Ma

Die Bodenkultur - Journal for Land Management, Food and Environment

R.- K. MA and J.- L. JIAN:

Responses of Seedlings to Water Stress in Different Genotypes of Winter Wheat

Summary

The responses of different genotypes in winter wheat to drought stress were studied with wheat seedlings grown in vermiculite culture in a growth chamber. The stressed plants were kept without water from seedling emergence on, while the control plants were kept under favourable water conditions by weighing and watering to the original level every day. Water loss, leaf water potential, leaf stomatal resistance and transpiration, and root and shoot dry matter were measured. It was found that water stress considerably affected the growth of roots and shoots, due to reduced leaf water potential, increased stomatal resistance, and reduced transpiration. It seems, however, that water use efficiency (WUE) increased somewhat under stress. It was shown by the physiological measurements that the cultivars used responded differently to water supply. HB25 showed both a higher production potential and higher WUE under favourable water supply. In terms of absolute values, but not relative values of biomass, WUE, transpiration rate, leaf water potential and stomatal resistance, RB25 is superior to the native Yulinbai, an assumed drought-tolerant variety. Therefore, it is suggested that a re-appraisal of the so-called 'drought tolerant' varieties, especially local ones, would be worthwhile.