Isolation and characterization of antagonistic fungi against potato scab pathogens from potato field soils

• Published in: FEMS microbiology letters Vol. 305; no. 2; pp. 136 - 142
• Main Authors: Tagawa, Masahiro, Tamaki, Hideyuki, Manome, Akira, Koyama, Osamu, Kamagata, Yoichi
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.04.2010; Blackwell Publishing Ltd; Wiley-Blackwell; Oxford University Press
• Subjects: Acidic soils; Acidification; Antagonists; Antibiosis; Bacteriology; Biological and medical sciences; Chaetomium; Cluster Analysis; Control methods; Disease control; DNA, Fungal - chemistry; DNA, Fungal - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Fundamental and applied biological sciences. Psychology; fungal antagonist; fungal antagonists; Fungi; Fungi - classification; Fungi - genetics; Fungi - isolation & purification; Fungi - physiology; Gene sequencing; Genera; Genes, rRNA; growth inhibition; Hydrogen-Ion Concentration; Microbiology; Miscellaneous; Molecular Sequence Data; Mycology; Pathogens; pH effects; Phages; phylogenetic analysis; Phylogeny; Plant diseases; Plant Diseases - microbiology; plant pathogenic bacteria; potato scab disease; Potatoes; RNA, Fungal - genetics; RNA, Ribosomal, 18S - genetics; rRNA 18S; Scab; Sequence Analysis, DNA; Soil acidification; Soil Microbiology; Soils; Solanum tuberosum - microbiology; Strains (organisms); Streptomyces; Streptomyces - growth & development; Streptomyces - pathogenicity; Vegetables; phylogenetic analysis; plant pathogenic bacteria; growth inhibition; potato scab disease; fungal antagonist; Plant pathogen; Solanum tuberosum; Cultivated soil; Phylogeny; Fungi; Dicotyledones; Angiospermae; Bacteria; Isolation; Spermatophyta; Tuber plant; Solanaceae
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2010.01928.x

Potato scab is a serious plant disease caused by several Streptomyces sp., and effective control methods remain unavailable. Although antagonistic bacteria and phages against potato scab pathogens have been reported, to the best of our knowledge, there is no information about fungi that are antagonistic to the pathogens. The aim of this study was to isolate fungal antagonists, characterize their phylogenetic positions, determine their antagonistic activities against potato scab pathogens, and highlight their potential use as control agents under lower pH conditions. Fifteen fungal stains isolated from potato field soils were found to have antagonistic activity against three well-known potato scab pathogens: Streptomyces scabiei, Streptomyces acidiscabiei, and Streptomyces turgidiscabiei. These 15 fungal strains were phylogenetically classified into at least six orders and nine genera based on 18S rRNA gene sequencing analysis. These fungal isolates were related to members of the genera Penicillium, Eupenicillium, Chaetomium, Fusarium, Cladosporium, Mortierella, Kionochaeta, Pseudogymnoascus, and Lecythophora. The antagonistic activities of most of the fungal isolates were highly strengthened under the lower pH conditions, suggesting the advantage of combining their use with a traditional method such as soil acidification. This is the first report to demonstrate that phylogenetically diverse fungi show antagonistic activity against major potato scab pathogens. These fungal strains could be used as potential agents to control potato scab disease.