Submitted to: Nematropica
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/1997
Publication Date: N/A
Technical Abstract: A population of potato cyst nematodes was discovered near Prattsburg, New York that reproduced freely on potato cultivars carrying the H1 gene for resistance to Globodera rostochiensis pathotype Ro1 . An isolate of this variant population was increased on the Ro1 resistant potato cultivar Hudson and tested for color sequence during cyst maturation, examined morphologically, and subjected to differential host tests. Color sequence during cyst maturation of this isolate paralleled that of G. rostochiensis with short white (1 wk) and yellow (1 wk) phases followed by a longer (2 wks) golden phase before turning brown. Morphometrics of males, females, and juveniles of the variant isolate were within the range of those for G. rostochiensis. Differential hosts consisting of different potato genotypes that are used in the international scheme to distinguish pathotypes of potato cyst nematodes were obtained from the International Potato Center, Lima, Peru. In tests with these differential hosts, the isolate from the variant population reproduced freely on the standard susceptible differential host (Solanum tuberosum spp. tuberosum) and the differential host with the H1 gene for S. tuberosum spp. andigena but did not reproduce significantly on any of the other genotypes . According to the international pathotyping scheme for potato cyst nematodes, this pattern of reproduction on these differential hosts is typical of G. rostochiensis pathotype Ro2.