Elucidating the genetic potential of rice germplasm for anaerobic germination tolerance in rice (Oryza sativa L.)

Abstract

Rice (Oryza sativa L.) serves as the staple food for over 50% of the global population. Puddled transplanted rice (PTR) remains the most prevalent method of rice cultivation. However, challenges like declining water tables, escalating water scarcity, higher labor costs and elevated methane emissions are diminishing its productivity and profitability. These factors have spurred the quest for an alternative crop establishment approach. Direct-seeded rice (DSR) is gaining traction due to its lower input requirements in comparison to PTR. Although DSR is a profitable and effective alternative method of rice cultivation to PTR, flooding during sowing which hinders seed germination is a major limiting factor in DSR. This study aimed to elucidate the genetic potential of anaerobic germination tolerance (AGT) of 121 rice genotypes which consists of 100 land races, twenty commercial varieties and a pipe line culture. All the genotypes were screened artificially in glass house condition using seedling box cup method. AGT of the genotypes were assessed based on two important morphological traits viz., Anaerobic Germination Percentage (AGP) and Anaerobic Vigour Index (AVI). Five land races with accession numbers RL 79, RL 4088, RL 141, RL 3849 and RL 639 showed more than 90 % AGP under anoxic condition coupled with high AVI values ranging from 2872.9 to 4702.6. These genotypes also recorded high values for Shoot length and it ranged from 23.86 to 43.28 cm. The genotypes viz., RL 79, RL 4088, RL 141, RL 3849 and RL 639 having ability to germinate under anaerobic condition may be used as a potential donor for developing high yielding rice varieties with AGT, which is required for the area expansion of DSR method of rice cultivation in future.

Keywords

• rice
• anaerobic germination tolerance
• genetic diversity