DefinePK

Abstract

The research work was conducted to elucidate the heat acclimation potential of two promising cotton cultivars Rehmani and S-12 . The plants were hardened for 1 to 7 days at 43ºC for 2h. After every hardening treatment the leaves were heat stressed at 45ºC for 2h. The chlorophyll fluorescence (Fv/Fm) ratio was recorded at pre-incubation, during heat stress and recovery after heat stress. The results showed that cv. Rehmani gave better results only after 1 day hardening treatment but after 2 to 7 days treatments the Fv/Fm ratio declined. However, cultivar S-12 showed good acclimation response as the treatment days were increased to 7-days hardening treatment the Fv/Fm ratio increased to 83% of the control treatment (no hardening).