Loranthus europaeus Jacq. infection alters leaves morphology and physiology of Persian oak (Quercus brantii Lindl.)

Abstract

Leafy mistletoes are semi-parasitic plants that have negative impacts on their hosts, but there is inadequate knowledge about the impacts of Loranthus europaeus Jacq. on Persian oak trees (Quercus brantii Lindl.). This study examined the impacts of L. europaeus Jacq. on morphological and physiological characteristics of Persian oak tree leaves in western Iran. A forested area infested with L. europaeus Jacq. was selected to study. Five infected and five healthy Persian oak trees were selected. Leaf samples were collected from the southern side of infected and healthy tree crowns to quantify and compare the leaf area, leaf weight, and concentrations of leaf minerals. The area and weight of leaves and the amount of leaf K, P, and Ca in healthy trees were statistically more than in infected trees. Leaf N, Mg, Mn, Zn, and Fe contents were not significantly different between healthy and infected trees. The higher amount of leaf area and weight in healthy trees suggested that they had a better growing status, which increased their leaf size and weight. The higher concentrations of K and P in healthy trees indicated their greater growth and resistance to stresses such as mistletoe. Thus, mistletoe causes physiological disorders and decreased growth in oak trees.