Etude de la variabilité et du contrôle génétique de la réponse aux stress hydrique et thermique du blé dur (Triticum durum DESF) : application des tests de la stabilité membranaire et de la rétention de l’eau des feuilles excisées.

Abstract

The aim of this work is to study the variability and genetic control of the drought and thermal stress response of durum wheat (Triticum durum Desf.). The experiment was conducted at Technical Institute of Field Crops (ITGC) Station of Setif during three campaigns 2016/2017, 2017/2018 and 2018/2019. Sufficient variability was observed for most characters. The result indicates that the majority of the variation observed is mainly environmental rather than genotypic. Analysis of GxE interaction indicates that this interaction influences the expression of most variables. Based on stress indices, either widely or specifically, adapted lines were identified. Path analysis pointed out to above ground biomass, harvest index, spike fertility and spike number as yield determinants, suggesting that these traits are of interest in the breeding program. The results of the correlation show that the selection of yield and stress tolerance is difficult via physiological and morphological traits as to the absence of correlation between these characters. Complexes crosses, between parents carefully chosen for these specific characteristics, are necessary to enhance favorable genetic linkage and to generate new basic segregating populations with high genetic variability for these traits.