Characterization of Old And Recent Durum Wheat [Triticum turgidum (L.) Tell. convar. Durum (Desf.) Mackey] Varieties Assessed under South Mediterranean Conditions

This work reports on the characterization of 58 old and modern durum wheat grown under south Mediterranean conditions. The experiment was conducted in a randomized complete block design at two locations (ITGC-AES of Setif and Khroub, Algeria) and during the 2015/16 and 2016/17 cropping seasons. The results indicated that, averaged across seasons and locations, modern varieties outperformed the old ones in terms of grain yield, spike number, spike weight, number of kernels per square meter, harvest index, spike fertility and stay green. Old varieties outperformed the modern ones in terms of straw yield, lateness, tallness and flag leaf area. Modern varieties were stress tolerant and more responsive to improved growth conditions, showing agronomic stability type. Old varieties were characterized by a minimal responsiveness to improved environmental conditions, stress tolerance, and biological stability type. Pearson’s correlation coefficients and path analyses indicated that, in both sources of germoplasm, the strong influence of biomass, spike number, spike fertility and harvest index on grain yield. Physiological traits had negligible direct effects and small indirect effects via biomass, spike number and harvest index. Principal component analysis revealed that the old varieties are genetically far from the improved ones suggesting that old varieties represent an important gene pool for important traits among which plant height and straw yield. Differences between both sources of germoplasm are suggested to be used usefully in breeding to enhance yield potential, stability and resilience to changing climate of the future varieties.