First report of Acrostalagmus luteo-albus causing red rust of needle mushroom (Flammulina velutipes) in China.
From 2009 to 2010, red rust-colored sporulation (fungal mycelia and conidia) was found on the substrate surface of white needle mushroom (F. velutipes) bags in more than 10 mushroom cultivation operations in Hebei, China. The rust-coloured sporulation covered the substrate surface, where the development of the fruiting bodies was inhibited; the stipes were sparse and became light brown when the substrate was slightly affected. The fruiting bodies on severely affected substrate were unable to complete development or shriveled and died off on the substrate. More than 30 to 40% substrate bags were contaminated with the red rust mold, with approximately a 40% yield reduction in each production house. Based on morphological characteristics, sequence analysis of the rDNA internal transcribed spacer region and pathogenicity tests, the causal agent was identified as A. luteo-albus [A. luteoalbus]. This fungus has been associated with postharvest rot of ginger rhizomes in Brazil. This is thought to be the first report of A. luteo-albus causing damage to needle mushroom in China.