First report of stem blight caused by Calonectria colhounii (anamorph Cylindrocladium colhounii) on greenhouse-grown blueberries in the United States.

摘要

Necrotic stems and leaves were observed on 2- to 4-month-old, rooted microshoot plants (Vaccinium corymbosum, V. angustifolium, and V. corymbosum x V. angustifolium) in Michigan greenhouse in 2008 and 2009. As the disease progressed, root rot were observed and leaves fell off and 80 to 100% of the plants died in some cases. A fungus was isolated from stem lesions. On the basis of morphology, the fungus was identified as Calonectria colhounii. The internal transcribed spacer region (ITS1 and ITS2) of the ribosomal DNA and the Beta -tubulin gene sequence shared 97% maximum identity with that of C. colhounii CBS 114036 (DQ190560) isolated from leaf spots on Rhododendron sp. in North Carolina. This is thought to be the first report of C. colhounii causing a disease of blueberry in Michigan or the United States.