Incidence and diversity of plant-parasitic nematodes associated with wheat-cropping systems in the inner part of the Aegean Region of Turkey

Summary Plant-parasitic nematodes are among the most influential soil organisms worldwide and have a detrimental impact on wheat productivity; they also play a major role in maintaining soil diversity. However, limited information is available on the biodiversity of nematodes associated with wheat cropping systems in Turkey. To address this knowledge gap, 45 wheat fields in the Afyonkarahisar Province of Turkey were sampled in 2021 in order to extract and identify nematodes. A total of 14 genera and 44 species of these nematodes were identified based on their physical traits and ITS DNA sequences examination. Shannon diversity index was used to determine the prevalence and biodiversity features of these nematodes. This study represents the first comprehensive research on plant-parasitic nematodes from wheat-growing regions in the Afyonkarahisar Province. The genera Helicotylenchus, Heterodera, Merlinius, Pratylenchoides and Pratylenchus dominated with a high relative abundance percentage >60%, and were extremely common (>90% for each). The average Shannon index of nematode species in the wheat fields was 2.20, with an evenness value of 0.81, indicating moderate diversification and good nematode evenness. This study also revealed a significant correlation between nematode genus biodiversity and edaphic, climatic and geographical factors. Finally, this research demonstrated a remarkable diversity of soil nematodes associated with wheat crops and they have the potential to be useful tools for extensive soil bio-study.