First report of common scab on potato caused by Streptomyces europaeiscabiei in Taiwan

Common scab caused by Streptomyces spp. is an economically important disease of potato (Solanum tuberosum L.) worldwide. In Taiwan, only S. scabies has been reported as the causal species of common scab on potato tubers. In spring of 2015 and 2016, potato tubers of cv. Kennebec with scab symptoms were collected from 14 fields in Taichung city, Yunlin County and Chiayi County. Bacteria were isolated from scab lesions using International Streptomyces Project medium 4 (ISP medium 4). Colonies with white to grey spores were transferred to a new ISP medium 4 after 7 days. Pure cultures of isolates were obtained by 3 times transferring of single colony. Genomic DNA of pure culture bacteria was extracted by NaOH-based method (Wang et al. 1993) and used as template for PCR with species-specific primers for 16S rRNA gene sequences of S. scabiei, S. turgidiscabiei and S. acidiscabiei. (Leiminger et al. 2013). Of the 33 bacterial isolates recovered, 31 isolates had amplified segments of S. scabies and two remained u...