The Early Stages of Grain Development in Wheat: Response to Water Stress in a Single Variety

Abstract

In wheat (Triticum ae8tivum cv. Gabo) a temporary water deficit in the first 7 days following anthesis significantly reduced the final grain weight per ear. A reduction in seed set in response to stress was associated with an initially greater rate of development of the remaining grains, with an enhanced rate of cell division in the endosperm. Relative turgidity measurements indicated that the stress applied did not significantly reduce grain water content, although the ear structure showed some water loss, and the stem and flag leaf blade were quite severely stressed. Th!' greater desiccation of the leaf and stem in comparison with the ear was reflected in the lower rate of photosynthesis of these organs under stress conditions.