Physiological tests as predictive appreciation for drought tolerance in durum wheat (Triticum durum Desf.)

Abstract

Genetic advances in grain yield under rainfed conditions have been achieved by empirical breeding methods. Progress is slowed, however, by large genotype x season and genotype x location interactions arising from unpredictable rainfall, which is a feature of dry environments. A good understanding of factors limiting and/or regulating yield now provides us with an opportunity to identify and then select for physiological traits that increase drought tolerance and yield under rainfed conditions. Applying different physiological tests to appreciate drought tolerance in seedlings of durum wheat varieties leads to faster selection methods. Five (5) tests (germination, chlorophyll fluorescence extinction, electrolyte leakage, water and osmotic potential) were undertaken to evaluate the level of tolerance to water stress for 190 wheat accessions. Chlorophyll fluorescence extinction measurement seems to be the most reliable test enabling the discrimination of varieties according to their drought tolerance.