NEW MORPHOLOGICAL OBSERVATIONS ON PRATYLENCHUS THORNEI SHER & ALLEN, 1953 (NEMATODA PRATYLENCHIDAE) BASED ON THE POPULATION FROM IRAN

Abstract

A population of Pratylenchus thornei was recovered from the rhizospheric soil of sugarcane in Khuzestan province, southwest Iran. It was studied using morphological and molecular data and new morphological observations were made. This population is characterized by 457-551 μm long females, lateral field with five or six smooth incisures, lip region with three annuli, stylet 14.0-16.8 μm long with rounded basal knobs, spermatheca empty, tail subcylindrical and slightly conical towards tip, tail terminus truncate, subdigitate, trilobed or indented. Comparisons with some previously reported populations and similar species are discussed. This is the first report of the species from sugarcane fields in Iran. The molecular phylogenetic analyses were done by using partial sequences of the D2-D3 expansion segments of large subunit, and internal transcribed spacer (LSU D2-D3 and ITS rDNA) regions. The studied population of the species formed a maximally supported clade with other sequences of the species in both phylogenetic analyses using Bayesian inference