On two closely related species of the Xiphinema americanum-group: X. simile

Several populations of Xiphinema simile Lamberti, Choleva et Agostinclli, 1983 and two of X. parasimile Barsi et Lamberti, 2004, originating from various habitats - natural and man-made, have been studied. Xiphinema simile was associated both with cultivated and naturally growing plants, while X parasimile was recovered from soil around grapevine. Data on the morphological and biometrical characteristics (including juvenile stages) are presented and variations discussed. Pharyngeal bulbus; and glandularium length, vaginal and uterine characteristics were shown to be good differentiating characters. This report of X parasimile is a new record for Bulgaria as well as a new plant association for the species. The description of its male is provided for the first time. The Bulgarian population of X. parasimile showed the same pattern as the Serbian population revealed by the RFLP analyses of D1-D2 region.