Occurrence of Sheraphelenchus sucus (Nematoda: Aphelenchoidinae) and Panagrellus sp. (Rhabditida: Panagrolaimidae) Associated with Decaying Pomegranate Fruit in Italy

摘要

Two different nematode species were recovered from pomegranate decaying fruit in two localities in Southern Italy: the mycetophagus nematode Sheraphelenchus sucus and a bacterial feeder nematode belonging to the Panagrolaimidae (Rhabditida) family.Morphometrics of the Italian population of S.sucus closely resemble that of the type population, whereas some differences werefoundwhencomparedwithanotherpopulationfromIran.MolecularcharacterizationoftheItalianS.sucus usingthe18SrRNA gene, D2–D3 expansiondomains of the 28S rDNA, theITS region,and the partialmitochondrial COI were carriedout.Sequencesof the 18S rRNA gene, the D2–D3 domains,and the ITS were analyzed using several methods for inferringphylogenyto reconstruct the relationships among Sheraphelenchus and Bursaphelenchus species.The bacterial feeder Panagrellus sp.was characterized at the molecular level only.The D2–D3 expansion domains and ITS sequences of this Italian panagrolaimid were determined.The D2–D3 sequences of the Italian panagrolaimid showed 99 similarity with the corresponding sequence of Panagrellus sp.associated with Rhynchophorus ferrugineus.This is the first report on the tritrophic association of S.sucus and Rhabditida that uses both insects and pomegranate fruit as hosts.