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Screening of Genotypes for Drought Tolerance Using PEG 6000 in Different Landraces of Rice (Oryza sativa L.)

Drought stress restricts crop productivity in the face of climate change. The loss of water resources for food production is a global concern as the world's population continues to expand. Drought-tolerant cultivars must be developed to assure food and nutritional security. The drought response of rice landraces is poorly understood. Rice genotypes Sengalpattu sirumani, Mappillai sambha, N22, and IR64 were used to standardize drought stress using polyethylene glycol (PEG 6000). The PEG 6000 concentration which caused 50% mortality in the experiment was -0.8 MPa and this was used to impose drought stress to evaluate the total set of rice genotypes in the laboratory of the Department of Crop Physiology, Adhiparasakthi Agricultural College. The experiments were carried out by a factorial randomized complete block design in five replications. Germination percentage, shoot length, root length, vigor index, chlorophyll content, and proline content were used to screen and select the rice landraces. The rice landraces Sengalpattu sirumani, Poongar, Karuppukavuni, and Iluppaipoo sambha recorded higher germination percentages under drought stress conditions. It was observed from the physiological and biochemical parameters in the present study that the landraces Sengalpattu sirumani, Poongar, Karuppukavuni, and Iluppaipoo sambha withstood drought stress at the seedling stage. Furthermore, These four rice landraces could be used as donor parents in the breeding program to develop drought-tolerant rice varieties.