Abstract
During a survey on the biodiversity of plant-parasitic nematodes in citrus orchards of Khuzestan province (Southwestern Iran), 97 root and soil samples were collected. Nematodes were extracted and identified using morphological and morphometric diagnostic characters. Six nematode species were identified, namely: Helicotylenchus abunaamai, H. crenacauda, Pratylenchus allius, P. musii, Psilenchus hilarulus and Tylenchulus semipenetrans. Except T. semipenetrans, the remaining five species were found only in the rhizosphere of citrus, not in citrus roots, and their pathogenicity on citrus plants was not further studied. This is the first record of P. allius and P. musii for the nematode fauna in Iran. H. crenacauda is a new record for the nematode fauna in the Khuzestan province and is reported for the first time in citrus orchards in Iran. To our knowledge, this is the first report of H. abunaamai in citrus orchards worldwide.