29 BREEDING FOR WATERLOGGING TOLERANCE IN SUGARCANE K. Chandran 1* , R. Gomathi 2 , M. Nisha 1 and R. Arun kumar 2 Abstract Excess moisture stress/waterlogging stress is one of the major constrains in sugarcane agriculture. About 2.2 Lakh hectares sugarcane is getting affected by waterlogging across the sugarcane growing states in the country. Though waterlogging management may offer relief to short term stress, a permanent solution can be realized only through imparting resistance/tolerance to varieties though conventional breeding or biotechnological means. Heavy rainfall and poor drainage of water from the soil, inundation by the overfowing rivers and excessive irrigation are the major causes of waterlogging. Waterlogging stress affect almost all stages of crop growth in sugarcane; germination, tillering, and grand growth period and thereby reducing the biomass yield and quality. Several genotypes including breeding lines, commercial hybrids, Saccharum species and distantly related genera are available as source of tolerance and the breeding approaches need to be directed towards developing varieties with waterlogging tolerance by conventional or biotechnological means. This paper reviews the response of sugarcane plant to waterlogging stress, the availability of gene pool for waterlogging tolerance, breeding approaches and selection parameters for developing waterlogging tolerant varieties. Key words: Sugarcane, waterlogging, anaerobic respiration, physiological markers, breeding, stress tolerance K. Chandran, R. Gomathi, M. Nisha and R. Arun kumar 1 ICAR-Sugarcane Breeding Institute Research Centre, Civil Station (PO), Kannur (Kerala)-670 002, India. 2 Crop Production Division, ICAR-Sugarcane Breeding Institute, Coimbatore-641 007, Tamil Nadu, India. *Corresponding author: chandranksd62@gmail.com REVIEW ARTICLE Introduction Sugarcane is the second most important industrial crop in the country occupying about 5 million hectares of area with a production of 376.9 mt which support the production of 32.38 mt of sugar (Anonymous, 2019). About 5 million farmers are involved in the cultivation of sugarcane and sugar industry contributes signifcantly to the rural economy by providing employment for nearly 4% of the rural population directly or indirectly (http://www.sugarcane.res.in /images/sbi/ article/ sbi_vision_ 2050.pdf). The sugarcane production is hindered by several biotic and abiotic stresses. Excess moisture stress is one of the abiotic stresses that signifcantly affect the sugarcane production, productivity and quality of the produce. Waterlogging stress occurs when the water table rises to an extent by which the root zone of the crop get saturated which results in restriction of root zone aeration. For optimum growth of sugarcane the water table should be maintained below one meter (Moore 1987). Waterlogged situation is a major challenge to sugarcane agriculture, and about 2.2 lakh hectares are affected by food/ waterlogging. The situations is very severe in parts of UP, Bihar, Odissa, Maharashtra, coastal areas of Andhra Pradesh and Karnataka (Nair 2012) and continue to increase in the present scenario of rapid climate change. Sugarcane cultivation is affected by waterlogging mainly during monsoon period. Heavy rainfall and poor drainage of water from the soil, inundation by the overfowing rivers and excessive irrigation are the major causes of waterlogging and it affect almost all stages of crop growth; germination, tillering, and grand growth period and thereby reducing the biomass yield and Journal of Sugarcane Research (2019) 9 (1) : 29 - 44