The comparative analysis of anatomical traits of four largefruited hazelnut cultivars showing different susceptibility to filbert aphid (Myzocallis coryli Goetze) feeding

Investigations related to morphological and anatomical traits of leaves of four largefruited hazelnut (Corylus L.) cultivars characterised by different susceptibility to filbert aphid (Myzocallis coryli Goetze) feeding. The following parameters were measured: the thickness of leaf blade, the number of stomata, the length of secretory and mechanical hairs and their density on the leaf, the thickness of adaxial and abaxial epidermis and the thickness of their external cell walls. Observations of cross sections of the leaves were made in a light microscope and the surface of the adaxial epidermis was analysed in a scanning electron microscope. It was shown that leaves of the cultivars susceptible to M. coryli feeding had the thinnest leaf blade, especially in the main vein, and many more stomata. Besides, the cultivar most resistant to filbert aphid feeding, White Filbert, was marked by the largest height of the adaxial epidermis cells and the strongest striation of the cuticle in abaxial epidermis. On leaves of this cultivar, the number of mechanical hairs was the highest, while the lowest number of them was noted on Wonder from Bollwiller, the most susceptible cultivar