scholarly journals Identification of Plasmodiophora brassicae Wor. isolate suppressing clubroot resistance in ‘Kilaxy’ F1 white cabbage

2014 ◽  
Vol 26 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Maria Wesołowska
Keyword(s):  
Plant Resistance ◽  
Plasmodiophora Brassicae ◽  
The Other ◽  
Infestation Level ◽  
Harvest Time ◽  
Clubroot Resistance ◽  
Resting Spore ◽  
Resistant Genes ◽  
Seed Inoculation ◽  
White Cabbage

ABSTRACT The purpose of this study was the evaluation of the pathogenicity of Plasmodiophora brassicae Wor. field isolates gathered from clubroot-infected white cabbage Brassica oleracea var. capitata L. f. alba plants grown in different areas of Poland. The virulence of seven isolates of the pathogen was tested. Breeding materials from white cabbage resistant and susceptible to P. brassicae were used as standard objects for isolate virulence screening. Cabbage seeds were infected by submerging them into a resting-spore suspension. A screening of plant resistance using a nine-degree scale based on root symptoms was carried out at the eight-week-old plantlets stage and at harvest time on afield infected by P. brassicae spores. Isolates from Pobiednik and Grębałów were defined as more virulent. The P isolate from Pobiednik also infested plants of the clubroot resistant ‘Kilaxy’ F1 cultivar, which indicated the suppression of clubroot resistance. Its reaction to the other six isolates confirmed the resistance of this cultivar. The susceptible HTM line was characterised by the highest infestation level. A difference in the susceptibility level was noticed between lines derived from those with resistant genes, i.e. Oregon123 and ‘Badger Shipper’. The Oregon123 line was less susceptible to the applied isolates. The effect of the isolates used for seed inoculation on the reaction of the dormant plants to the pathogen on the clubroot field was observed.

scholarly journals Isolate pathogenicity recognition of Plasmodiophora brassicae Wor. in different areas of Poland

2011 ◽  
Vol 23 (2) ◽  
pp. 165-174
Author(s):  
Maria Wesołowska
Keyword(s):  
Plasmodiophora Brassicae ◽  
Seedling Stage ◽  
Infestation Level ◽  
Test Results ◽  
Harvest Time ◽  
Resistance Level ◽  
Clubroot Resistance ◽  
Resistant Genes ◽  
White Cabbage ◽  
Adult Plants

Isolate pathogenicity recognition ofPlasmodiophora brassicaeWor. in different areas of PolandThe aim of the research conducted in 2007-2009 was the evaluation of the pathogenicity of eightPlasmodiophora brassicaeWor. isolates collected from clubroot-infested white cabbage growing in different areas of Poland. Breeding materials from white cabbage resistant and susceptible toP. brassicaewere used for this purpose. Cabbage seeds were infected by submerging them into a spore suspension. The screening of plant clubroot resistance using a nine-degree scale based on root symptoms was carried out at the eight-week-old seedling stage and at harvest time on a field infected byP. brassicaespores - called the ‘death field’. Differences in the pathogenicity of the collected isolates were determined. Isolates from Szczecin, Ostromęczyn, Krojczyn and Maszkienice were defined as the most virulent. Plants of the ‘Kilaxy’ F1white cabbage cultivar confirmed resistance to all isolates, while plants of the susceptible HTM line from the ‘Hitoma’ F1white cabbage cultivar were characterised by the highest infestation level. The evaluation of adult plants in the field with highP. brassicaespore contamination confirmed seedling test results. Different susceptibility was observed between sub-lines from the ‘Oregon 123’ and ‘Badger Shipper’ cultivars with resistant genes. ‘Oregon 123’ sub-lines were less susceptible to applied isolates than ‘Badger Shipper’ sub-lines at both the seedling stage and during the field test. A double-stage plant screening to pathogen reaction caused the elimination of the most susceptible plants at the seedling stage. Plants with a certain resistance level were planted in the ‘death field’.

ACADIE: A CLUBROOT RESISTANT CABBAGE CULTIVAR

1985 ◽  
Vol 65 (1) ◽  
pp. 233-235 ◽  
Author(s):  
M. S. CHIANG ◽  
R. CRÊTE
Keyword(s):  
Brassica Oleracea ◽  
Plasmodiophora Brassicae ◽  
The Other ◽  
Head Size ◽  
Research Station ◽  
Clubroot Resistance ◽  
Cultivar Description

The Acadie cabbage is resistant to races 1 and 6 (Williams 1966) or ECD16/31/30, 16/02/30 (Buczacki et al. 1975) of the clubroot pathogen, Plasmodiophora brassicae Wor. Attractiveness in color, firmness and uniformity of head size are the other main features of this cultivar. The Acadie cabbage cultivar was developed at the Agriculture Canada Research Station, Saint-Jean-sur-Richelieu, Québec.Key words: Brassica oleracea ssp. capitata, cabbage cultivar, cultivar description, clubroot resistance, crucifers

scholarly journals Greenhouse Evaluation of Clubroot Resistant-Brassica napus cv. Mendel and Its Efficacy Concerning Virulence and Soil Inoculum Levels of Plasmodiophora brassicae

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 151 ◽  
Author(s):  
Nazanin Zamani-Noor ◽  
Imke Krohne ◽  
Birger Koopmann
Keyword(s):  
Brassica Napus ◽  
Plasmodiophora Brassicae ◽  
Root Weight ◽  
Susceptible Cultivar ◽  
Clubroot Resistance ◽  
Soil Inoculum ◽  
Resting Spore ◽  
Greenhouse Evaluation ◽  
Major Resistance Gene ◽  
Resting Spores

Clubroot resistance of oilseed rape (OSR) cultivars frequently relies on a major resistance gene originating from cv. Mendel. The efficacy of this resistance was studied in greenhouse experiments using two Plasmodiophora brassicae isolates, which were either virulent (P1(+)) or avirulent (P1) on Mendel. Seeds of clubroot-susceptible cultivar Visby and clubroot-resistant cultivar Mendel were sown in soil mixtures inoculated with different concentrations of resting spores (101, 103, 105, and 107 resting spores/g soil). Clubroot severity, plant height, shoot and root weight as well as resting spore propagation were assessed for each isolate and cultivar separately at four dates after sowing. The OSR cultivars behaved significantly different in the measured parameters. The threshold of inoculum density to cause disease depended strongly on the virulence of the pathogen and susceptibility of the host plant. In Visby grown in soil infested with P1, clubroot symptoms and increases in root weight and the number of propagated resting spores occurred at inoculum levels of 101 resting spores and higher, whereas Mendel was not affected in soils under the three lowest inoculum densities. In contrast, the P1(+) isolate led to earlier and more severe symptoms, heavier galls, and a significantly higher number of new resting spores in both cultivars.

Screening of Brassica germplasm for resistance to Plasmodiophora brassicae pathotypes prevalent in Canada for broadening diversity in clubroot resistance

2012 ◽  
Vol 92 (3) ◽  
pp. 501-515 ◽  
Author(s):  
Muhammad Jakir Hasan ◽  
Stephen E. Strelkov ◽  
Ronald J. Howard ◽  
Habibur Rahman
Keyword(s):  
Brassica Rapa ◽  
Oilseed Rape ◽  
Specific Resistance ◽  
Plasmodiophora Brassicae ◽  
Diploid Species ◽  
The Other ◽  
Clubroot Disease ◽  
Clubroot Resistance ◽  
Resistant Cultivars ◽  
Spring Type

Hasan, M. J., Strelkov, S. E., Howard, R. J. and Rahman, H. 2012. Screening of Brassica germplasm for resistance to Plasmodiophora brassicae pathotypes prevalent in Canada for broadening diversity in clubroot resistance. Can. J. Plant Sci. 92: 501–515. Clubroot disease of crucifers, caused by Plasmodiophora brassicae, poses a threat to the Canadian canola industry, and the development of resistant cultivars is urgently needed. Germplasm resistant to local pathotype(s) is the prime requirement for breeding clubroot-resistant cultivars. The objective of this study was to identify Brassica germplasm possessing resistance to P. brassicae pathotypes prevalent in Alberta. Pathotype-specific resistance was identified in the diploid species Brassica rapa (AA) and B. oleracea (CC), and in the amphidiploid B. napus (AACC). Among B. rapa genotypes, turnip was the most resistant, followed by winter type and spring type oilseed rape. The rutabaga group of B. napus, on the other hand, was homogeneous for resistance to Canadian P. brassicae pathotypes. The diploid species B. nigra (BB) also showed pathotype-specific resistance. However, the two amphidiploids carrying the B. nigra genome, B. juncea (AABB) and B. carinata (BBCC) were completely susceptible to clubroot.

The fine structure of the cystosorus of Spongospora subterranea, the cause of powdery scab of potato

1985 ◽  
Vol 63 (12) ◽  
pp. 2278-2282 ◽  
Author(s):  
H. Lahert ◽  
J. A. Kavanagh
Keyword(s):  
Plasmodiophora Brassicae ◽  
Wall Layer ◽  
Powdery Scab ◽  
Multivesicular Bodies ◽  
Periplasmic Space ◽  
Spongospora Subterranea ◽  
Harvest Time ◽  
Resting Spore ◽  
Transmission Electron

Cystosori of Spongospora subterranea (Wallr.) Lagerh., with cysts at different stages in development, were found on the surface of a potato powdery scab lesion in situ at harvest time and are described using light and transmission electron microscopy. The resting cyst cytoplasm has a five-layered envelope separating it from periplasmic space and is contained within a wall consisting of three layers (W1, W2, and W3). Protuberances on the outer surface of the cysts are outgrowths of the outermost (W1) wall layer. The differentiation of a primary zoospore within each cyst is marked by a reorganisation of the cytoplasmic envelope, the appearance of multivesicular bodies in the cytoplasm, and a germ pore with a thickened W3 wall rim. The ultrastructure of the cysts is compared with the resting spore and encysted primary zoospore of Plasmodiophora brassicae.

The life history of Plasmodiophora brassicae Woron

1972 ◽  
Vol 180 (1058) ◽  
pp. 103-112 ◽  
Keyword(s):  
Life History ◽  
Root Hair ◽  
Plasmodiophora Brassicae ◽  
Root Hairs ◽  
Secondary Phase ◽  
Tissue Cultures ◽  
Resting Spore ◽  
Resting Spores ◽  
Seedling Roots ◽  
History Of

Resting spore germination and the root hair stages of the life history of Plasmodiophora brassicae were studied in stained preparations of infected Brassica rapa seedling roots. Naked protoplasts, usually possessing two unequal flagella, were released from resting spores through a small circular pore. They penetrated the root hairs of B. rapa and there developed into plasmodia which, after becoming multinucleate, cleaved to form zoosporangia con­taining incipient zoospores. Biflagellate zoospores were released from root hair zoosporangia and fused in pairs, although karyogamy did not occur. The resulting binucleate zoospores infected the cortical dells of B. rapa to form binucleate plasmodia, the earliest stages of the secondary phase of the life history. These findings are discussed in relation to previous studies on the life history of P. brassicae in Brassica plants and in Brassica tissue cultures, and a new complete life history, including nuclear fusion in the secondary plasmodium, is suggested for the organism.

scholarly journals THE EFFECTIVENESS OF IMMUNOLOGICAL EVALUATION OF RESISTANCE OF THE WHITE CABBAGE LINES TO PLASMODIOPHORA BRASSICAE WOR. AGAINST ARTIFICIAL INFECTION BACKGROUND

2018 ◽  
pp. 97-100
Author(s):  
A. A. Ushakov ◽  
L. L. Bondareva ◽  
I. A. Engalycheva
Keyword(s):  
Plasmodiophora Brassicae ◽  
Background Intensity ◽  
Federal State ◽  
Causative Organism ◽  
Atmospheric Conditions ◽  
Artificial Infection ◽  
Entire Area ◽  
Clubroot Disease ◽  
White Cabbage ◽  
The Impact

Clubroot disease (causative organism Plasmodiophora brassicae Wor.) is among the most economically important and harmful diseases of the cole crops, and the damage due to this disease may reach up to 50-75% of the yield and even 100% in epiphytotics years. Even resistant varieties become susceptible over the years, because of appearance of the new pathogen races and change of climatic conditions in the main growing areas of the crop. In this context the Laboratory of Plant Immunity and Protection, of Federal State Budgetary Scientific Institution “Federal Scientific Vegetable Center” implements continuous phytoimmunological evaluation of collection and selection specimens and also directional material rather than just annual monitoring of causative organism dissemination in order to find new resistance sources. For this purpose an artificial infection background is used: compost obtained from decomposed nodules on the cabbage roots affected by clubroot disease (infection load 105-106 spores/cm3). The resistance of white cabbage varieties was evaluated during the harvesting period using five-point score of the root system damage, which formed the basis for categorization into resistance groups. For the analysis of artificial background intensity and specimen ranking the individual plants of the white cabbage variety Slava 1305, which is a susceptibility standard, were randomly planted in the entire area of the infection background. The impact of atmospheric conditions in the study year on the results of phytopathological evaluation of cabbage selection specimens against the infection background is demonstrated. Under unfavorable conditions for pathogen development (2014) the most specimens (74%) were categorized as relatively resistant, while in favourable for pathogen year 2015 relatively resistant specimens comprised only 5% of the total number of studied specimens. Since the same specimen may show different level of resistance depending on the year conditions, the stability of character manifestation is the important criterion for identification of the resistance resources. Phytopathological evaluation aimed on selection of clubroot-resistant forms in the Moscow region should last for at least three years even with the use of infection background. Long-lasting evaluation showed that the strains No 234/15,140/14,216/17 exhibiting high resistance to clubroot against artificial infection background regardless of the year conditions are the most valuable for selection. The resistance of white cabbage selection varieties to clubroot disease was studied against the infection background.

scholarly journals Taxonomic revision of the genus Zygorhizidium: Zygorhizidiales and Zygophlyctidales ord. nov. (Chytridiomycetes, Chytridiomycota)

2020 ◽  
Vol 5 (1) ◽  
pp. 17-38 ◽  
Author(s):  
K. Seto ◽  
S. Van Den Wyngaert ◽  
Y. Degawa ◽  
M. Kagami
Keyword(s):  
Molecular Phylogeny ◽  
Host Specificity ◽  
Type Species ◽  
Taxonomic Revision ◽  
The Other ◽  
Ultrastructural Observation ◽  
Resting Spore ◽  
Distinct Genus ◽  
Current Classification

During the last decade, the classification system of chytrids has dramatically changed based on zoospore ultrastructure and molecular phylogeny. In contrast to well-studied saprotrophic chytrids, most parasitic chytrids have thus far been only morphologically described by light microscopy, hence they hold great potential for filling some of the existing gaps in the current classification of chytrids. The genus Zygorhizidium is characterized by an operculate zoosporangium and a resting spore formed as a result of sexual reproduction in which a male thallus and female thallus fuse via a conjugation tube. All described species of Zygorhizidium are parasites of algae and their taxonomic positions remain to be resolved. Here, we examined morphology, zoospore ultrastructure, host specificity, and molecular phylogeny of seven cultures of Zygorhizidium spp. Based on thallus morphology and host specificity, one culture was identified as Z. willei parasitic on zygnematophycean green algae, whereas the others were identified as parasites of diatoms, Z. asterionellae on Asterionella, Z. melosirae on Aulacoseira, and Z. planktonicum on Ulnaria (formerly Synedra). According to phylogenetic analysis, Zygorhizidium was separated into two distinct order-level novel lineages; one lineage was composed singly of Z. willei, which is the type species of the genus, and the other included the three species of diatom parasites. Zoospore ultrastructural observation revealed that the two lineages can be distinguished from each other and both possess unique characters among the known orders within the Chytridiomycetes. Based on these results, we accommodate the three diatom parasites, Z. asterionellae, Z. melosirae, and Z. planktonicum in the distinct genus Zygophlyctis, and propose two new orders: Zygorhizidiales and Zygophlyctidales.

Sign in / Sign up

Export Citation Format

Share Document