Determination and distribution of cyst nematodes (Heterodera spp.) in kale (Brassica oleracea var. Acephala) production areas in eastern Black Sea Region of Türkiye

This study was carried out in 2021-2022 in order to detect cyst nematodes (Heterodera spp.) in kale (Brassica oleracea var. acephala) production areas of the Eastern Black Sea Region and to their infestation status. For this purpose, 77 samples were collected from 56 districts covering Ordu, Giresun, Trabzon, Rize and Artvin provinces in 2021 and 2022. Soil samples were taken from around the root of the kale plant. Nematodes were obtained using Cobb's sieve method. The nematodes were identified using morphological chracters and molecular analysis. For molecular analysis, the ribosomal DNA region including the gene region of 28S ribosomal RNA (rRNA) (ITS1, 5.8S, ITS2) was amplified using primer sets TW81/AB28 and the D2-D3 expansion segments of 28S ribosomal RNA (rRNA) were amplified using primer sets D2A/D3B. In addition, the Cytochrome Oxidase I (cox1) region of mitochondrial DNA (mtDNA) was used using the species-specific primer set (Car-F/Car-R) for Heterodera carotae. As a result of the analysis, cyst nematodes Heterodera carotae, Heterodera cruciferae and Heterodera fici species were identified in the areas where kale grows in the Eastern Black Sea region. In the study, Giresun province was the first with a 35.29% infestation rate in the areas where kale was produced, followed by Trabzon and Ordu provinces with 21.05% infestation rate, and Rize province with a 13.33%. No cyst nematode was found in the samples taken in Artvin province. In the study, among the species detected, the most common species was H. cruciferae with 76.4%, followed by H. carotae at 17.6%, and H. fici at 5.8%.