Effect of Temperature on Grain Growth and Protein Accumulation in Cultured Wheat Ears

Abstract

The growth of the grain and the non-grain parts of wheat ears grown in culture was more rapid at 25°C than at 21 or 15°C. The non-grain portion of the ear accounted for 40% of ear growth at 25°C over a 21-day period of culture while at 15°C it was 23%. The rate of grain growth was, however, higher at the higher temperature. Ear growth per unit weight of dry matter taken up from the culture medium was higher at 25°C than at lower temperatures. More soluble sugar accumulated in the bracts at high temperature but there was no corresponding increase in grain sugar. High temperature did not lead to increased grain nitrogen levels as has been observed for whole plants. The proportion of total ear nitrogen translocated to the grain was higher at 15 and 21°C than at 25°C.