Genotype-dependent In Vitro Propagation Responses of Newly Registered Turkish Hazelnut Cultivars

Abstract

Hazelnut (Corylus avellana L.) genetic resources are essential for biodiversity conservation and breeding programs. Recently registered cultivars with valuable agronomic traits require efficient clonal propagation systems to ensure the production of disease-free planting material and the establishment of uniform orchards. Although micropropagation offers a promising alternative to conventional propagation methods, hazelnut remains a recalcitrant species due to low regeneration capacity and frequent latent contamination. In this study, four newly registered Turkish hazelnut cultivars (Okay 28, Allahverdi, Çetiner, and Süslü) were evaluated for their in vitro propagation responses. Axillary nodal explants collected between May and August 2025 were surface-sterilized and cultured on Nas and Read Medium (NRM) supplemented with 5 mg L-1 BA and 0.01 mg L-1 IBA. After four weeks, contamination and shoot induction rates were recorded. The highest contamination levels were observed in ‘Okay 28’ (84%) and ‘Çetiner’ (85%), whereas ‘Süslü’ (23%) and ‘Allahverdi’ (39%) showed the lowest contamination. Correspondingly, ‘Süslü’ and ‘Allahverdi’ exhibited the highest shoot induction rates (56% and 44%, respectively). During multiplication, ‘Süslü’ produced the highest number of shoots per explant (2.3) and the greatest shoot length (4.6 cm). Rooting on NRM supplemented with 2 mg L-1 IBA revealed significant genotype-dependent variation. This study represents the first report on the in vitro propagation of these newly registered hazelnut cultivars and highlights the importance of genotype-specific optimization for efficient micropropagation and germplasm conservation.

Keywords

• Corylus avellana
• hazelnut
• micropropagation

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