Investigation-Research: Differentiation of Two Geographically Isolated Populations of Pratylenchus neglectus Based on Their Parasitism of Potato and Interaction with Verticillium dahliae


  • S. L. Hafez
  • S. Al-Rehiayani
  • M. Thornton
  • P. Sundararaj


Intraspecific Variation, Potato, Pratylenchus neglectus, Verticillium dahliae


Relationships of two populations of Pratylenchus neglectus, one from Parma, Idaho (IPN) and the other from Ontario, Canada (CPN) to Russet Burbank potato and Verticillium dahliae (Vd) were evaluated. Early egression of IPN and CPN was measured on a resistant potato cultivar (Butte). Egression of CPN from Butte roots was lower (79.4%) than that of IPN (93.7%). CPN reproduced faster and averaged twice the population size on cultivars Russet Burbank and Butte (P 0.05) compared to IPN. IPN with Vd had an effect on tuber yield that was similar to the effect of Vd alone, while the interaction of P. penetrans (PP) or CPN with Vd was greater than that of Vd alone. Area under the disease progress curve (AUDPC) for plants grown in soil infested with P. penetrans plus Vd was higher (P 0.05) than those for Vd alone or IPN plus Vd. AUDPC values produced by CPN plus Vd were not different from those produced by P. penetrans plus Vd (P 0.05). IPN, CPN and P. penetrans did not affect root and shoo