STUDY OF DIRECT RESPONSE AND RELATED TO THE EARLY SELECTION OF DURUM WHEAT (TRITICUM DURUM DESF.) GENOTYPES GROWING UNDER SEMI-ARID CONDITIONS

This study which was leaded in agricultural experimental station of technical field crops institute (TFCI), (ITGC in French) of Setif, East Algeria. The objective of this study is to evaluate the direct response and related to two F4 and F5 generations for the early selection of three hybrids viz., Ofanto/MBB, Ofanto/Waha, and Ofanto/Mrb5 of durum wheat (Triticum durum Desf.) growing under semi-arid conditions. Analysis of variance shows the presence of genetic changes for all measured traits in parents. Direct and indirect early selection of crossbreeds of these three advanced generations shows that the same character taken as a selection criterion gives increased effectiveness for some traits in crossing without other. By comparison between the observed increases in grain yield, the highest increases in gain yield were chosen by selection on the basis of grain and economic yield, number of ears and indexes (DSI, SWI). The following up of response of lines with high grain yield indicates (G x E) interaction for most lines. Among these three hybrids, Ofanto/MBB combined most desirable characters (Production, resistance etc.) by lowering of canopy temperature (CT) and increasing of grain yield. Linear regression analysis (R2) shows a highly significant correlation between grain and economic yield (R2>0,900) and the number of spikes (R2>0,670), contrariwise no correlation between productive traits and those of resistance. The results of this study proved that the advanced line Ofanto/MBB has combined more desirable traits (Productivity and resistance, ext.) by lowering of a canopy temperature (CT) and increasing of grain yield.