Morphology and Molecular Characteristics of Pratylenchus japonicus (Ryss, 1988) n. stat. (Nematoda, Pratylenchidae)

Pratylenchus macrostylus japonicus Ryss, 1988 is elevated to the specific rank as P. japonicus, a new status based on the morphological differences observed by an optical and scanning electronic microscope. This species was primarily distinguished from P. macrostylus Wu, 1971 by having shorter spear (18-2 1 μrn vs. 21-28 μm). Obvious morphological differences are: i) steadily cask-shaped vestibule extension of cephalic frame work in P. japonicus instead of simple widening vestibule extension in P. macrostylus; ii) undivided en face pattern (Group 1) in P. japonicus instead of differentiated median segment (Group 2) in P. macrostylws, iii) much reduced median inner sensilla at the margins of oral aperture in P. japonicus instead of normal sensilla in P. macrostylus, iv) lip region continuous to body contour in P. japonicus instead of offset lip region in P. macrostylus. and v) three lip annuli in P. japonicus instead of two in P. macrostylus. The PCR amplification product, including two ITS regions, a 5.8s gene, and small portions of the 18s and 28s genes of the rDNA obtained using F194 and F195 primers, was a single fragment of about 800 bp. The restriction patterns and the DNA fragment sizes obtained after digestion of 10 endonucleases Alu I, Dde I, Hha I, Hinf I, Taq I, Hue III, Mbo I, Nsp V. Pst I, and Sau 96 I were presented