Abstract Detail

Host/Plant Pathogen Interactions and Plant Health Management

Cao, Tiesen [1], Hwang, Sheau-Fang [2], Strelkov, Stephen. E. [1].

Differentiation of Plasmodiophora brassicae populations and single-spore isolates using CAPS markers.

The soilborne parasite Plasmodiophora brassicae Woronin causes clubroot, an important disease of cruciferous crops. Physiologic specialization exists in populations of P. brassicae, and pathotype 3 (as defined on the differentials of Williams) is predominant on canola (Brassica napus) in Alberta, Canada. However, a novel strain of the pathogen, pathotype 5x, has been recently identified in this region. Unlike pathotype 3, pathotype 5x is virulent on all clubroot resistant canola cultivars available in Canada. The objective of this study was to develop cleaved amplified polymorphic sequence (CAPS) markers to distinguish pathotypes 3, 5x and a collection of other P. brassicae isolates and populations representing pathotypes 2, 5, 6 and 8. A total of 24 single-spore isolates and 7 populations were included in the analysis. The P. brassicae-specific primers PbsF1 and PbsR1, designed based on a small subunit ribosomal RNA gene sequence from the pathogen, amplified a major polymerase chain reaction (PCR) product 2120 bp or 1746 bp in size from P. brassicae-infected roots. Digestion of the amplicon with PvuII yielded a characteristic fragment of 1438 bp in size from tissues infected with P. brassicae isolates representing pathotype 6, whereas a 1064 bp band was obtained from isolates representing pathotypes 2, 3, 5, and 8. In populations of the novel pathotype 5x, the primers amplified two major and distinctive fragments about 2000 bp and 3000 bp in size. Digestion of these amplicons with PvuII also yielded distinctive banding patterns. These CAPS markers have good potential as tools to distinguish pathotypes of P. brassicae.

1 - University of Alberta, Department of Agricultural, Food and Nutritional Science, 116 St. and 85 Ave, Edmonton, AB, T6G 2P5, Canada
2 - Alberta Agriculture and Rural Development, Research and Innovation, Crop Diversification Centre North, 17507 Fort Road, Edmonton Alberta, AB, T5Y 6H3, Canada

Keywords:
Plasmodiophora brassicae
pathotype
Molecular markers.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PPA003
Abstract ID:1272
Candidate for Awards:None