An Overview on Submergence Tolerance in Rice: Farmers' Wisdom and Amazing Science

摘要

Rice is often the only crop that can be grown in flood prone ecosystems whose productivity is greatly affected depending on the intensity and duration of rainfall, the quality, the depth and the duration of standing water, flooding frequency, times offlooding, soil type and topography. Though India occupies the largest area under rainfed lowlands and flood prone ecosystem in Southeast Asia, the problem is grave in Thailand, Bangladesh, Indonesia, Vietnam, Myanmar and different African countries. Theproblem is now much grave due the resilience of an unprecedented combination of climate change and associated disturbances. Rice landraces tolerant of up to 14 days of complete submergence were collected from farmers fields in the 1950s. Success in finemapping of Submergencel (Subl), a robust quantitative trait locus from the submergence tolerant FR13A landrace, has enabled marker-assisted breeding of high-yielding rice capable of enduring transient-complete submergence. Water-proof rice is now a reality and several cultivars tolerant to complete submergence have been released in different Southeast Asian countries including India. New era of research of high rise rice is gradually opening up due to the discovery of new genes Snorkel 1 and Snorkel 2for deep water flood tolerance that will be used in enhancing rice productivity. Post-genomic tools are in very much use to unearth the wealth of rice germplasm. The knowledge of the genetics high use response is discussed. There is a need to accomplishthe challenges ahead to develop multiple abiotic stress tolerant rice plants so that farmers could get more and more water-proof rice and undoubtedly could produce more food from marginalized and fragile farm land.