Investigation of anatomical changes induced in Fraxinus rotundifolia leaflets by Psyllopsis (Psyllopsis fraxini) infection

Pest attack is able to damage plant cell structures and also affects the growth and plant differentiation. The Psyllopsis is one of the plant-attacking pests which feeds on plant sap and causes the leaf morphological deformation and induces the formation of galls. The aim of this study is investigation of the anatomical and morphological changes produced in leaflets of pest-infected plants (Fraxinus rotundifolia) in different stages of pest infection. The light and fluorescent microscopic analysis was carried out from infected and non-infected leaflets and staining was performed by using eosin-hematoxylin, safranin fast green, black sudan and comasi berliante blue. The results showed that upon the attack of the pest, its saliva entered in the infected site and induced chlorosis. In addition, the galls were formed in both lower and upper sides of the leaves, and hypertrophy and hyperplasia were observed in palisade and spongy cells as well as hypertrophy in vascular bundles of the leaves. Moreover, reduction in intercellular space in the peripheral Psyllopsis feeding area of parenchymal cells and increase in cell wall thickness of parenchymal and epidermal cells were observed. All of these changes can be considered as a suitable ecological niche for Psyllopsis establishment.