), linoleic acid (32%) and K+/Na+ ratio (73%) relative to percent of their control at high level of salinity (16dSm-1). The results of our experiment clearly indicated that the sunflower genotypes FH-385 was the most salt tolerant followed by FH-352 and FH-259 while FH-106 was the most salt sensitive genotype.