Description and Molecular Characterization of Criconemoides iraqicus n. sp. (Rhabditida: Criconematidae) From Iraq.

Abstract

Criconemoides iraqicus n. sp. recovered from the rhizospheric soil of pomegranate in Misan province, Iraq, is described based on morphological and molecular data. The new species is characterized by its lip region comprised of two annuli, true submedian lobes absent, pseudolips present, body annuli smooth and with few anastomoses (R = 76-79), stylet 64.6-75.3 μm long, with anchor-shaped basal knobs, excretory pore at one to three annuli posterior to the pharynx base, vulva closed, vulval lips not projecting above body contour, and tail conical with one to three terminal lobes. Based on the number of body annuli, stylet length, smooth annuli, and shape of postvulval body region, C. iraqicus n. sp. is closely similar to C. amorphus, C. ananasi, C. geraerti, C. informis, C. neoinformis, and C. tenuiannulatus. The phylogenetic relationships of the new species with representatives of the family Criconematidae were reconstructed and discussed using partial sequences of the small subunit, D2-D3 expansion segments of the large subunit, and internal transcribed spacer regions of ribosomal DNA (SSU, LSU D2-D3, and ITS rDNA) based on Bayesian inference (BI). In phylogenetic trees, sequences of the new species formed clades with corresponding sequences of C. geraerti, C. informis, Discocriconemella parasinensis, and D. sinensis with different levels of relatedness.