Physiological responses of commercial sugarcane ( Saccharum spp. hybrids) varieties to moisture deficit stress tolerance

Physiological responses of 52 commercial sugarcane varieties ( Saccharum sp. hybrids) were studied by withholding irrigation after 2 months of growth under green house conditions. Based on the time taken for appearance of wilting symptoms after exposure to moisture deficit stress, varieties were grouped into different groups and susceptible (Co 775 and Co 99010) and highly tolerant (Co 94008, CoT 8201 and ISH 100) varieties were identified. Physiological parameters such as proline, RWC and chlorophyll content were measured 8 days after stress induction and the changes were recorded under unstressed and stressed conditions. RWC and chlorophyll content under stress condition were positively correlated with the time taken for appearance of wilting symptoms. Reduction in RWC and chlorophyll content under stress condition was negatively correlated with the time taken for appearance of wilting symptoms. Hence, RWC and chlorophyll content can be suggested as a good indicator of stress tolerance.