Anna Tomczyk

Biochemical reaction of Tilia leaves on infestation by some species of gall-inducing eriophyoid mites

ABSTRACT Chemical analysis of healthy leaves of Tilia cordata Mill., T. platyphyllos L. and T. tomentosa Moench and leaves infested by eriophyoid mites was carried out to compare the nutrient values of the Tilia species for Eriophyes exilis (Nalepa), E. nervalis (Nalepa) and Phytoptus tetratrichus Nalepa. Concentrations of sugars, proteins and phenols in leaves were assessed, along with the ratio between the selected primary and secondary metabolites in lime trees grown in the Botanical Garden of the University of Warsaw. No significant difference in the mean ratio of infested-to-healthy leaf area was observed between the two lime tree species (T. platyphyllos and T. tomentosa infested by E. nervalis and E. exilis, and T. cordata infested by Phytoptus tetratrichus). Eriophyoid mite feeding on leaves of Tilia cordata and T. platyphyllos caused a significant fall in the concentration of soluble sugars. In infested leaves of T. tomentosa, the content of soluble sugars remained at the same level, while, contrary to the other two lime tree species, the content of proteins decreased. The concentration of phenols differed significantly in the leaves of the tested lime tree species: the highest concentration was observed in the leaves of T. tomentosa while the lowest in the leaves of T. platyphyllos. T. platyphyllos had the highest nutritional value for eriophyoid mites whose leaves had a high nutrient content but low phenol: sugar and phenol: protein ratios. Among the studied lime tree species, T. cordata’s leaves created the worst conditions for galling species of eriophyoid mites because they had the lowest content of nutrients (proteins and sugars). Additionally, their phenol:sugar and phenol:protein content ratios were higher than those of T. tomentosa and T. platyphyllos.