Growth and sugar accumulation in durum wheat plants under water stress.

The effect of water stress on growth of Trillium durum L. was investigated in relation to sugar accumulation and water status of wheat plants before, during and after a period of water stress. The slight decrease in water potential in the first few days after withholding water had no detectable effect on growth. Inhibition of growth was only apparent when the water content started to decline. Dry weight continued to increase during water stress, even under severe stress (after day 27) which was associated with n sharp rise in sugar content, accounting for 20% of the gain in dry matter between days 27 and 31. The increase in leaf length and leaf area of stressed plants fallowing re-watering, from day 31, was owing to the leaves regaining turbidity after witting. Growth inhibition coincided with a considerable increase in sugar content. The role of growth inhibition and other factors in sugar accumulation under water stress is discussed, Photosynthesis rather than reserve starch might be the major source of sugar accumulated under water stress in durum wheat.