Canadian Journal of Plant Pathology (2014) 36, 89-99

Gary Peng, Kevin C. Falk, Richard K. Gugel, Coreen Franke, Fengqun Yu, Brian James, Stephen E. Strelkov, Sheau-Fang Hwang and Linda McGregor (2014)
Sources of resistance to Plasmodiophora brassicae (clubroot) pathotypes virulent on canola
Canadian Journal of Plant Pathology 36 (1), 89-99
Abstract: A collection of 955 Brassica accessions including B. rapa (718), B. napus (94), B. juncea (93), B. oleracea (30), B. carinata (12) and B. nigra (8) was screened against Plasmodiophora brassicae pathotype 3 (1 × 10⁶ resting spores cc⁻¹ growth medium), the predominant strain of the pathogen on canola in western Canada. A total of 35 accessions (mostly B. rapa) showed at least 50% reduced clubroot severity relative to a susceptible control, with 15 showing complete resistance (clubroot-free). Ten resistant accessions representing Brassica A-, B- and C-genome species were tested further using a 10-fold higher pathogen inoculum dose (1 × 10⁷ resting spores cc⁻¹ growth medium) and by testing them against the five pathotypes (2, 3, 5, 6 and 8) of P. brassicae found in Canada. One B. nigra, two B. oleracea and four B. rapa (oriental vegetable) accessions maintained a high level of resistance under the higher pathogen inoculum pressure, while one B. nigra and two B. rapa (turnip) accessions showed moderate resistance. Most of the selected clubroot-resistant accessions showed consistent resistance to each of the five P. brassicae pathotypes found in Canada, except for one B. nigra and two turnip accessions, which varied slightly against different pathotypes. Several promising sources of clubroot resistance were identified in this study that can be used to develop new canola germplasm with a diverse clubroot resistance background for potentially more durable clubroot resistance.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Gary Peng, Stephen E. Strelkov, Feng-Qun Yu

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plasmodiophora brassicae	Rape/canola (Brassica napus)	Canada (west)