Designing and validation of a rapid and reliable protocol for screening anaerobic germination tolerance in rice

Anaerobic germination is one of the important traits for direct seeded rice cultivation. Identification of tolerant rice genotypes is needed for improving early vigour under anaerobic germination. This study was aimed to identify a rapid and reliable protocol to identify the tolerant rice genotypes for anaerobic germination. Four screening methods viz., protrays, plastic trays, plastic tumbler and mud tumbler methods were developed and 22 rice genotypes were subjected to anoxic stress. Mud tumbler method was identified as the best screening protocol. Mud tumblers are eco friendly and also mimic the pot culture experiments. Principal component and cluster analysis revealed, Karuppukavuni and Kalanamak as tolerant genotypes. They recorded higher coloeptile traits and showed enhanced germination under early flooding. TKM13 and Anna R4 were identified as moderately tolerant genotypes under anaerobic germination. Higher genotypic coefficient of variance, phenotypic coefficient of variance coupled with high heritability was noticed in shoot length, crude protein and proline indicating scope for enhancing anaerobic germination tolerance.