Water use, water use efficiency, water soluble carbohydrate and yield of four varieties of wheat in continuously high temperatures

Abstract

High temperatures are a common feature of the environment of tropical regions such as Lombok Island and although the effect can be alleviated by altitude, heat stress will be an important limitation to the productivity of wheat in this environment. The objectives of the experiment were to observe the responses of water use (WU), water use efficiency (WUE) and water soluble carbohydrate (WSC) to high temperatures on growth and yield of wheat under controlled conditions. In this experiment plants were grown under growth chambers at temperatures to simulate low and high elevation locations on Lombok Island. Water use, water use efficiency, WSC and yield of 4 wheat genotypes (2 Australian and 2 Indonesian varieties) grown at 3 temperatures (32°/23°C, 28°/20ºC, and 25°/15ºC day/night) were compared. Variation in water use, water use efficiency, and the concentration of water soluble carbohydrate was found. Indonesian wheat varieties, Nias and Dewata produced higher yield and biomass and maintaining higher rates of water use and remobilisation of water soluble carbohydrate from vegetative tissues to grain. The accumulation of water soluble carbohydrates was an important adaptive characteristic that was strongly associated with grain weight and grains per spikelet and maintained better yield.