Water stress tolerance and proline accumulation in Phaseolus vulgaris L.

The water stress tolerance of five agronomic varieties of Phaseolus vulgaris of different geographical origin in Tanzania was studied. As indicators of water stress tolerance water saturation deficit (WSD), stomatal resistance, and flower and pod abscission were used. Of three of these varieties also proline accumulation under stress conditions was determined. In both respects the varieties showed significant differences. Between water stress tolerance and proline accumulation under stress conditions a positive correlation was found. The possibility to use proline accumulation as an indicator in selection schemes for water stress tolerance in Phaseolus vulgaris is discussed.