Growth and Physiological Responses of Common Yew Seedling to Drought Stress

Aims: The common yew (Taxus baccata L.) is an endangered species in Iran. Considering the prospect of climate change and global warming in the coming years, research on the tolerance of its seedlings to drought stress can be helpful. Materials Methods: This research was conducted on four-year-old common yew potted seedlings. For this purpose, the effect of drought stress (100% and 30% of field capacity (FC)) on the growth and physiological traits of common yew seedlings was carried out in a completely randomized design with three replications for six months. Findings: The results showed that survival, shoot growth, and root diameter growth of seedlings did not change under water deficit, but a significant adverse effect in most of the physiological variables (except for stomatal conductance) was found under stress (30% of FC); so, the activities of photosynthesis, transpiration, mesophyll conductance and water use efficiency decreased by 68.3%, 23.9%, 69.6% and 57.9%, respectively; On the contrary, intercellular CO2 increased by 4%. Conclusion: Due to their slow growth, water scarcity did not affect yew seedlings’ growth traits in the first year of the growing season. Since common yew seedlings need several years of care in the nursery to prepare for the transfer to the natural field, it is recommended that they be managed in well-watered conditions to better respond to physiological traits and more favorable growth in the coming growing years.