Fungi colonizing microsclerotia of Verticillium dahliae in urban environments

Fungi that colonize microsclerotia of the plant pathogen Verticillium dahli ae were surveyed from a number of natural habitats in order to identify pot ential hyperparasites of the pathogen in urban environments. Microsclerotia of V. dahliae were buried in soil at the field sites and the fungi that co lonized the microsclerotia were isolated on a variety of media and identifi ed to species based on morphology and DNA (internal transcribed spacers of nuclear rDNA) sequences. Twenty-seven fungal species among 70 isolates were identified, including known mycoparasites of V. dahliae and other fungi. T hirteen of the 27 species were found across multiple field sites, whereas f ourteen species were limited to a single location. Species appearing at 3 o r more different locations included Alternaria alternata, Trichoderma konin gii, Fusarium solani, Trichoderma hamatum, Trichoderma harzianum, Zygorhync hus moelleri, and Clonostachys rosea. Chi-square analysis showed that three species, A. afternata, T. koningii, and Fusarium oxysporum, occurred at fr equencies significantly greater (p <0.05) than expected, suggesting that th ey have a higher affinity for microsclerotia of V. dahliae than other fungi . This study provides a list of potential mycoparasites of microsclerotia o f the pathogen V. dahliae in urban environments.