The Leaf Properties, Stomatal Index and Chlorophyll Content of Turkish Hazelnut (Corylus avellana L.) Cultivars

This study examined the leaf micromorphological properties, stomatal indexes, and chlorophyll contents of 20 Turkish hazelnuts (Corylus avellana) cultivars. The cultivars examined included the "Aci, Allahverdi, Cavcava, cakildak, Fosa, Giresun melezi, Incekara, Kalinkara, Kan, Karafindik, Kargalak, Kus, Mincane, Okay 28, Palaz, Sivri, Uzunmusa, Tombul, Yassi Badem, and Yuvarlak Badem". The chlorophyll content was measured by a portable chlorophyll meter and the surface sections of leaves were excised by hand and all measurements were obtained by using imaging software (NIS - Elements, Version 3.00 SP5). The stomatal index per unit area (1x104 mu m2) was calculated. For scanning electron microscope (SEM) imaging, the dried leaves were mounted on stubs using double -sided adhesive tape. The leaf samples were coated with 12.5-15.0 nm of gold and the coated leaves were photographed using a Hitachi SU 1510 SEM. Three wax ornamentation types were found in the leaf samples (e.g., crust, smooth, and granules). The epidermal features, stomatal index, and chlorophyll quantities showed some differences among the C. avellana cultivars. The importance of stoma width and stoma length were determined for the "Palaz", "Kus", "Yuvarlak Badem", and "Yassi Badem". The stomatal index and width and length of upper epidermis and lower epidermis were identified as distinctive properties for the "Allahverdi", "Kargalak", "Kara", and "Mincane". The chlorophyll density was identified as a distinctive feature of the "Sivri", "cakildak", "Incekara", and "Aci" cultivars. The highest correlation was found at a rate of 0.98 between "Okay 28" and "Tombul" while the lowest correlation was found at a rate of 0.87 between "Sivri - Karafindik", "Sivri -Fosa", and "Sivri - Kargalak".