Responses of potato cultivars to the common scab pathogens, Streptomyces scabies and S. turgidiscabies |
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Authors: | L H HILTUNEN A WECKMAN A YLHÄINEN H RITA E RICHTER J P T VALKONEN |
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Institution: | Plant Pathology Laboratory, Department of Applied Biology, PO Box 27, FIN-00014 University of Helsinki, Finland;Department of Forest Resource Management, PO Box 27, FIN-00014 University of Helsinki, Finland |
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Abstract: | A glasshouse experiment was conducted to study the responses to Streptomyces scabies and S. turgidiscabies in potato cultivars Bellona, Matilda and Sabina (Solanum tuberosum). Potatoes were grown in a peat‐sand mixture inoculated with one of the two strains of either S. scabies or S. turgidiscabies. Logit models were used to analyse the data on disease incidence and severity, whereas the data on emergence and yield were tested by analysis of variance. S. turgidiscabies, a recently described potato pathogen in Finland, possessed a high ability to cause superficial, raised and pitted lesions on all three cultivars tested. Symptoms induced by S. turgidiscabies were similar to those of S. scabies, regardless of the cultivar, which suggests that the two causal organisms of common scab cannot be distinguished based on symptoms. Infection by S. turgidiscabies and S. scabies delayed emergence, had the tendency to decrease the yield, and increased the proportion of small tubers in the yield, regardless of the potato cultivar. Differences in the levels of resistance to common scab were evident between potato cultivars, since cvs. Matilda and Bellona showed higher disease incidence and more severe scab symptoms than cv. Sabina. |
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Keywords: | Streptomyces scabies Streptomyces turgidiscabies common scab potato Solanum tuberosum logit models |
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