Effect of substrate on germination, growth, and anthocyanin pigment accumulation in

Optimizing growing conditions is essential for the conservation and promotion of medicinal plant species such as Caralluma tuberculata, a succulent plant of great medicinal importance. This project, this particular research was done at the experimental station of the Faculty of Sciences in Oujda, aims to evaluate the impact of two types of substrates, peat and sand, on the morpho-physiological parameters and anthocyanin pigment accumulation in Caralluma tuberculata. The study compared the effect of these substrates on germination rate and kinetics, as well as aerial and root development and red pigment concentration in transplanted seedlings. The results show that the final germination rate is not significantly different between the two substrates (p=0.358), although peat promotes faster kinetics. On the other hand, peat proved to be significantly superior for growth, resulting in significantly greater stem height (8.49 cm) and root length (8.26 cm). Conversely, sand caused an extremely significant accumulation of anthocyanin pigments, reaching 100.00%, compared to 16.20% for peat. This accumulation is interpreted as a physiological defense response to the more pronounced environmental stress in the sandy substrate. These results suggest that the choice of substrate should be based on the cultivation objective. For biomass production, peat and sand should be used to induce protective secondary metabolites.