associated with raspberry, Pratylenchus penetrans , the root lesion nematode, is the most economically important ( McElroy, 1991 ). Feeding on roots by Pratylenchus penetrans (Cobb) Filipjev and Schuurmans Stekhoven can reduce the capacity of the plant to
Inga A. Zasada and Patrick P. Moore
Yunliang Peng, Wanrong Chen and Maurice Moens
Methods to screen for resistance to root-lesion nematode Pratylenchus penetrans in Rosa were modified to screen-rooted materials. Sixty days after rooting, plants were transplanted into 50-mL pots filled with river sand and each inoculated with 500 P. penetrans in 400 μL water 10 days later. The inoculated plants were fertilized weekly and incubated in a growth chamber or a greenhouse for 5 months when nematodes were extracted from the sand and root system and enumerated. When used for screening of the 131 Rosa accessions, this approach allowed the observation of a large variation in host suitability. While a majority of the accessions supported the multiplication of P. penetrans, previously reported resistance of R. multiflora `K1' and R. virginiana to P. penetrans was confirmed. Rosa laevigata anemoides allowed a significantly lower nematode multiplication than the currently prevalent rootstock R. corymbifera `Laxa'.
Alan W. McKeown, John W. Potter, Mary Gartshore and Peter Carson
Root lesion nematodes (Pratylenchus penetrans Cobb) are well-adapted to sandy soils and have a host range including most agronomic, horticultural, and wild species grown in Ontario. As native climax sand-prairie species have coexisted with the nematode for millennia, resistance or tolerance may have developed. We have screened using the Baermann pan technique, soil samples taken from a private collection of sand-prairie species collected from local prairie remnants. Several species [Liatris cylindracea Michx., Monarda punctata L., Pycnanthemum virginianum L., Echinacea purpurea (L.) Moench] proved to be excellent hosts (>500/kg of soil) of root lesion nematode, confirming the presence of this nematode in the soil. Over two seasons, we determined that 10 plant species belonging to the families Asclepiadaceae, Compositae, Graminae, and Leguminosae to support very low numbers of P. penetrans. Brown-eyed susan (Rudbeckia hirta L.) had no root lesion nematodes throughout both seasons, Butterfly weed (Asclepias tuberosa L.) very low counts, while Switch grass (Panicum virgatum L.) and Indian grass [Sorghastrum nutans (L.) Nash] had detectable root lesion nematodes on only one sampling date each year. Big Bluestem (Andropogon gerardii Vitman), Little Bluestem [Schizachyrium scoparium (Michx) Nash], Sand Dropseed [Sporobolus cryptandrus (Torr.) Gray], Side-oats Grama [Bouteloua curtipendula (Michx.)) Torr], Broomsedge (Andropogon virginicus L.), Bush clover [Lespedeza capitata (Michx] also are poor hosts. These species have potential as cover or rotation crops useful for nematode management.
A.W. McKeown, J.W. Potter, M. Gartshore and P. Carson
Because of the need to find plants that suppress root lesion nematodes for use in rotation or cover-crops, 16 native sand-prairie species were evaluated for host status for 6 years. Plants were grown on a Fox sand soil at a local prairie plant nursery. Soil cores were taken in the spring, summer, and fall and assayed for plant parasitic nematodes. Five species supported very low numbers (less than 100/kg soil) of root lesion nematodes. Brown-eyed Susan (Rudbeckia hirta) had no detectable nematodes for the duration. Switchgrass (Panicum virgatum L.) and Indiangrass (Sorghastrum nutans L., Nash) samples produced detectable nematodes on only two sampling dates over the 6 years and were statistically not different from brown-eyed Susan. Butterfly weed (Asclepias tuberosa L.) also had very low detectable nematodes as did sand dropseed [Sporobolus cryptandrus (Torr.) Gray.]. New Jersey tea (Ceanothus americanus L.), little bluestem [Schizachyrium scoparium (Michx.) Nash], and big bluestem (Andropogon gerardi Vitman) were poor hosts with <200 nematodes/kg soil. Mountain mint (Pycnanthemum virginianum L), wild bergamont (Monarda fistulosa L), horsemint (Monarda punctata L), and dwarf blazing star (Liatris cylindracea L) all had root lesion populations over 3000/kg soil. Horsemint and wild bergamont plants died out, possibly as a result of nematode infestation. Root lesion nematodes have an extremely wide host range in current agronomic and horticultural crops, and weeds and are difficult to manage using nonchemical means. Indiangrass, switchgrass, big bluestem, and little bluestem have all been used agriculturally for pastures and consequently have potential as beneficial long-term rotation crops for nematode management and soil building.
Chrislyn Ann Particka and James F. Hancock
( Pratylenchus penetrans ) was first associated with strawberry in the early 1930s ( Steiner, 1931 ), and Townshend (1963) proved it was pathogenic to strawberry by following Koch's postulates. Although the three pathogens have been separately implicated as
Thomas W. Walters, John N. Pinkerton, Ekaterini Riga, Inga A. Zasada, Michael Particka, Harvey A. Yoshida and Chris Ishida
vertical distribution of Pratylenchus penetrans under raspberry J. Nematol. 30 179 183 Harvey, J. Han, J.C.Y. 1978 Decomposition of oxamyl in soil and water J. Agr. Food Chem. 26 536 541 Jenkins, W.R. 1964 A rapid centrifugal-flotation technique for
Rachel E. Rudolph, Thomas W. Walters, Lisa W. DeVetter and Inga A. Zasada
population trends of Pratylenchus penetrans on potato and corn Phytopathology 54 317 322 Forge, T. Muehlchen, A. Hackenberg, C. Neilsen, G. Vrain, T. 2001 Effects of preplant inoculation of apple ( Malus domestica Borkh.) with arbuscular mycorrhizal fungi
Inga A. Zasada, Thomas W. Walters and John N. Pinkerton
, Pratylenchus penetrans , on strawberry Nematropica 36 175 190 Rodríguez-Kábana, R. Kloepper, J.W. Weaver, C.F. Robertson, D.G. 1993 Control of plant parasitic nematodes with furfural: A naturally occurring fumigant Nematropica 23 63 73 Schneider, S.M. Ajwa, H
P. Gordon Braun, Keith D. Fuller, Kenneth McRae and Sherry A.E. Fillmore
spp., Rhizoctonia solani Kühn, and Pratylenchus penetrans Cobb ( Braun, 1991 ; Jaffee et al., 1982a , 1982b ; Manici et al., 2003 ; Mazzola, 1998 ; Merwin and Stiles, 1989 ). Long-term cultivation of a perennial crop, like apple [ Malus
K.S. Lewers, W.W. Turechek, S.C. Hokanson, J.L. Maas, J.F. Hancock, S. Serçe and B.J. Smith
common foliar diseases, resistance to black root rot (causal organisms unknown) ( Hancock et al., 2001b , 2002 ), and resistance to northern root-knot nematode ( Meloidogyne hapla ) and root-lesion nematode ( Pratylenchus penetrans ) ( Pinkerton and Finn