ABSTRACT
Submergence/Flooding is considered to be the most dangerous natural calamity, as well as leading stress constraints on rice cultivation around the world, resulting in significant economic losses. Rain-fed lowland areas prone to seasonal flooding accounted for around 40 million hectares of rice crops globally. Over the last two decades, significant progress has occurred regarding adaptation and tolerance mechanisms in rice towards submergence. The present chapter provides deep insight into flooding stress types, flood water and its environmental characteristics, submergence effect on rice and its morphological, physiological, biochemical and molecular functions in responses to submergence. A brief explanation of rice tolerance mechanisms for various kinds of submergence will be targeted for future crop improvement programmes aimed at developing submergence tolerant rice varieties.
