In Mediterranean regions, especially around the arid and semi-arid areas, drought is a major abiotic factor that reduces yields in wheat. Identification of reliable criteria in screening for drought tolerance in wheat represents a significant challenge to plant breeders. This study was carried out at two locations (Béni Fouda and Ain Abessa) in Sétif, Algeria. The objectives were to study the performance of durum wheat genotypes (Triticum durum Desf.) in relation to yield and some agronomical traits and the evaluation of carbon isotope discrimination (Δ13C) as a selection criterion for drought tolerance. Analysis of variance revealed that grain yield and all measured parameters (excepted for number of spikes per m2 and thousand kernels weight) were significant (P < 0.01) affected under locations. Among genotypes, significant differences (P < 0.01) were observed for all traits, excepted for biomass. Under both locations (Béni Fouda and Ain Abessa) gain yield was positively and significantly correlated with earliness, number of spikes per m2, number of grain per m2, harvest index and Δ13C. The results suggested that the selection of early heading genotypes would give high grain yield under rain-fed conditions. Also, grain yield could be effectively increased by maximum genetic expression of number of spikes per m2, number of grains per m2 and harvest index. Strong correlations between grain yield and carbon isotope discrimination indicate that Δ13C can be used as indirect criterion in screening for drought tolerance in semi-arid conditions.

This work was carried out at the Field Crop Institute-Agricultural Experimental Station of Setif (Algeria) during the 2008/2009 cropping season. The objective was to evaluate some pheno-morpho-physiological and agronomic traits in five durum wheat (Triticum durum Desf.) varieties and F2 segregating lines. The results indicate the presence of a good amount of variability for the measured traits. Low relationships between wheat productivity and the physiological traits is found, which makes them less effective as selection criteria in the case of this study. However, the above-ground biomass measured at maturity stage seems to be the determinant factor in grain yield expression. High heritability associated with high coefficients of phenotypic and genotypic variation values, along with high genetic gain are recorded for the above-ground biomass and spikes weight per plant, suggesting that early selection based on these traits would be effective to improve the stress tolerance and enhance the productivity of the F2 studied populations.