First report of Didymella americana on baby lima bean (Phaseolus lunatus)

Gorny, Adrienne M. and Pethybridge, Sarah J. and Kikkert, Julie R. and Shivas, Roger G. (2016) First report of Didymella americana on baby lima bean (Phaseolus lunatus). Canadian Journal of Plant Pathology, 38 (3). pp. 389-394. ISSN 0706-0661


A new foliar disease was observed on baby lima bean (Phaseolus lunatus) in fields across western New York State, USA. The disease occurred in 10 fields with variable incidence and severity. Symptoms were initially necrotic, tan spots on leaves with red to reddish brown irregular margins that coalesced to encompass the entire leaf and cause abscission. Pycnidia were observed within the lesions. Isolations from diseased leaves yielded several pycnidial fungi, including a Didymella species. These isolates were characterized by morphology and sequencing of multiple reference genes (internal transcribed spacer (ITS), partial actin, β-tubulin (tub2), translation elongation factor 1-α (TEF), 28S rDNA large subunit (LSU), rpb2 and calmodulin). A four gene phylogeny (ITS, tub2, LSU and rpb2) showed that the isolates from baby lima bean belonged to a well-supported clade that contained the type culture of Didymella americana. Pathogenicity of the isolates on three commonly grown cultivars of baby lima bean was confirmed. Symptoms that developed on inoculated plants were similar to those observed on diseased plants in the field. This is the first report of D. americana on baby lima bean.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 18 May 2017 21:27
Last Modified: 18 Dec 2017 05:43
Uncontrolled Keywords: Didymellaceae; Dothideomycetes; lima bean; Peyronellaea; Phaseolus lunatus; Phoma;
Fields of Research (2008): 07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070308 Crop and Pasture Protection (Pests, Diseases and Weeds)
Fields of Research (2020): 30 AGRICULTURAL, VETERINARY AND FOOD SCIENCES > 3004 Crop and pasture production > 300409 Crop and pasture protection (incl. pests, diseases and weeds)
Socio-Economic Objectives (2008): B Economic Development > 82 Plant Production and Plant Primary Products > 8202 Horticultural Crops > 820215 Vegetables
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