First report of lily root rot caused by Thanatephorus cucumeris AG 2-1 in the United States.
A survey was undertaken on April 2016 to profile soilborne fungal pathogens causing root rot and lesions on lily (Lilium longiflorum) cv. Nellie White in Brookings, Curry County, Oregon, USA. Diseased roots were either blackened or rotted. Recently, the presence of pathogenic Fusarium oxysporum, F. tricinctum and Ceratobasidium sp. AG-I isolates in eight randomly selected fungal isolates from diseased roots of lilies was demonstrated. In this investigation, three additional fungal isolates showed four to six nuclei per cell under the microscope. Based on morphological characteristics, DNA sequence analysis and pathogenicity tests, the isolates were identified as Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) anastomosis group (AG) 2-1. This is thought to be the first report of T. cucumeris AG 2-1 causing root rot of lily in the field plots of Oregon or anywhere else in the USA.