|Littlefield, Jeffrey - MONTANA STATE UNIVERSITY|
|Becktell, Margot - MESA STATE UNIVERSITY, CO|
|Bean, Dan - COLORADO DEPT. OF AGR.|
|Sands, Dave - MONTANA STATE UNIVERSITY|
|Pilgeram, Alice - MONTANA STATE UNIVERSITY|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 3, 2006
Publication Date: July 3, 2006
Citation: Bruckart, W.L., Eskandari, F., Littlefield, J., Becktell, M., Aime, M.C., Bean, D., Sands, D., Pilgeram, A. 2006. Puccinia acroptili on russian knapweed in colorado, montana and wyoming. Plant Disease. 90:971. Interpretive Summary: Russian knapweed, an important weed in North America, has a disease caused by a rust fungus (Puccinia acroptili). Recently, eight collections of this fungus were obtained from Colorado, Montana, and Wyoming. All the U.S. fungi were the same and were identified as P. acroptili because they matched published descriptions. Also, they only infected Russian knapweed, and they had the same size and shape of spores as other isolates, including one previously reported from New Mexico. This is the first time P. acroptili has been reported in Colorado, Montana, or Wyoming.
Technical Abstract: Acroptilon repens (L.) DC. (Russian knapweed) is a long-lived perennial weed from Central Asia that is widely distributed in the Western United States (U.S.). Recently, eight accessions of Acroptilon rust were collected from CO, MT, and WY, to use in a comparative study with isolates from Turkey and Kazakhstan. Each accession from the U.S. had two-celled teliospores with slight constrictions in the middle and urediniospores with 3 germ pores + equatorial in location. Based on fungal host plant, and both spore morphology and measurements, the latter falling within ranges described by D.B.O. Savile, these have been identified as P. acroptili and represent new reports of fungal distribution.