First Report of Additional Hosts for the Acid Scab Pathogen Streptomyces acidiscabies. D. H. Lambert, Department of Plant Biology and Pathology, University of Maine, Orono 04469. Plant Dis. 75:750. Accepted for publication 18 February 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0750A.
Speedling transplant root systems of table, fodder, and sugar beets
(Beta vulgaris L.), carrot (Daucus carota L.), turnip (Brassica rapa
L. var. rapifera), rutabaga (B. napus L. var. napobrassica (L.) Rchb.),
and radish (Raphanus sativus L.) saturated with liquid cultures of
potato strains of the acid scab pathogen Streptomyces acidiscabies
Lambert and Loria (2) or S. scabies (Thaxter) Lambert and Loria
developed typical scab symptoms in the field, including blisters, raised
lesions with pitted centers, and russeting. Both species were reisolated
on NPPC water agar and verified (2). Roots of parsnip (Pastinaca
sativa L.) and noninoculated controls appeared normal. S. acidiscabies
can thus infect known symptomatic hosts of S. scabies, excepting
parsnip, whose response to S. scabies varied in previous studies. Similar
host ranges and symptoms for the two unrelated species may result
from the ability of both to produce the toxin thaxtomin (1).