Response of Diverse Rice (Oryza sativa L.) Varieties to High Night Temperature and Ethylene Perception Inhibitor.

The impact of climatic change on crop production is a major global concern. One of the climatic factors, night temperature (NT), which is increasing as a part of global warming, can alter crop productivity and quality. The ethylene perception inhibitor, 1-methyl cyclopropene (1-MCP) can minimize high night temperature (HNT) stress-induced damage to the membranes, thereby preventing loss in the rice yield. A study was conducted to evaluate the effects of HNT and 1-MCP on rice physiology, yield-related parameters and yield of nine diverse rice varieties. Plants were subjected to free-air temperature enrichment within a greenhouse (Texas A&M AgriLife Research Center in Beaumont, Texas, U.S.A.) and were exposed to 25 ^oC and 30 ^oC NT from boot stage until harvest. The 1-MCP was applied at boot stage of the rice plant. Leaf photosynthetic rate, photochemistry, membrane stability, chlorophyll concentration, pollen viability, spikelet fertility and grain yield were determined. Differential responses among the varieties to HNT and 1-MCP were seen with respect to physiology, yield-related parameters and yield. These data should help unravel the physiological differences between varieties showing susceptible versus tolerant responses to high night temperatures.