A Review: Elevated Nighttime Temperature Impacts on Rice
Dipak Khanal *
Department of Soil and Crop Sciences, Texas A&M University, College Station, Texas 77843, USA.
Babita Bastakoti
Institute of Agriculture and Animal Science, Lamjung Campus, Tribhuvan University, Nepal.
Dhurba Banjade
Institute of Agriculture and Animal Science, Gauradaha Campus, Tribhuvan University, Nepal.
*Author to whom correspondence should be addressed.
Abstract
High nighttime temperatures adversely affect rice grain yield and quality by causing early panicle emergence, decreased pollen germination, increased spikelet sterility, and chalkiness. The severity of these effects depends on genotype, growth stage, stress period, and temperature. High nighttime temperature leads to structural abnormalities in starch granules, modify the amounts of amylose and amylopectin, and disturb the expression pattern of genes involved in starch biosynthesis and accumulation, ultimately affecting the cooking properties of rice grains. To ensure sustainable rice production in the context of global warming, rice breeding efforts must consider yield attributes focusing on the interactions between heat stress, genetic variables, and grain quality. This article provides an overview of current research on the significant impacts of high nighttime temperatures on rice grain production, starch granularity, physiochemical characteristics, and cooking properties.
Keywords: Chalkiness, high nighttime temperature, rice grain, starch granules