Identifying Donors for Anaerobic Germination Tolerance and Direct Seeded Rice Cultivation by Exploring Seed and Seedling Traits

Abstract

Background: Anaerobic conditions in waterlogged soil affect germination rate significantly reducing rice yields. Under wet direct seeded condition, only limited availability of rice genotypes are suitable for anaerobic germination. So, there is an urgent need to identify rice genotypes for enhanced germination even under anoxic stress. Methods: Experiment was conducted in glass house, Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore. In this study, 22 rice germplams with three replications were evaluated for seed and seedling traits underlying anaerobic germination tolerance. Main aim of this study is to explore the starch and sugar relation under anoxic stress and identifying tolerant genotypes for direct seeded rice cultivation. Result: Tolerant genotypes had early emergences, higher shoot and root length along with higher starch degradation and sugar accumulation under waterlogged condition. Cluster analysis revealed that Karuppukavuni, Kalanamak, CBMAS 14065 and Kodavilayan were identified as tolerant genotypes and suitable for wet direct seeded rice cultivation. Finally higher starch degradation coupled with higher accumulation of glucose and fructose were the key traits underlying anaerobic germination tolerance in tolerant genoytpes. Shoot length, root length and sucrose contents had higher genotypic coefficient of variance, phenotypic coefficient of variance coupled with high heritability indicating scope for enhancing anaerobic germination tolerance.