Serological Detection and Identification of Streptomyces ipomoea. J. W. Moyer, Associate Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27695-7616. E. Echandi, Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27695-7616. Plant Dis. 70:516-518. Accepted for publication 26 December 1985. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-516.

Antiserum was produced to Streptomyces ipomoea, using unfractionated cellular homogenates as the immunogen. Antibodies to antigens common to S. ipomoea and closely related organisms were removed by cross-absorption of the antiserum with extracts from selected strains. Selection of strains was based on antigens detected by western blot analysis, which revealed distinct qualitative differences in antigens shared between S. ipomoea and the other strains. Both gel diffusion and ELISA serological tests were used to identify S. ipomoea in pure cultures. However, the sensitivity of ELISA was necessary to detect S. ipomoea in symptomatic root tissue. The assay was compared with accepted isolation procedures using 114 symptomatic roots collected from 10 fields. S. ipomoea was detected in 107 samples by ELISA and in 109 samples by isolation.