Relationships among adaptation patterns, morphophysiological traits and molecular markers in durum wheat

Breeding for specific or wide adaptation would be more cost-efficient if preliminary indications on genotype adaptive responses could be provided by easily-detectable morphophysiological or molecular characteristics. We investigated the consistency among adaptation parameters, morphophysiological traits and SSR markers in estimating and structuring the genetic diversity among 24 durum wheat genotypes. Additive main effects and multiplicative interaction adaptation parameters were estimated across 14 Algerian locations belonging to a low- or a high-elevation subregion. Eight morphophysiological traits were assessed in two locations per subregion. Genotype Euclidean distances based on adaptation parameters were closely related to those based on morphophysiological traits (r = 0.75, P = 0.01). Marker-based distances exhibited low correlation with those based on adaptation parameters (r = 0.26, P = 0.01) or morphophysiological traits (r = 0.32). The consistency between adaptation parameters and morphophysiological traits for genotype ordination and classification was greater than that between either information layer and SSR markers. Optima of phenology and plant height differed between subregions, whereas many kernels per spike and fertile tillers were associated with adaptation to both subregions.