Assessment of waterlogging induced physio-biochemical changes in sugarcane varieties and its association with waterlogging tolerance

ABSTRACT

Aim: The aim of the present investigation was to study the effect of waterlogging on growth and physiological behaviour of sugarcane varieties, and to evaluate these in relation to waterlogging tolerance to identify reliable physiological parameters for screening sugarcane genotypes for waterlogging tolerance.. Methodology: Ten sugarcane varieties including four tolerant and one sensitive were planted under waterlogged and non waterlogged (control) conditions. Waterlogging was imposed for 70 days at the crop age of 120 days, thereafter water was completely drained. Based on relative cane weight (% waterlogged/control), the ranking of varieties was done for waterlogging tolerance. Changes in cane weight, stalk growth rate, internode length, chlorophyll stability index and antioxidant enzyme activity were measured at the end of waterlogging. Leaf samples were analysed for nitrogen, phosphorus and potassium content. Correlation between waterlogging tolerance and different traits was assessed. Results: Based on relative cane weight (% waterlogged/control), CoLk 94184 was found to be the most waterlogging tolerant variety while CoJ 64 the most sensitive. Waterlogging remarkably reduced stalk growth rate and a significant positive correlation was found between waterlogging tolerance and stalk growth rate during waterlogging. The average internode length of sugarcane varieties increased by 11% in waterlogging as compared to control. Tolerant varieties had high chlorophyll stability index than sensitive one showing that tolerant varieties had less chlorosis in waterlogging. Waterlogging caused a significant increase in antioxidant enzyme activity of catalase, peroxidase and superoxide dismutase, however these increase were higher in tolerant varieties. Waterlogging induced severe deficiencies of N, P and K in sugarcane; the leaf N and K concentration were below critical deficiency level. A strong positive correlation was found between leaf K content and waterlogging tolerance. Interpretation: Stalk growth rate, chlorophyll stability index and leaf potassium concentration during waterlogging were identified as efficient physiological traits for screening the sugarcane varieties for waterlogging tolerance.