Phylogenetic Insights and Race Differentiation in Meloidogyne spp. with Implications for Sustainable Pest Management

Root-knot nematodes ( Meloidogyne spp.) are among the most destructive plant-parasitic nematodes in greenhouse vegetable production systems. Although some studies are available, the occurrence of Meloidogyne species and races in greenhouses in Turkiye is not yet well understood. Therefore, in this study, 80 root samples with typical gall symptoms were collected from infested greenhouses in nine provinces of the Aegean Region of Turkiye (Mugla, Izmir, Aydin, Manisa, Denizli, Balikesir, Usak, Canakkale, and Kutahya) during the 2020–2022 growing seasons. Isolated populations were morphologically identified based on the perineal pattern of adult females and morphometric features of second-stage juveniles. Molecular identification of species was performed using species-specific (Inc-K14F/Inc-K14R, FJav/RJav, Far/Rar) and universal D2a/D3b) primers in PCR assays. Furthermore, race identification was conducted on 48 populations using the North Carolina Differential Host Test. As a result of species and race determinations, Meloidogyne incognita (n = 56; race 2: 16, race 5: 1, race 6: 15), M. javanica (n = 17; race 1: 13, race 5: 1), M. arenaria (n = 2; race 2: 2), and M. hispanica (n = 5) were identified. Notably, M. hispanica was recorded for the first time in Turkiye in this study. The identification of this species represents a new record for the Turkish nematofauna, contributing novel data to the distribution of Meloidogyne species in the region.