Isolation and identification of pathogenic strains of Streptomyces acidiscabies from netted scab lesions of potato tubers in Hokkaido (Japan).

A relatively homogeneous group of streptomycete isolates was obtained from netted scab lesions of potato tubers collected from a potato field in Hokkaido, Japan. Based on 55 phenotypic data of 72 Streptomyces strains selected from these isolated together with spectral data on their soluble pigments and with data of a PCR analysis, using species specific primers, these netted scab causing pathogenic organisms were identified as S. acidiscabies. S. acidiscabies had previously been isolated from deep (common) scab lesions in the USA and reported as thaxtomin A producer. In contrast, our S. acidiscabies strains were not able to induce deep scab symptoms on potato minitubers in pot test, did not produce the phytotoxin thaxtomin A and did not contain the pathogenicity related gene, nec-1.