Callus induction, growth, and metabolite variations in two Taxus spp. under in vitro conditions

The present study investigated the effect of growth regulators on the quantity and quality of calli of two yew genotypes (Taxus spp.). A factorial experiment based on a completely randomized design was performed using 2,4-D and kinetin on leaf and stem explants of T. baccata and T. brevifolia. Calli traits, including fresh weight, total phenols, total alkaloids, and paclitaxel contents were investigated. The simple effect of hormonal treatments on total phenolic content, total alkaloids, and fresh weight of calli was significant. Total phenols content and fresh weight were not much affected by the interaction of hormonal treatments, whereas total alkaloids content was found increased. Paclitaxel content did not significantly differ between explants. The highest paclitaxel content was found in the leaf explant of T. baccata (30 μg/g), compared to 5 and 10 μg/g in T. baccata stem, T. brevifolia stem, and T. brevifolia leaf, respectively. The fresh weight and total alkaloid content of stem calli of both species were higher than the leaves. Yew is a valuable endangered medicinal plant that responds well to in vitro treatments. Therefore, it is possible to manage the production of its valuable metabolites under in vitro conditions.