Root Responses to Water Deficit under Rain-fed Lowland Rice

บทคัดย่อ

Drought is a major problem for rice grown under rainfed lowland conditions. The ability of rice plants to tolerate drought stress is associated with root system characters. However, genetic of root traits under lowland condition was uncertain. To determine the performance of root characteristic response to drought tolerance, a total of 220 double haploid lines, their parents (CT9993 and IR62266), and three standard checks (IR20, NSG19 and KDML105) were used in the experiments. The extent of genetic variation in root characters, relative water content, visual leaf rolling and drought injury under different intensities of water deficit were determined. Genotypes with short root were more dehydration tolerant than the longer root genotype, consequently more relatively high water content and delayed leaf rolling and senescence under severe water deficit.