Morphological and molecular characterization of Phomopsis vaccinii and additional isolates of Phomopsis from blueberry and cranberry in the eastern United States

Abstract

Forty isolates of Phomopsis were obtained from twigs and berries of highbush blueberry, Vaccinium corymbosum, and cranberry, Vaccinium macrocarpon, isolated primarily from plants grown in the eastern United States. They were characterized using conidiomatal morphology, conidial dimensions, colony appearance and growth rate, and sequences of ITS rDNA. Based on morphological and molecular similarities, most isolates grouped together with an authentic culture of Phomopsis vaccinii Shear. This taxon is described and illustrated. However, some Phomopsis isolates from Vaccinium differed in colony and conidiomatal morphology from P. vaccinii and, based on ITS sequences, were related to isolates of Phomopsis from diverse hosts. These isolates were excluded from P. vaccinii.

• coelomycetes
• cultural characteristics
• Diaporthe
• dieback
• Ericaceae
• fungi
• ITS
• pycnidia
• Vaccinium corymbosum
• Vaccinium macrocarpon

The authors are grateful to Frank Caruso, Cranberry Experiment Station, East Wareham, Massachusetts, for isolates of Phomopsis, to Bill Cline, North Carolina State University, Castle Hayne, for access to diseased blueberry plants, and to Anjeli Sonstegard and Douglas Linn for sequencing isolates used in this study. Brenda Paul enthusiastically provided technical assistance in managing the maintenance and growth studies of the cultures