Abstract
The identification of soil properties and phytochemical compounds including the amino acid profile is at the base of this study, which investigates the adaptive behavior of three legumes plants Acacia tortilis (Forssk.), Alhagi graecorum Boiss. and Retama raetam (Forsk.) collected from Wadi Sudr, South-West Sinai, Egypt. The ANOVA displayed that most mechanical and chemical properties of the soil associated with the three plant species were significantly affected by plants and depths and their interaction (p<0.01). Also, water content was significantly affected by plants, seasons, depths and their interaction (p<0.01). As for plant analysis, the plants, seasons and their interaction was significant (p<0.05 or p<0.01) for most amino acid profiles, photosynthetic pigment contents and chemical compositions of three legumes species in Wadi Sudr region. The amount of most chemical properties was higher in the soil associated with R. raetam compared to the soil of the other plants. Most amino acids, photosynthetic pigments, Na+, K+ and SO42- concentrations of the three studied plants in the dry season were higher than in the wet season. According to PCA, the PCA1 and PCA2 extracted had eigenvalue >1 and mainly distinguished the soil and plant variables in different groups across the three studied plants. According to biplot and based on the plants studied, PCA1 and PCA2 with the highest variability showed positive or negative correlation to soil and plant variables, but, they differed in their degree of significance/insignificance and consistency in quantity. The PCA revealed high positive correlations among some soil variables as well as among some amino acid profile and other plant variables under the plants studied. Some soil variables were positively correlated with some amino acids such as leucine, phenylalanine, valine, lysine, aspartic, arginine, serine and isoleucine as well as some photosynthetic pigments and other plant chemical concentrations.