First report of Armillaria root disease caused by Armillaria tabescens on Araucaria araucana in Veracruz, Mexico.
In September 2007, bark samples were collected from the root collar of a single Araucaria araucana tree that had recently died and was suspected of being killed by Armillaria root disease. Disease symptoms and signs included a thinning crown and fruiting bodies at the tree base over a several-year period before tree death. The tree was located in an isolated street-tree planting within a business district on Maestros Veracruzanos Street, Xalapa, Veracruz, Mexico. One fungal isolate (MEX21WF) was obtained, which possessed 2 sequence repeat types from the intergenic spacer-1 (IGS-1) region. Based on these IGS-1 sequences, this isolate from Mexico possessed 99% nucleotide sequence identities with North American Armillaria tabescens isolates. Somatic pairing tests of the isolate with other North American Armillaria species also identified it as Armillaria tabescens. In addition, fruiting bodies were produced on the stump base in 2009 that matched morphological features of Armillaria tabescens. Based on the taxonomic evidence, it was concluded that the isolate was Armillaria tabescens. This is thought to be the first confirmed report of Armillaria tabescens causing Armillaria root disease in Mexico. Furthermore, this note represents the first report of Armillaria tabescens on Araucaria araucana, which is native to Chile and Argentina.