Skip to main content
ARS Home » Research » Publications at this Location » Publication #183749
Title: FIRST REPORT OF PHRAGMIDIUM VIOLACEUM INFECTING HIMALAYA AND EVERGREEN BLACKBERRIES IN NORTH AMERICA

Author
item OSTERBAUER, N - ODA, SALEM, OR.
item TRIPPE, A - ODA, SALEM, OR.
item FRENCH, K - ODA, SALEM, OR.
item BUTLER, T - ODA, SALEM, OR.
item Aime, Mary
item BRUCKART, W - USDA-ARS, FT DIETRICK,MD
item PEERBOLT, T - PORTLAND, OR
item KAUFMAN, D - AURORA, OR

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2005
Publication Date: 9/23/2005
Citation: Osterbauer, N., Trippe, A., French, K., Butler, T., Aime, M.C., Bruckart, W., Peerbolt, T., Kaufman, D. 2005. First report of Phragmidium violaceum infecting Himalaya and Evergreen Blackberries in North America. Plant Health Progress doi:10.1094/PHP-2005-0923-01-BR.

Interpretive Summary: Rust fungi are parasites that cause diseases on crop and native plants and trees throughout the world. Species of rust fungi can be transported into the United States and cause diseases as invasive species. Recently a rust fungus was found causing a dieback disease on plants of blackberry and raspberry (Rubus spp.) in Oregon. The fungus was identified using both morphological and molecular characteristics as a rust species that has never been known previously in North America. A survey of blackberry and raspberry in Oregon has revealed that this rust fungus occurs in a number of places in the state. As yet, it has not been determined whether the fungus was overlooked or has been recently introduced. This research will be used by plant pathologists and agronomists to determine how to control this rust disease of blackberry and raspberry.

Technical Abstract: In May and June of 2004, ranchers in Curry County, Oregon observed dieback in Himalaya blackberry (Rubus armeniacus Focke) caused by a rust fungus most closely resembling Phragmidium violaceum. Molecular sequencing of the ribosomal internal transcribed spacer region-2 (ITS-2) and the ribosomal 28S large subunit gene region was used to accurately identify this species. Caneberry growers in the mid- and northern Willamette Valley of Oregon also noticed a rust-like fungus infecting commercially grown evergreen blackberry (Rubus laciniatus Willd.) ‘Ever Thornless’ in the late summer of 2004. As with the rust on the Himalaya blackberry, the morphological identification was confirmed by an USDA official identifier and by sequencing the ribosomal DNA. Phragmidium violaceum occurs on several species of Rubus, including R. armeniacus, R. fruticosus agg. and R. laciniatus, in Europe, South Africa, Iran and Iraq, and has been introduced as a biological control agent for invasive blackberries in Australia, New Zealand, and Chile. This is the first official report of P. violaceum infecting Himalaya and evergreen blackberries in North America.