Breeding for submergence tolerance in rice (Oryza sativa L.) and its management for flash flood in rainfed low land area: A review

Abstract

For rainfed low land paddy ecosystems which is supposed to withstand the sudden rise of water level for short period of time i.e. up to two weeks has been considered as the submergence tolerant. Proper screening and evaluation method are very important for cost effective and economic breeding procedures that will benefits the farmers. The agro morphological characters which are responsible for submergence tolerance; character association and path coefficient analysis will be very much useful to select them for further assessment. Hybrid rice will be another approach which could mitigate the flash flood constraints. Proper understanding of anatomical characters such as aerenchyma formation and changes of diameter of aerenchyma of root, shoot and leaf will be very much important for submergence tolerance if it is linked with genetic factors. Biochemical manipulation of different plant hormone such as gibberellic acid, abscisic acid and ethylene; enzyme like alcohol dehydrogenase synthesis; chlorophyll content and non structural carbohydrate content of shoot has significant role for enhancement of survival during underwater growth. Plant extracts or herbal crude product in the form of dry and wet treatments along with proper growth nutrients will be a holistic approach for sustainable and integrated agriculture and will be a tool for crop improvement in future breeding programme for submergence tolerance in rice.