| Abstrakt: |
Two populations of the genus Trophotylenchulusand 10 species of the genus Paratylenchusfrom Iran were characterized based on morphometric, morphological and molecular characters. Our observations on the two populations of Trophotylenchulusfrom Iran revealed that T. asoensisand T. okamotoihave been distinguished from T. arenarius, on the basis of the features which cannot be longer considered as stable diagnostic characters. One of the populations shows a mixed combination of the characters of T. arenariusand T. asoensis; it has morphometrics more similar to T. arenariusbut shows affinities with T. asoensisin the tail terminus shape of females and second-stage juveniles (J2) and in having a reduced stylet in males. The other population fit well with T. okamotoi; it has females with generally bluntly rounded tails typical for T. okamotoi, but sometimes with finely rounded tail termini, like those of T. arenariusor T. asoensis. The sequences of D2–D3 expansion segments of 28 S rRNA gene for the two populations are identical with each other, but only 4 bp (0.67%) difference with T. arenariussequence deposited in the GenBank. Considering no stable difference allow separating species, synonymy of T. asoensisand T. okamotoiwith T. arenarius, which has already been proposed, is supported and confirmed here. All studied Paratylenchusspecies with stylets longer than 40 µm, except P. straeleni, formed a basal cluster to Cacopaurus pestisand species of Paratylenchusbearing stylets shorter than 40 µm; thus, validity of Gracilacuscannot be rejected using our data sets. However, the synonymy of Paratylenchoideswas supported by the positioning of P. sheriwithin representatives of Paratylenchusin the inferred phylogenetic tree. |
