Interactions génotype-milieu de variétés de blé tendre (Triticum aestivum L.) sous stress hydrique

Abstract

Knowledge of the physiological, biochemical, agronomic and technological traits involved in plant adaptation process to abiotic stresses is a decisive step in the fight against drought. This study is a contribution to understanding the mechanisms of tolerance to water stress in bread wheat varieties Triticum aestivum L. and to establish genotype-environment interactions to evaluate the genotypic variability. In the first series of tests, the study shows that the varieties introduced Cham 6 Hamam 1 and Attila are the most productive. The local variety Ain Abid followed by Attila of Angi-4 are the most tolerant to water stress. The second experimental trial is to test during two campaigns, 10 bread wheat lines at three different geo-climatic sites: Setif, Constantine and Guelma. The results of phenological, morphological and agronomic parameters fluctuate over time and space. The earliest species provide lower performance parameters to Guelma, while the later varieties give the best yields in Constantine. Local varieties Ain Abid, Arz and introduced line Prl / 2 * Pastor provide the best yield and its components on Setif sites. This last line with Pastor / Wbll1 and Hidhab feature a performance by high yield and components of yield on Constantine and Guelma. The interaction genotype-environment is very highly significant between all studied agronomic parameters. On the site of Setif (semi-arid) are rated the highest levels of total protein for Thelin line // 2 * Attila * 2 / Pastor, while Prl / 2 * Pastor accumulates the most important starch contents on Constantine site. Total protein levels are higher on experimental testing of Setif, while higher levels of starch and moisture are obtained for all varieties grown on Constantine and Guelma. The genotype-environment interaction is highly significant for all biochemical and technological parameters. The data show that the line Kauz / Pastor / Fiscal has the highest values W (dough strength) to G (swelling of dough), it also gives the best Pelshenke compared to other lines, it is followed by Pastor / Wbll1 and Thelin // 2 * Attila * 2 / Pastor lines. The latter are characterized by a very high baking strength (strength of wheat). It's on the sites of Setif and Guelma that are expressed wheat lines with the most efficient technological parameters. The wide variability in gluten strength, character controlled mainly by the allelic variation of loci Glu-A1; Glu-B1; Glu-D1, gives an idea about the genetic diversity obtained by expression and composition of these loci. Gluten, rheological parameters alveograph (W, P), Pelshenke test and SDS sedimentation volume vary as a function of the allelic diversity HMW glutenins. The results show the superiority of the alleles 22, (6 + 8), (7 + 9), (2 + 12), (10 + 5) and (7 + 8), compared to other alleles controlling these parameters.