Seed treatment of canola (Brassica napus) with the endomycorrhizal fungus Piriformospora indica does not reduce clubroot

Piriformospora Indica ◽

Brassica Crops ◽

Growth Room ◽

Treated Seed ◽

A Basidiomycete endomycorrhizal fungus, Piriformospora indica, colonizes and promotes the growth of canola and other Brassica crops, and can reduce diseases of other crops. Clubroot is an important disease of Bbrassica crops caused by the obligate, soil-borne pathogen Plasmodiophora brassicae. The effect of P. indica on clubroot severity in canola was assessed in replicated growth room studies. Seed was treated with P. indica using a proprietary process. Microscopic observation confirmed that canola roots grown from treated seed were colonized by P. indica. However, P. indica did not consistently reduce clubroot severity and did not promote the growth of canola.

Virulence Spectrum of Single-Spore and Field Isolates of Plasmodiophora brassicae Able to Overcome Resistance in Canola (Brassica napus)

Plant Disease ◽

10.1094/pdis-03-20-0471-re ◽

2021 ◽

Vol 105 (1) ◽

pp. 43-52 ◽

Cited By ~ 2

Author(s):

Homa Askarian ◽

Alireza Akhavan ◽

Victor P. Manolii ◽

Tiesen Cao ◽

Sheau-Fang Hwang ◽

...

Keyword(s):

Brassica Napus ◽

Confidence Interval ◽

Large Collection ◽

Single Spore ◽

Brassica Napus L ◽

Clubroot Resistance ◽

Field Isolates ◽

Virulence Spectrum ◽

Clubroot, caused by Plasmodiophora brassicae Woronin, is an important disease of canola (Brassica napus L.) that is managed mainly by planting clubroot-resistant (CR) cultivars. Field isolates of P. brassicae can be heterogeneous mixtures of various pathotypes, making assessments of the genetics of host–pathogen interactions challenging. Thirty-four single-spore isolates were obtained from nine field isolates of the pathogen collected from CR canola cultivars. The virulence patterns of the single-spore and field isolates were assessed on the 13 host genotypes of the Canadian Clubroot Differential (CCD) set, which includes the differentials of Williams and Somé et al. Indices of disease (IDs) severity of 25, 33, and 50% (±95% confidence interval) were compared as potential thresholds to distinguish between resistant and susceptible reactions, with an ID of 50% giving the most consistent responses for pathotype classification purposes. With this threshold, 13 pathotypes could be distinguished based on the CCD system, 7 on the differentials of Williams, and 3 on the hosts of Somé et al. The highest correlations were observed among virulence matrices generated using the three threshold IDs on the CCD set. Genetically homogeneous single-spore isolates gave a clearer profile of the P. brassicae pathotype structure. Novel pathotypes, not reported in Canada previously, were identified among the isolates. This large collection of single-spore isolates can serve as a reference in screening and breeding for clubroot resistance.

Genetics and molecular mapping of resistance to Plasmodiophora brassicae pathotypes 2, 3, 5, 6, and 8 in rutabaga (Brassica napus var. napobrassica)

Genome ◽

10.1139/gen-2016-0034 ◽

2016 ◽

Vol 59 (10) ◽

pp. 805-815 ◽

Cited By ~ 24

Author(s):

Muhammad Jakir Hasan ◽

Habibur Rahman

Keyword(s):

Brassica Napus ◽

Doubled Haploid ◽

Genetic Basis ◽

Molecular Mapping ◽

Single Gene ◽

Genomic Region ◽

Clubroot Disease ◽

Dh Population ◽

Brassica Crops

Clubroot disease, caused by Plasmodiophora brassicae, is a threat to the production of Brassica crops including oilseed B. napus. In Canada, several pathotypes of this pathogen, such as pathotypes 2, 3, 5, 6, and 8, were identified, and resistance to these pathotypes was found in a rutabaga (B. napus var. napobrassica) genotype. In this paper, we report the genetic basis and molecular mapping of this resistance by use of F2, backcross (BC1), and doubled haploid (DH) populations generated from crossing of this rutabaga line to a susceptible spring B. napus canola line. The F1, F2, and BC1 populations were evaluated for resistance to pathotype 3, and the DH population was evaluated for resistance to pathotypes 2, 3, 5, 6, and 8. A 3:1 segregation in F2 and a 1:1 segregation in BC1 were found for resistance to pathotype 3, and a 1:1 segregation was found in the DH population for resistance to all pathotypes. Molecular mapping by using the DH population identified a genomic region on chromosome A8 carrying resistance to all five pathotypes. This suggests that a single gene or a cluster of genes, located in this genomic region, is involved in the control of resistance to these pathotypes.

Identification of lncRNAs Responsive to Infection by Plasmodiophora brassicae in Clubroot-Susceptible and -Resistant Brassica napus Lines Carrying Resistance Introgressed from Rutabaga

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-12-18-0341-r ◽

2019 ◽

Vol 32 (10) ◽

pp. 1360-1377 ◽

Cited By ~ 3

Author(s):

Aarohi Summanwar ◽

Urmila Basu ◽

Habibur Rahman ◽

Nat Kav

Keyword(s):

Brassica Napus ◽

Target Genes ◽

Genome Chromosome ◽

Clubroot Disease ◽

Brassica Crops ◽

A Genome ◽

Microbe Interactions ◽

Trait Locus ◽

Plant Pathogen Interactions

Clubroot disease, caused by Plasmodiophora brassicae Woronin, is a major threat to the production of Brassica’ crops. Resistance to different P. brassicae pathotypes has been reported in the A genome, chromosome A08; however, the molecular mechanism of this resistance, especially the involvement of long noncoding RNAs (lncRNAs), is not understood. We have used a strand-specific lncRNA-Seq approach to catalog lncRNAs from the roots of clubroot-susceptible and -resistant Brassica napus lines. In total, 530 differentially expressed (DE) lncRNAs were identified, including 88% of long intergenic RNAs and 11% natural antisense transcripts. Sixteen lncRNAs were identified as target mimics of the microRNAs (miRNAs) and eight were identified as the precursors of miRNAs. KEGG pathway analysis of the DE lncRNAs showed that the cis-regulated target genes mostly belong to the phenylpropanoid biosynthetic pathway (15%) and plant–pathogen interactions (15%) while the transregulated target genes mostly belong to carbon (18%) and amino acid biosynthesis pathway (19%). In all, 24 DE lncRNAs were identified from chromosome A08, which is known to harbor a quantitative trait locus conferring resistance to different P. brassicae pathotypes; however, eight of these lncRNAs showed expression only in the resistant plants. These results could form the basis for future studies aimed at delineating the roles of lncRNAs in plant–microbe interactions.

Isolation and Variation in Virulence of Single-Spore Isolates of Plasmodiophora brassicae from Canada

Plant Disease ◽

10.1094/pdis-92-3-0456 ◽

2008 ◽

Vol 92 (3) ◽

pp. 456-462 ◽

Cited By ~ 81

Author(s):

S. Xue ◽

T. Cao ◽

R. J. Howard ◽

S. F. Hwang ◽

S. E. Strelkov

Keyword(s):

British Columbia ◽

Brassica Napus ◽

Efficient Method ◽

Breeding Strategy ◽

Single Spore ◽

Susceptible Host ◽

Significant Difference ◽

Resting Spores ◽

Clubroot of crucifers, caused by Plasmodiophora brassicae, is emerging as an important disease of canola (Brassica napus) in Alberta, Canada. Populations of the pathogen often consist of a mixture of different pathotypes. Therefore, a simple and efficient method to isolate single resting spores of P. brassicae was developed, based on serial dilution of spore suspensions. The virulence of 24 single-spore isolates, representing five populations of the pathogen from Alberta, Ontario, and British Columbia, was characterized on the differentials of Williams and Somé et al. Symptoms were rated 6 weeks after inoculation and Fisher's least significant difference (P < 0.05) was used to differentiate resistant from susceptible host reactions. The pathotype composition of P. brassicae in Canada appeared more diverse when single-spore isolates were examined rather than populations of the pathogen. In Alberta, at least three and possibly four pathotypes were identified among the 14 isolates tested, whereas a maximum of only two pathotypes had been reported previously when populations of the pathogen were examined. Pathotype 3 or P2, as classified on the differentials of Williams and Somé et al., respectively, was found to be predominant in the province. The occurrence of other pathotypes at lower frequencies suggests that caution should be used in any breeding strategy, because rare pathotypes of P. brassicae may quickly become predominant if susceptible host genotypes are continuously grown.

Current and Future Pathotyping Platforms for Plasmodiophora brassicae in Canada

Plants ◽

10.3390/plants10071446 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1446

Author(s):

Heather H. Tso ◽

Leonardo Galindo-González ◽

Stephen E. Strelkov

Keyword(s):

Crop Production ◽

Cost Effective ◽

Turnaround Time ◽

Molecular Techniques ◽

Differential Set ◽

Management Plans ◽

Increased Sensitivity ◽

Phenotypic Methods ◽

Clubroot, caused by Plasmodiophora brassicae, is one of the most detrimental threats to crucifers worldwide and has emerged as an important disease of canola (Brassica napus) in Canada. At present, pathotypes are distinguished phenotypically by their virulence patterns on host differential sets, including the systems of Williams, Somé et al., the European Clubroot Differential set, and most recently the Canadian Clubroot Differential set and the Sinitic Clubroot Differential set. Although these are frequently used because of their simplicity of application, they are time-consuming, labor-intensive, and can lack sensitivity. Early, preventative pathotype detection is imperative to maximize productivity and promote sustainable crop production. The decreased turnaround time and increased sensitivity and specificity of genotypic pathotyping will be valuable for the development of integrated clubroot management plans, and interest in molecular techniques to complement phenotypic methods is increasing. This review provides a synopsis of current and future molecular pathotyping platforms for P. brassicae and aims to provide information on techniques that may be most suitable for the development of rapid, reliable, and cost-effective pathotyping assays.

Mapping of clubroot (Plasmodiophora brassicae) resistance in canola (Brassica napus)

Plant Pathology ◽

10.1111/ppa.12422 ◽

2015 ◽

Vol 65 (3) ◽

pp. 435-440 ◽

Cited By ~ 17

Author(s):

H. Zhang ◽

J. Feng ◽

S.-F. Hwang ◽

S. E. Strelkov ◽

I. Falak ◽

...

Keyword(s):

Brassica Napus ◽

Plasmodiophora Brassicae

Endosphere microbiome comparison between symptomatic and asymptomatic roots of Brassica napus infected with Plasmodiophora brassicae

PLoS ONE ◽

10.1371/journal.pone.0185907 ◽

2017 ◽

Vol 12 (10) ◽

pp. e0185907 ◽

Cited By ~ 18

Author(s):

Ying Zhao ◽

Zhixiao Gao ◽

Binnian Tian ◽

Kai Bi ◽

Tao Chen ◽

...

Keyword(s):

Brassica Napus ◽

Plasmodiophora Brassicae

Dataset for the metabolic and physiological characterization of seeds from oilseed rape (Brassica napus L.) plants grown under single or combined effects of drought and clubroot pathogen Plasmodiophora brassicae

Data in Brief ◽

10.1016/j.dib.2021.107247 ◽

2021 ◽

pp. 107247

Author(s):

Grégoire Bianchetti ◽

Cécile Baron ◽

Aurélien Carrillo ◽

Solenne Berardocco ◽

Nathalie Marnet ◽

...

Keyword(s):

Brassica Napus ◽

Oilseed Rape ◽

Combined Effects ◽

Brassica Napus L ◽

Physiological Characterization ◽

Effects Of Drought

Emergence of new virulence phenotypes of Plasmodiophora brassicae on canola (Brassica napus) in Alberta, Canada

European Journal of Plant Pathology ◽

10.1007/s10658-016-0888-8 ◽

2016 ◽

Vol 145 (3) ◽

pp. 517-529 ◽

Cited By ~ 50

Author(s):

Stephen E. Strelkov ◽

Sheau-Fang Hwang ◽

Victor P. Manolii ◽

Tiesen Cao ◽

David Feindel

Keyword(s):

Brassica Napus ◽

Plasmodiophora Brassicae

Effects of cis-Jasmone Treatment of Brassicas on Interactions With Myzus persicae Aphids and Their Parasitoid Diaeretiella rapae

Frontiers in Plant Science ◽

10.3389/fpls.2021.711896 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jamin Ali ◽

Anca D. Covaci ◽

Joe M. Roberts ◽

Islam S. Sobhy ◽

William D. J. Kirk ◽

...

Keyword(s):

Brassica Napus ◽

Myzus Persicae ◽

Methyl Salicylate ◽

Plant Defence ◽

Diaeretiella Rapae ◽

Methyl Isothiocyanate ◽

Volatile Emission ◽

Brassica Crops ◽

Wide Range ◽

Promising Treatment

There is a need to develop new ways of protecting plants against aphid attack. Here, we investigated the effect of a plant defence activator, cis-jasmone (CJ), in a range of cultivars of Brassica napus, Brassica rapa and Brassica oleracea. Plants were sprayed with cis-jasmone or blank formulation and then tested with peach potato aphids (Myzus persicae Sulzer) (Hemiptera: Aphididae) and their parasitoid Diaeretiella rapae (M'Intosh) (Hymenoptera: Braconidae). CJ treated plants had significantly lower aphid settlement than control plants in a settlement bioassay. Conversely, in a foraging bioassay, D. rapae parasitoids spent a significantly longer time foraging on CJ treated plants. Our results reveal that CJ treatment makes plants less attractive to and less suitable for M. persicae but more attractive to D. rapae in a range of brassica cultivars. It is likely that these effects are due to changes in volatile emission indicating activation of defence and presence of conspecific competitors to aphids but presence of prey to parasitoids. Increases in volatile emission were found in CJ induced plants but varied with genotype. Among the synthetic volatile compounds that were induced in the headspace of CJ treated brassica cultivars, methyl isothiocyanate, methyl salicylate and cis-jasmone were most repellent to aphids. These results build on earlier studies in Arabidopsis and show that tritrophic interactions are influenced by CJ in a wide range of brassica germplasm. The implication is that CJ is a promising treatment that could be used in brassica crops as part of an integrated pest management system.