EFFET DE LA SELECTION DE LA BIOMASSE ET DES EPIS SUR LE RENDEMENT DU BLE DUR (Triticum durum Desf) SOUS CONDITIONS SEMI-ARIDES

Abstract

Traditional selection for yield performance under variable environments made little progress due to the low heritability and genotype x environment interaction of grain yield. Analytical approach suggested the use of correlated traits with yield which confer adaptation to unfavorable environments. The present contribution analyses the effect of indirect selection practiced on F2, on above ground biomass, spikes weight and their combination in an index, and direct selection on grain yield, measured in the F3 generation of three durum wheat (Triticum durum Desf.) populations: Ofanto/MBB, Ofanto/Waha and Ofanto/Mrb5, under semi-arid conditions of the high land of Sétif. The results indicated positive and significant responses for the selected traits, followed by positive correlated responses for grain yield, economical yield (grain + straw) and 1000- kernel weight. The selection effect on grain yield varied according to the population yield potential. No differences were observed among the three criteria within Ofanto/MBB and Ofanto/Waha populations; while in Ofanto/Mrb5 population, selection based on spikes weight showed the best yield gain. Due to the climatic variability of the target region of the high plateaus, it is suggested to apply selection index to cumulate adaptation and yield potential.