Effects of seed preconditioning treatments on PSB RC82 (Peñaranda) rice under varying submergence levels

Abstract

Rice production in lowland farms such as Nueva Ecija and Tarlac is threatened by increasing incidence of flash floods and submergence associated with climate change. As a solution, the submergence-tolerant Rc82 rice was developed by the Philippine Rice Research Institute. This study evaluates the effect of seed priming on the morphology and physiology of Rc82 rice seedlings grown in soils with 100%, 120%, and 140% water holding capacity. Results showed that priming significantly increases root length and root-to-shoot dry weight ratio while it decreases shoot length of Rc82 rice when grown in flooded conditions. Physiologically, seedlings from primed seeds of Rc82 rice demonstrate significantly higher non-structural carbohydrate content with no effect on chlorophyll and relative water content under submerged conditions. These responses will enhance the chance of survival of Rc82 rice seedlings in flooded conditions, making priming a promising way to grow submergence-tolerant rice seedlings during rainy seasons.