Abstract Detail

Ecology/Pathology

Demers, Jill [1], Crouch, Jo Anne [1], Castlebury, Lisa A. [1].

Real-time PCR as a tool for identification of rust specimens.

Rust fungi are obligate biotrophs that are challenging to work with thus the development of identification tools has lagged behind that of other common pathogenic fungi. Real-time PCR is highly sensitive and uses small amplicon sizes, which makes it ideal for use with samples containing fragmented and/or low concentrations of target DNA. A real-time PCR assay was developed using freshly collected specimens of Puccinia chrysanthemi and sequence data from GenBank.  This assay was used to determine the identities of 197 specimens from the U. S. National Fungus Collections from diverse sources.  Included among the specimens were many from Japan, thought to be the origin of P. chrysanthemi, and historical samples dating to the first outbreaks in the United States in 1896. The assay yielded positive detections from 98% of the specimens morphologically identified as P. chrysanthemi, showing that potential fragmentation of the herbarium DNA did not prevent amplification by real-time PCR. The assay was not positive for similar rust fungi on non-Chrysanthemum hosts, suggesting that P. chrysanthemi is limited to Chrysanthemum, and the assay was also not positive for the more distantly related Puccinia horiana, also occurring on Chrysanthemum. In addition to enabling accurate identification and determination of host range and geographic distribution for older specimens in herbaria, real-time PCR markers may allow reconstruction of the movement of P. chrysanthemi or other invasive rust fungi using population specific markers. This technique minimizes the amount of material needed from old and potentially valuable specimens while providing potentially new information about historical samples.

1 - USDA-ARS, Systematic Mycology and Microbiology Laboratory, 10300 Baltimore Avenue, Building 010A, Beltsville, MD, 20705, USA

Keywords:
real-time PCR
Rust fungi.

Presentation Type: Offered Paper - Paper
Session: 16
Location: Room 104 AB/Kellogg Hotel and Conference Center
Date: Wednesday, June 11th, 2014
Time: 11:30 AM
Number: 16005
Abstract ID:154
Candidate for Awards:None