Field tolerance and recovery potential of sugarcane varieties subjected to drought

The present study was conducted to examine the effects of drought stress and recovery at formative phase of sugarcane varieties. Component traits of photosynthesis viz., chlorophyll fluorescence Fv/Fm, SPAD value and chlorophyll stability index were significantly reduced under drought stress. Accumulation of proline, enhanced lipid peroxidation, increased superoxide dismutase and peroxidase activity were observed in all varieties subjected to drought. After 30 days of rehydration, tolerant varieties recovered back to their normal physiological status in chlorophyll fluorescence Fv/Fm and nitrate reductase activity and membrane stability. There was a significant increase in cell membrane leakage during drought stress, however the tolerant varieties retained their cell wall integrity and recovered well after the stress. Among seven varieties, Co 06022 showed highest recovery as compared to other cultivars. Overall reduction in yield attributes and juice quality was observed under drought condition. The rates of reduction for most of the physio-biochemical traits such as chlorophyll fluorescence Fv/Fm, proline accumulation and antioxidant activities were higher in Co 8021, Co 775 and Co 97010. Also the recovery after drought stress was poor. However, drought tolerant varieties Co 06022, Co 99004, Co 06015 and Co 0315 were found better than others in maintaining their photosynthetic machinery, cell wall integrity and increased antioxidant activities that resulted in better recovery and relatively high yield and better juice quality.