Appraisal of Some Physiological Selection Criteria for Evaluation of Salt Tolerance in Canola (BRASSICA NAPUS L.)

In order to examine whether growth of ten genetically diverse canola (Brassica napus) lines under salt stress is positively associated with their rate of photosynthesis and other physiological traits, a greenhouse experiment was conducted. Six week-old hydroponically grown plants of canola cultivars were subjected to 0 (control), 50,100, 150 and 200 mM for five weeks.When plants are grown under saline conditions, photosynthetic activity decreases leading to reduced plant growth. The salinity reduced total dry matter and also chlorophyll content as the salt level increased. The lines Dunkeld followed by Hayola 401 were found to be salt tolerant and Olga and Sponsor lines salt sensitive with regard to total dry matter production. Stomatal conductance was found to be lower in the salt sensitive line Olga, and the Dunkeld was highest followed by Hayola 401.Furthermore, photochemical efficiency of PS2 (Fv/Fm), photochemical quenching coefficient (qP), and chlorophyll content (SPAD value) were also reduced (P < 0. 01) by salt stress. A close correlation found between photochemical efficiency of PS2 (Fv/Fm) and photochemical quenching coefficient (qP).