Agronomic and Morpho-Physiological Characterization of Some Advanced Lines being Selected in Durum Wheat Cultivated in Semi-Arid Conditions

Abstract

Knowledge of agro-physiological traits associated with drought tolerance would be useful for developing breeding materials for drought-prone environments. This study was conducted to estimate genetic variability among nine durum wheat genotypes in response to drought. Our results indicated that the effect of the campaign, genotype, and genotype × interaction was significant for the thirteen variables measured, except for the relative water content. The variability observed was greater for grain yield, biomass, ear fertility, straw and economic yields, chlorophyll content, and cell integrity. Heritability was high for the number of grains per ear and the chlorophyll content; medium for thousand kernel weights, low for grain yield, biomass, and economic yield, and zero for the rest of the variables measured. The results also showed that the agro-morphological characters were significantly linked to each other, unlike the physiological characters which showed non-significant relation between them and with the agro-morphological characters. This suggests that among the varieties evaluated, the selection of those which are tolerant and with high yield potential should therefore be made on a case-by-case basis and not based on a specific physiological character, a marker of tolerance, highly correlated with yield grain. The nine varieties evaluated were subdivided into three divergent clusters of three varieties each. Cluster C1 consists of the least performing varieties, unlike the other two clusters which bring appreciable gains for several characteristics including grain yield, biomass, the weight of 1000 grains, straw yield, and ear fertility and a marked improvement in chlorophyll content and a significant reduction in damage to the cell membrane by thermal stress. In conclusion and following their divergence, it is suggested to use the varieties of clusters C2 and C3 in crossing with the varieties of cluster C1 to improve and reconcile stress tolerance and yield potential in the same genetic background.