Root study of traditional rice cultivars and IR64 introgressed lines for vegetative stage drought

摘要

Drought is major problem for rice grown under rainfed upland conditions. Progress in breeding for drought resistance has been slow; mainly because of the wide range of water stress environments found in rice growing areas; drought conditions differ intime, intensity, and hydrology (Fukai and Cooper et al., 1994). From the perspective of a plant physiologist agronomist, plant water status has a major impact on plant function and adoptive processes in the plant under water limited environments. Several studies in the past reported that the major control of plant water status in crop plants subject to drought is exerted mainly by constitutive traits like root length, plant phenology, and leaf surface properties (Bloom, 2000). These traits may help tomaintain high relative water content, and tend to retain higher leaf area and low leaf rolling. Traditional cultivars or landraces have unique tolerance strategies appropriate to specific growing condition. There are several putative traits that confer drought resistance in rice, therefore, this investigation was designed to identify morphophysiological traits and the inter -ssociation with drought tolerance in target environment.