Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/17/2009
Publication Date: 8/1/2009
Citation: Forge, T., Koch, C., Pinkerton, J.M., Zasada, I.A. 2009. First Report in North America of Paratrichodorus renifer, a nematode parasite of highbush blueberry in the Pacific Northwest and Canada.Phytopathology. 99:S35. Interpretive Summary:
Technical Abstract: Between 2001 and 2008, over 150 blueberry fields were sampled for plant-parasitic nematodes in British Columbia (55), Nova Scotia (7), Washington (49) and Oregon (76). Stubby-root nematodes (Paratrichodorus spp.) were recovered from a relatively high percentage of fields, especially in BC and Northern Washington where 59 and 57% of sampled fields were positive for Paratrichodorus, respectively. Morphological evaluation indicated that the populations were comprised of P. renifer. Distinguishing features of P. renifer include: didelphic reproductive system with vulva at 55 to 60% of total body length; small transverse to pore-like vaginal opening; kidney-shaped (‘reniform’) vaginal sclerotized pieces that are not separated in lateral view; non-overlapping pharyngo-esophageal junction; excretory pore positioned slightly below pharyngo-intestinal junction; and absence of males. The ITS1 region of rDNA was amplified and sequenced from 10 nematodes from populations from BC, WA and NS. The ITS1 region was ~953 bp long. The WA population differed from the BC and NS populations at two loci, and all North American populations differed from a Belgian population (NCBI GenBank #EU827611) at 4 loci. The ITS1 region of P. renifer is 40 to 50% longer than for P. macrostylus, P. pachydermus, P. allius and P. teres, the only other Paratrichodorus species for which complete ITS1 data are available. Blueberry appears to be an excellent host for P. renifer; a BC population increased 70-fold over 14 months on ‘Chippewa’ blueberry in field microplots, and a Washington population increased four-fold over 6 months on ‘Duke’ blueberry in greenhouse pots.