scholarly journals Hybrids within the genus Brassica and chemical mutants of Brassica napus – the potential sources of resistance to clubroot (Plasmodiophora brassicae)

2015 ◽  
Vol 55 (1) ◽  
1998 ◽  
Vol 130 (2) ◽  
pp. 241-242 ◽  
Author(s):  
Palaniswamy Pachagounder ◽  
Robert J. Lamb

The crucifer flea beetle, Phyllotreta cruciferae (Goeze), feeds primarily on plants in the Brassicaceae (Cruciferae) (Feeny et al. 1970). Introduced from Europe, it is now a widespread pest of canola, Brassica napus L. and Brassica rapa L., in North America (Lamb and Turnock 1982; Weiss et al. 1991). Before canola occupied so much crop land in western Canada, flea beetles were present and presumably fed mostly on wild crucifers. These native and weedy crucifers are potential sources of resistance genes that might be transferred to canola. We examine feeding preferences of flea beetles among nine wild crucifers (Table 1) to determine which, if any, are avoided. The suitability of these plants has already been examined for another crucifer-feeding chrysomelid, the red turnip beetle, Entomoscelis americana Brown (Gerber and Obadofin 1981; Gerber 1984), and the feeding responses of the beetles are compared.


2021 ◽  
Vol 12 ◽  
Author(s):  
Piotr M. Kopec ◽  
Katarzyna Mikolajczyk ◽  
Ewa Jajor ◽  
Agnieszka Perek ◽  
Joanna Nowakowska ◽  
...  

Clubroot, caused by Plasmodiophora brassicae infection, is a disease of growing importance in cruciferous crops, including oilseed rape (Brassica napus). The affected plants exhibit prominent galling of the roots that impairs their capacity for water and nutrient uptake, which leads to growth retardation, wilting, premature ripening, or death. Due to the scarcity of effective means of protection against the pathogen, breeding of resistant varieties remains a crucial component of disease control measures. The key aspect of the breeding process is the identification of genetic factors associated with variable response to the pathogen exposure. Although numerous clubroot resistance loci have been described in Brassica crops, continuous updates on the sources of resistance are necessary. Many of the resistance genes are pathotype-specific, moreover, resistance breakdowns have been reported. In this study, we characterize the clubroot resistance locus in the winter oilseed rape cultivar “Tosca.” In a series of greenhouse experiments, we evaluate the disease severity of P. brassicae-challenged “Tosca”-derived population of doubled haploids, which we genotype with Brassica 60 K array and a selection of SSR/SCAR markers. We then construct a genetic map and narrow down the resistance locus to the 0.4 cM fragment on the A03 chromosome, corresponding to the region previously described as Crr3. Using Oxford Nanopore long-read genome resequencing and RNA-seq we review the composition of the locus and describe a duplication of TIR-NBS-LRR gene. Further, we explore the transcriptomic differences of the local genes between the clubroot resistant and susceptible, inoculated and control DH lines. We conclude that the duplicated TNL gene is a promising candidate for the resistance factor. This study provides valuable resources for clubroot resistance breeding programs and lays a foundation for further functional studies on clubroot resistance.


2019 ◽  
Author(s):  
Abdulsalam Dakouri ◽  
Mebarek Lamara ◽  
Md. Masud Karim ◽  
Jinghe Wang ◽  
Qilin Chen ◽  
...  

Abstract Background Clubroot of canola ( Brassica napus ), caused by the obligate pathogen Plasmodiophora brassicae Woronin, is a major disease worldwide. Genetic resistance remains the best strategy to manage this disease. The objective of the study was to identify and map new sources of resistance to clubroot in B. napus using genome-wide association mapping. The reaction of a collection of 177 accessions to four highly virulent pathotypes of P. brassicae was assessed. These pathotypes were selected because they were most recently identified and showed different virulence patterns on the Canadian clubroot differential (CCD) lines. The collection was then genotyped using genotyping by sequencing (GBS) method. Multi-locus mixed linear model (MMLM) was used to perform the association analysis. Results The majority of accessions were highly susceptible (70 –100 DSI), while few individual accessions showed strong resistance (0–20 DSI) to 5X (2 accessions), 2B (7 accessions), 3A (8 accessions) and 3D (15 accessions). In total, 301,753 SNPs were mapped to 19 chromosomes. Population structure analysis indicated that the 177 accessions belong to two major populations. SNPs were associated with resistance to each pathotype using MLMM. In total, 23 significant SNP loci were identified, with 14 SNPs mapped to the A-genome and 9 to the C-genome. The SNPs were associated with resistance to pathotypes 5X (4 SNPs), 2B (9), 3A (5) and 3D (5). A blast search of 2 Mb upstream and downstream identified 61 disease resistance genes, of which 24 belonged to TIR-NBS-LRR proteins and 20 belonged to CC-NBS-LRR proteins. The distance between a SNP locus and the nearest resistance genes ranged from 0.11–1.66 Mb. This indicated that NBS-LRR gene family might have an important role in clubroot resistance in B. napus . Conclusion The resistant B. napus lines and the SNP markers identified in this study can be used for breeding for resistance to clubroot and contribute to understanding the genetic mechanism of resistance to clubroot.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdulsalam Dakouri ◽  
Mebarek Lamara ◽  
Md. Masud Karim ◽  
Jinghe Wang ◽  
Qilin Chen ◽  
...  

AbstractGenetic resistance is a successful strategy for management of clubroot (Plasmodiophora brassicae) of brassica crops, but resistance can break down quickly. Identification of novel sources of resistance is especially important when new pathotypes arise. In the current study, the reaction of 177 accessions of Brassica napus to four new, virulent pathotypes of P. brassicae was assessed. Each accession was genotyped using genotyping by sequencing to identify and map novel sources of clubroot resistance using mixed linear model (MLM) analysis. The majority of accessions were highly susceptible (70–100 DSI), but a few accessions exhibited strong resistance (0–20 DSI) to pathotypes 5X (21 accessions), 3A (8), 2B (7), and 3D (15), based on the Canadian Clubroot Differential system. In total, 301,753 SNPs were mapped to 19 chromosomes. Population structure analysis indicated that the 177 accessions belong to seven major populations. SNPs were associated with resistance to each pathotype using MLM. In total, 13 important SNP loci were identified, with 9 SNPs mapped to the A-genome and 4 to the C-genome. The SNPs were associated with resistance to pathotypes 5X (2 SNPs), 3A (4), 2B (5) and 3D (6). A Blast search of 1.6 Mb upstream and downstream from each SNP identified 13 disease-resistance genes or domains. The distance between a SNP locus and the nearest resistance gene ranged from 0.04 to 0.74 Mb. The resistant lines and SNP markers identified in this study can be used to breed for resistance to the most prevalent new pathotypes of P. brassicae in Canada.


2021 ◽  
Author(s):  
C. S. Karandeni Dewage ◽  
A. Qi ◽  
H. U. Stotz ◽  
Y. J. Huang ◽  
B. D. L. Fitt

2015 ◽  
Vol 65 (3) ◽  
pp. 435-440 ◽  
Author(s):  
H. Zhang ◽  
J. Feng ◽  
S.-F. Hwang ◽  
S. E. Strelkov ◽  
I. Falak ◽  
...  

PLoS ONE ◽  
2017 ◽  
Vol 12 (10) ◽  
pp. e0185907 ◽  
Author(s):  
Ying Zhao ◽  
Zhixiao Gao ◽  
Binnian Tian ◽  
Kai Bi ◽  
Tao Chen ◽  
...  

2016 ◽  
Vol 145 (3) ◽  
pp. 517-529 ◽  
Author(s):  
Stephen E. Strelkov ◽  
Sheau-Fang Hwang ◽  
Victor P. Manolii ◽  
Tiesen Cao ◽  
David Feindel

2020 ◽  
Vol 47 (1) ◽  
pp. 9-16
Author(s):  
K.D. Chamberlin ◽  
J.J. Baldessari ◽  
E.M.C. Mamani ◽  
M.V. Moreno

ABSTRACT Cultivated peanut, the third most important oilseed in the world, is consistently threatened by various diseases and pests. Sclerotinia minor Jagger (S. minor), the causal agent of Sclerotinia blight, is a major threat to peanut production in many countries and can reduce yield by up to 50% in severely infested fields. Host plant resistance will provide the most effective solution to managing Sclerotinia blight, but limited sources of resistance to the disease are available for use in breeding programs. Peanut germplasm collections are available for exploration and identification of new sources of resistance, but traditionally the process is lengthy, requiring years of field testing before those potential sources can be identified. Molecular markers associated with phenotypic traits can speed up the screening of germplasm accessions. The objective of this study was to genotype the peanut core collection of the Instituto Nacional de Tecnología Agropecuaria (INTA) Manfredi, Argentina, with a molecular marker associated with Sclerotinia blight resistance. One hundred and fifty-four (154) accessions from the collection were available and genotyped using the Simple Sequence Repeat (SSR) marker. Accessions from each botanical variety type represented in the core collection were identified as new potential sources of resistance and targeted for further evaluation in field tests for Sclerotinia blight resistance.


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