Submitted to: Nematropica
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/19/2005
Publication Date: 11/1/2005
Citation: Inserra, R., Duncan, L., Dunn, R., Handoo, Z.A., Troccoli, A., Rowe, J. 2005. Pratylenchus jordanensis, a junior synonym of p. zeae. Nematropica. 35(2):161-170. Interpretive Summary: Nematodes are microscopic worms that cause ten billion dollars of crop losses in the United States each year. Lesion nematodes are one of the most economically destructive groups of plant-parasitic nematodes. A major problem with determining the damage caused by specific lesion nematodes is that methods for their identification and their geographic distribution are inadequately known. In the present study, a collaboration of an ARS scientist from Beltsville, Maryland, together with researchers from Florida, Italy, and England, discovered new anatomical features for distinguishing a previously described lesion nematode species from several closely related species. These anatomical features, obtained with both light microscopes and high-powered electron microscopes, include shapes of the lip ridges, head, and tail. The results are significant because they provide the details necessary for scientists to correctly identify this species wherever it may occur in the world. This research will be used by scientists, action agencies, and extension agencies engaged in nematode research and control.
Technical Abstract: Pratylenchus jordanensis paratypes from the Rothamsted Nematode Collection in England and three populations from Oman deposited at the USDA Nematode Collection, Beltsville, U.S.A., were used for morphological analyses by light (LM) and scanning electron microcopy (SEM). Morphometrics and tail shape of P. jordanensis paratypes and populations from Oman were determined and compared with those reported in the literature for P. zeae. Head patterns of P. jordanensis and P. zeae were examined by SEM using a 20-year-old P. jordanensis paratype removed from the original collection slide and specimens of an Oman population from grapevine, and a Florida population of P. zeae from St. Augustine grass. Head patterns of the P. jordanensis specimens showed a smooth face with oral disc and lip sectors fused together and three lip annuli like those of P. zeae. The margin of the third lip annulus was interrupted by an incisure in both the P. jordanensis paratype and P. zeae. The morphological similarities between P. jordanensis and P. zeae suggest that P. jordanensis is a junior synonym of P. zeae.