Although strides towards this goal began in the 1980s (Mohanty and Khush 1985; Mohanty and Chaudhary 1986; Haque et al. 1989), it was not until the mid-1990s that submergence tolerance from the FR13A-derived breeding line IR49830-7-1-2-2 was successfully introduced into productive short to intermediate stature lines (Mackill et al. 1993; Mishra et al. 1996).
SUB1 might also aid recovery from submergence as evident in the findings that the tolerant genotype M202-Sub1 displayed greater upregulation of mRNAs encoding antioxidant enzymes during submergence (Jung et al. 2010; Mustroph and Bailey-Serres 2010; Bailey-Serres et al. 2012) and showed less oxidative damage upon de-submergence than M202 (Fukao et al. 2011).
Computational results are presented for Froude numbers ranging from 3.2 to 8.2 and submergence factors ranging from 0.24 to 0.85.
These genotypes possess one or more of the adaptive traits required for the flood-prone ecosystem, which range from temporary submergence of 1 2 weeks to long period of stagnant water tolerance.
It should be noted that all of these RILs are already fixed for the SUB1 gene, which provides additional protection from complete submergence in both stagnant flooding and irrigated environments.
These cultivars are low yielder but possess one or more of the adaptive traits required for this ecosystem, which range from temporary submergence of one to two weeks, long periods of stagnant water, or daily tidal fluctuations that may sometimes cause complete submergence as in coastal areas.
Rice (Oryza sativa L ., unlike other cereals, can grow well in paddy fields and is highly tolerant of excess water stress, from either submergence (in which part or all of the plant is under water) or waterlogging (in which excess water in soil limits gas diffusion).
Because of its lighter weight, this newly introduced water will remain close to the surface, preventing the submergence of salty water from the south and so effectively shutting down the conveyor belt.
Rice landraces tolerant of up to 2 weeks of complete submergence were collected from farmers' fields in the 1950s.
Phenotyping of these SUB1A-2 varevealedrevealed a variable level of submergence tolerance ranging from about 4% to 40% plant survival after two weeks of submergence.
LOES facilitates escape from submergence stress and includes upward growth of leaves (hyponastic growth) and petiole/stem elongation initiated by ethylene accumulation (Jackson 2008).
