Multi-Marker Approach for the Identification of Different Heterodera Species (Nematoda: Heteroderidae)

Cyst nematodes of the genus <i>Heterodera</i> are important plant-parasitic nematodes that cause significant crop losses worldwide but are often overlooked due to their non-specific symptoms and complex biology. This study assessed <i>Heterodera</i> diversity in Portugal using an integrative molecular approach based on four genetic markers (mt<i>COI</i>, 18S rDNA, ITS, and 28S rDNA). Five valid species were identified: <i>Heterodera cruciferae</i>, <i>H. mani</i>, <i>H. schachtii</i>, <i>H. trifolii</i>, and <i>H. zeae</i>, with <i>H. mani</i> reported for the first time in the country. A distinct taxon from Coimbra (central Portugal) may represent a new or unsequenced species, highlighting gaps in reference datasets. Among the markers, mt<i>COI</i> was the most effective, though some taxa remained unresolved. These results reinforce the value of multi-marker approaches, contribute with new sequences, and improve diagnostic capability for nematode management.