Investigation-Research: Molecular and Morphological Analysis of Isolates of Pratylenchus coffeae and Closely Related Species
Authors
L. W. Duncan
R. N. Inserra
W. K. Thomas
D. Dunn
I. Mustika
L. M. Frisse
M. L. Mendes
K. Morris
D. T. Kaplan
Keywords:
Molecular Evolution, Morphology, Morphometrics, Nematode Phylogeny, Pratylenchus coffeae, P. gutierrezi, P. loosi, P. pseudocoffeae, Ribosomal DNA, Systematics, Taxonomy
Abstract
Morphological and genome variation between 32 nematode isolates identified originally as Pratylenchus coffeae, P. gutierrezi, P. loosi, and P. pseudocoffeae were characterized to estimate phylogenetic relationships among them. All isolates have numerous males, and two lip annuli. Viewed en face with scanning electron microscopy, the first lip annulus is divided into lateral and median sectors in several isolates from coffee (Central America and Indonesia), and in one from aster (Florida). The first lip annulus is smooth in all other isolates, including six from coffee (Brazil and Indonesia). Principal component analysis (PCA) of one morphological (smooth face vs divided face) and three weakly-allometric morphometric variables (V, a, length of stylet) revealed seven assemblages of isolates. The PCA-derived assemblages conform closely to phylogenetic relationships inferred from analysis of 28S rDNA sequences. Nevertheless, identity within the D2/D3 expansion segment was not absolute fo
