Growth and Physiological Responses of Common Yew Seedling to Drought Stress

Common yew (Taxus baccata L.) is one of the 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 useful.

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 growth and physiological traits of common yew seedlings was carried out in a completely randomized design with three replications for 6 months.

The results showed that survival, shoot growth and root diameter growth of seedlings did not change under water deficit, but a significant negative effect in most of the physiological variables (except for stomatal conductance) was found under the 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%.

It can be concluded that the growth traits of yew seedlings were not affected by water scarcity in the first year of growing season, due to the slow-growth nature. Since, common yew seedlings need several years of care in the nursery to prepare for the transfer to the natural field, it is recommended to manage the seedlings in well-watered conditions for a better response of physiological traits and more favorable growth in the coming growing years.