Abstract

Rice (Oryza sativa L.) is the primary food crop for more than half of the global population and is cultivated extensively under diverse agro ecological conditions. In eastern India, particularly in Odisha, frequent and unpredictable flooding events during the early stages of crop establishment severely constrain direct seeded rice (DSR) cultivation. Germination under low oxygen (hypoxic) or fully submerged (anoxic) conditions is a critical adaptive trait for ensuring crop survival and yield stability in such ecosystems. The present study evaluated 10 rice genotypes, including traditional landraces, released varieties, and basmati types, for their ability to germinate and establish seedlings under hypoxic conditions. Screening was performed using a 10 cm water column in test tubes and earthen pots. Among all genotypes tested, only ten exhibited more than 50% germination under submerged conditions. Notably, the landraces Parbatjeera and Kalikati recorded over 70% germination and vigorous coleoptile elongation, indicating strong anaerobic germination (AG) tolerance. These genotypes demonstrated the ability to extend coleoptile growth beyond 1 cm, allowing rapid emergence through the water surface and early establishment. The findings reveal considerable genetic variation in AG tolerance among traditional landraces from the Jeypore tract of Odisha, a region known as a secondary center of rice diversity. The identified tolerant genotypes represent valuable genetic resources for breeding rice cultivars resilient to flooding during germination and early seedling stages, thereby supporting climate resilient and sustainable DSR production systems.