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

Abstract

This study examined the leaf micromorphological properties, stomatal indexes, and chlorophyll contents of 20 Turkish hazelnuts (Corylus avellana) cultivars. The cultivars examined included the ‘Acı, Allahverdi, Cavcava, Çakıldak, Foşa, Giresun melezi, Incekara, Kalınkara, Kan, Karafındık, Kargalak, Kuş, Mincane, Okay 28, Palaz, Sivri, Uzunmusa, Tombul, Yassı 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 (1x 104 μm2) 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 Scanning Electron Microscope. 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’, ‘Kuş’, ‘Yuvarlak Badem’, and ‘Yassı 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’, ‘Çakıldak’, ‘Incekara’, and ‘Acı’ 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’-‘Karafındık’, ‘Sivri’-‘Foşa’, and ‘Sivri’-‘Kargalak’.

Keywords

• corylus avellana
• leaf micromorphology
• scanning electron microscopy
• spad
• stoma