Evaluation of proline accumulation as an indicator of drought tolerance in spring wheat cultivars
The aim of this study was to evaluate proline accumulation as an indicator of drought stress and drought tolerance in spring wheat cultivars (Triticum aestivum L.) grown in the Western Cape. Drought stress was induced in whole plants and leaf discs in two cultivars with known drought tolerance, namely, Gamtoos (drought tolerant) and SST 66 (slightly drought sensitive), as well as in two cultivars with unknown drought tolerance, namely, Nantes and SST 44. To assess the effect of growth stage on the reaction of the cultivars to drought stress, stress was induced during pre-anthesis and also during anthesis. Proline accumulation in whole plants showed clear genotypical differences during pre-anthesis and, to a lesser extent, during anthesis. A positive correlation between the degree (onset and extent) of proline accumulation and drought tolerance was found for Gamtoos and SST 66. Proline accumulation patterns in leaf discs did not correlate with results obtained with whole plants.