Rice tolerance variation to long-term stagnant flooding and germination ability under an-aerobic environment

Abstract

Erratic and unpredicted weather due to climate change cause flood in agriculture production area especially when it has poor drainage system. Flood during early season of crop establishment will induce anaerobic germination (AG) in the area where farmers practiced a direct seeding method, and the flood can be prolonged as a stagnant flooding (SF) stress if the water could not recede. AG and SF stress not only will affect the crop establishment but also reduce grain yield. The study on selection of tolerant lines to AG and SF based on phenotypic performance was conducted. We identified a total of 22 rice lines had ability to germinate under low oxygen after initial screening under 10 cm of flooding for 2 weeks. The survival rate was 82.5-100% with seedling growth rate about 0.9-1.5 cm per day. Eight lines had better performance and out yield the best check of SF. SF was increased the plant height, but reduce the panicle length and unfilled grain per panicle. Aerenchyma areas of tolerant variety were bigger than a sensitive variety. The results of study will increase the chance to developing of flood tolerant rice varieties to anticipate the climate change.