Genetic potentiality of lowland indigenous indica rice (Oryza sativa L.) landraces to anaerobic germination potential

Poor germination and delayed seedling establishment under flooded soil are the major challenges for the wide adaptation of direct-seeded rice production in both rainfed and irrigated areas. So, in the present study 88 lowland indigenous rice landraces from Koraput, India were evaluated for their anaerobic germination (AG) potential and early seedling vigor traits under flooded soil for two consecutive years. Variations of seed characteristics such as grain size, weight and sugar content along with anaerobic germination as well as early seedling growth parameters were compared with tolerant and susceptible check variety. The morpho-physiological parameters were subjected to principal component analysis (PCA) and cluster analysis. The first five axes of the PCA showed 86.64% of the total variation and indicated large variations among the landraces. Major traits, such as shoot length, root length, fresh weight, dry weight and anaerobic vigor index appeared to be important determinants of phenotypic diversity among the landraces. Three rice landraces (Bausaganthi, Patadhan and Basantichudi) showed superior AG potential compared to check genotypes. In addition, these landraces with higher activity of alcohol dehydrogenase with lower activity of amylase may help them for better seedling establishment underwater. The presence of AG associated primer either RM 3475 or RM 478, with PIC value 0.80 and 0.75, respectively was observed and thus, helpful in evaluating the genetic diversity of studied rice landraces for AG potential. These three landraces showed promising genetic potentiality for AG and could be useful in rice breeding programs.