Drought resistance characters and variety development for rainfed lowland rice in Southeast Asia.
Use of drought response index for identification of drought tolerant genotypes in rainfed lowland rice.
Yield response of rice (Oryza sativa L.) genotypes to drought under rainfed lowland: 3.
A deep and thick root system has been thought advantageous for improved drought tolerance in the rainfed lowland ecosystem, based on extrapolation from experience with upland rice (O'Toole, 1982; and Fukai and Cooper, 1995).
Genetic improvement in the root system of rainfed lowland rice has been slow, partly because of the lack of a reliable screening system for phenotyping.
The potential for genetic improvement of the root system of rainfed lowland rice is discussed.
(2000) reported that CT9993, an upland adapted line, was slower in shoot and root growth compared with rainfed lowland genotypes under anaerobic lowland conditions.
The significance of phenotyping conditions for the identification of QTL for deep root traits, even in the absence of water stress, emphasizes the importance of choosing conditions comparable with the critical characteristics of the target environment in rainfed lowland fields (Wade et al., 1998).
The advantages of deeper root growth during progressive stress for water extraction from soil and for maintenance of plant growth were demonstrated in a pot system that simulated rainfed lowland conditions (Kamoshita et al., 2000).