Verticillium fungicola var. fungicola affects Agaricus bisporus cultivation in Mexico

Verticillium fungicola is responsible for dry bubble disease of the button mushroom Agaricus bisporus. Investigations performed in 2001 showed that mushroom cultures were affected by V. fungicola var. aleophilum in North American farms whereas they were affected by V. fungicola var. fungicola in European farms. The latter variety was not found in North America. Studies carried out on Verticillium isolates collected in Mexico in 2002 revealed that they belong to the variety fungicola. The hypothesis of the introduction of the variety fungicola from Europe through the import of material or machines used for mushroom cultivation is proposed.