Fig 1.
Representative illustration of the experimental setup deployed in the culture chamber and four incubators for the study of the effect of water stress/or thermal stress on the growth of five durum wheat genotypes: G1: Aouija, G2: Biskri, G3: Hedhba, G4: Karim, G5: Hmira.
Fig 2.
Rate change of six measured variables of five durum wheat genotypes subjected to two levels of drought stress (50% FC and 25% FC), heat stress (30°C and 35°C), and combined stress (50% FC at 30°C and 25% FC at 35°C), evaluated in pots at the juvenile stage (Z14).
Such as A) Aerial part length (APL), B) Dry matter rate (DM), C) H2O2 content (H2O2), D) Phenolic compounds content (Ph.C), E) GPX activity (GPX), F) CAT activity (CAT), *, P<0.05; **, P<0.01; ***, P<0.001; NS: Not significant.
Fig 3.
Graphical representation of the pearson correlations (α = 5%) of the measured parameters of five durum wheat genotypes under drought stress (100% FC, 50% FC, and 25% FC), heat stress (24°C, 30°C and 35°C) and combined stress (100% at 24°C, 50% FC at 30°C and 25% FC at 35°C).
The beige coloring indicates the weakest correlations, and the turquoise coloring indicates the highest correlations. APL: Aerial part length, DM: Dry matter rate, H2O2: H2O2 content, phenolic compounds content (Ph.C), GPX: GPX activity, CAT: CAT activity. *, P<0.05; **, P<0.01; ***, P<0.001; NS: Not significant.
Fig 4.
Principal component Analysis (PCA) of all the measured variables for the five genotypes under three studied stresses: (A) drought stress (100% FC, 50% FC, and 25% FC), (B) heat stress (24, 30, and 35°C), and (C) combined stress (100% FC at 24°C, 50%FC at 30°C, and 25% FC at 35°C). A1, B1, C1: PCA visualization of Individuals per genotype and treatment. Ellipses with 95% confidence were represented to allow clustering among genotypes and treatments. A2, B2, C2: Visualization of the contribution of each variable to the variance of the model with the direction of the variation. APL: Aerial part length, DM: Dry matter rate, H2O2: H2O2 content, Ph.C: phenolic compounds content, GPX: GPX activity, CAT: CAT activity.
Fig 5.
Heatmap representing hierarchical clustering of six measured traits across five durum wheat genotypes based on the significant rate change values in response to drought stress (50% FC, and 25% FC), heat stress (30°C and 35°C), and combined stress (50% FC at 30°C and 25% FC at 35°C) (Euclidean distance measure).
A and B are the clusters based on the genotypes. C, D, E, and F are clusters based on the treatments and the assayed traits. The color bar depicts the gradient of rate change values in response to stress conditions. The different APL: Aerial part length, DM: Dry matter rate, H2O2: H2O2 content, Ph.C: Phenolic compounds content, GPX: GPX activity, CAT: CAT activity.