Submitted to: African Plant Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 10, 2001
Publication Date: January 1, 2002
Citation: Carta, L.K., Handoo, Z.A., Skantar, A.M., Van Biljon, J., Botha-Greeff, M. 2002. A redescription of pratylenchus teres khan and singh, 1974 (nemata: pratylenchidae) and a phylogenetic analysis of related species.. African Plant Protection 8: 13-24.
Interpretive Summary: Nematodes are microscopic, unsegmented soil worms that cause ten billion dollars of yearly crop loss in the U.S. Lesion nematodes are migratory, internal root-parasites that seriously damage many economic plants worldwide. A major problem with determining the damage caused by specific lesion nematodes is that their diagnostic characters, numbers, relationships and geographic distribution are inadequately known. In this study ARS scientists redescribe a lesion nematode species from two South African populations from cotton, or millet and tobacco. They vary in surface markings, spear length and number of lip annules. Both scanning electron microscope face patterns plus a molecular (DNA) character indicate a close relationship of these populations to one another but not to a nematode with similar morphology in the U.S. Photographs and measurements are provided for easier identification. The results are significant because these nematodes are not expected to be native inhabitants of the U. S. mainland, and are thus of possible quarantine interest. This research will be of use to scientists, growers, action agencies, and extension agencies in nematode research and control.
A South African population of Pratylenchus teres from cotton and a new subspecies from millet and tobacco are described with morphological observations from light and scanning electron microscopy (SEM), and with the D3 segment of the LS rDNA gene. The identical SEM lip patterns of both populations are similar to those of P. bolivianus, and the DNA sequence of both populations is moderately distant from that of P. crenatus, the originally diagnosed relative. A revised diagnosis with biogeographical implications is presented.