Résumé:
Wheat landraces sourced from Algerian Saharan oases constitute valuable genetic resources for breeding resilient genotypes in response to environmental stress and climate variability. This study aimed to assess the phenological, morpho-physiological, and agronomic characteristics of 10 Saharan oasis landraces. Furthermore, salt tolerance was evaluated using the membership function value for salt tolerance (MFVS) at 150 mM NaCl, incorporating physiological, agronomic, and biochemical markers. The selected landraces were subsequently integrated into a Line × Tester mating design with other wheat varieties, with the landraces designated as testers and the varieties designated as lines. The first experiment revealed substantial phenotypic diversity among the Saharan oasis wheat landraces, encompassing traits related to productivity, adaptation, and phenology. This diverse array of characteristics underscores the potential of these landraces as valuable genetic resources for breeding programs focused on creating segregating progenies with enriched
genetic diversity and enhanced agronomic traits. The results of the second study identified Oum Rokba Elhamra, Khellouf, and Zeghlou landraces as the most tolerant, while Bourione was classified as the most sensitive one. The salt-tolerant and moderately tolerant wheat landraces maintained stable yields under saline stress conditions. Regression models revealed that for bread wheat, AA and GY accounted for most of the variation in MFVS, whereas for durum wheat, Gr. plant-1 and Na+ explained the majority of the observed differences. The results of Line × Tester analysis revealed existence F1 hybrids crosses have tapped into a wider range of genetic diversity. Data demonstrated that HB10 and HD6 expressed the highest number of favorable heterosis. The analysis revealed that non-additive genetic effects played a dominant role in determining the inheritance patterns of all studied traits except in FLA and SL in bread wheat and FLA, PH, AL, HT, ST, and HD in durum wheat. Correlation analysis revealed that GCA values of parental lines and testers HYB can be more effectively predicted based on GCA of parental lines in almost al traits. Evaluating the effect of salinity of F2 hybrids and their parents’ performance and genetic parameters revealed that all the studied traits were governed by non-additive genes under control and stress conditions except Pro in durum wheat. Desirable heterotic effects for slat-related traits was registered in the two species where some appeared to be consistent under bother conditions. In bread wheat, most 71% and 56% of hybrids with significant SCA were obtained from parents with different GCA status (poor × good or good × bad) under control and salinity conditions, respectively. For durum wheat, 65% were obtained from parents with different GCA status under control, while upon exposure to stress 75% of were derived from good × good combiners or poor × poor combiners.
