Some Conditions Governing Zoospore Production in Axenic Cultures of Phytophthora cinnamomi Rands

1979 ◽  
Vol 27 (2) ◽  
pp. 103 ◽  
Author(s):  
P Byrt ◽  
BR Grant
Keyword(s):  
Plant Pathogen ◽  
Phytophthora Cinnamomi ◽  
Zoospore Production ◽  
Biochemical Studies ◽  
Axenic Cultures

A method for the production of zoospores from the plant pathogen Phytophthora cinnamomi is described. The use of siliconized cellulose pads as a hyphal support, which in turn allows shake- grown mycelia to be used, results in the production of zoospores in concentrations of 107-108/litre. It allows one person to produce the equivalent of 1-10 mg of zoospore protein per batch, which is sufficient for a variety of biochemical studies.

scholarly journals Effects of Gypsum on Zoospores and Sporangia of Phytophthora cinnamomi in Field Soil

Plant Disease ◽  
2000 ◽  
Vol 84 (6) ◽  
pp. 617-621 ◽  
Author(s):  
B. J. Messenger ◽  
J. A. Menge ◽  
E. Pond
Keyword(s):  
Calcium Sulfate ◽  
Phytophthora Cinnamomi ◽  
Calcium Nitrate ◽  
Passive Movement ◽  
Field Soil ◽  
Soil Extracts ◽  
Zoospore Production ◽  
Colony Forming Units ◽  
Amended Soil

Sporangial production of Phytophthora cinnamomi buried in gypsum-amended avocado soil for 2 days was reduced by as much as 74% in greenhouse trials. P. cinnamomi sporangial volume was reduced an average of 64% in gypsum-amended soil. Soil extracts from gypsum-amended soil reduced in vitro sporangial production and volume. Irrigation with gypsum solutions of buried mycelium in unamended soil also reduced sporangial production and volume. Zoospore production and colony-forming units of P. cinnamomi were reduced in soil amended with calcium sulfate, calcium nitrate, or calcium carbonate. Zoospore encystment or passive movement through soil was not significantly affected by gypsum soil amendments.

A light and electron microscope study of the interaction of soil bacteria with Phytophthora cinnamomi Rands

1977 ◽  
Vol 23 (11) ◽  
pp. 1518-1525 ◽  
Author(s):  
N. Malajczuk ◽  
H. J. Nesbitt ◽  
A. R. Glenn
Keyword(s):  
Soil Bacteria ◽  
Phytophthora Cinnamomi ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Microbial Association ◽  
Reproductive Structures ◽  
Streptomyces Spp ◽  
Lysis Inhibition ◽  
Zoospore Production

Light- and electron-microscopic examination showed that bacteria became associated with the hyphae and asexual reproductive structures of P. cinnamomi in soil. In suppressive soils this association appears to be correlated with hyphal lysis, inhibition of zoospore production, and sporangial breakdown. One notable feature of the microbial association between P. cinnamomi and soil bacteria is the formation of extensive slime material. Many of the bacteria isolated from the fungal hyphosphere display antagonism to the growth of P. cinnamomi in vitro. The bacteria are morphologically varied and include Pseudomonas, Bacillus, and Streptomyces spp. These observations suggest that the appropriate manipulation of the antagonistic bacteria may provide a means of biological control of P. cinnamomi.

Phylogeography of the wide‐host range panglobal plant pathogen Phytophthora cinnamomi

2021 ◽  
Author(s):  
Shankar K. Shakya ◽  
Niklaus J. Grünwald ◽  
Valerie J. Fieland ◽  
Brian J. Knaus ◽  
Jerry E. Weiland ◽  
...  
Keyword(s):  
Host Range ◽  
Plant Pathogen ◽  
Phytophthora Cinnamomi ◽  
Wide Host Range

scholarly journals Flower visitation by honey possums (Tarsipes rostratus) in a coastal banksia heathland infested with the plant pathogen Phytophthora cinnamomi

2013 ◽  
Vol 35 (2) ◽  
pp. 166 ◽  
Author(s):  
Shannon J. Dundas ◽  
Patricia A. Fleming ◽  
Giles E. St J. Hardy
Keyword(s):  
Plant Pathogen ◽  
Conservation Management ◽  
Phytophthora Cinnamomi ◽  
Pollen Grains ◽  
Floristic Diversity ◽  
Vegetation Composition ◽  
Flower Visitation ◽  
South West ◽  
Potential Impact ◽  
A Site

The honey possum (Tarsipes rostratus) is a tiny (7–10 g) obligate nectarivore endemic to south-west Western Australia that relies on high floristic diversity for year-round nectar and pollen resources. We investigated flower visitation by honey possums at a site in the presence of the plant pathogen Phytophthora cinnamomi by sampling pollen on the head of captured and radio-tracked individuals. The aim of the study was to identify plant species that were visited and to compare these with known susceptibility to Phytophthora to assess the potential impact of further spread of the pathogen on honey possums. Nine plant taxa were regularly identified from pollen on honey possums, including four Banksia species. Six of the nine plant taxa identified (Banksia plumosa, Adenanthos cuneatus, Calothamnus gracilis, B. brunnea, B. nutans, B. tenuis) were most frequently visited by honey possums, each making up >20% of pollen grains for at least one season. Five of the nine plant taxa are known to be susceptible to Phytophthora, which substantially changes vegetation composition in its wake. The inevitable spread of Phytophthora is postulated to result in the localised loss of resources for honey possums and is a concern for on-going conservation management.

scholarly journals Draft genomes of two Australian strains of the plant pathogen, Phytophthora cinnamomi

F1000Research ◽  
2018 ◽  
Vol 6 ◽  
pp. 1972 ◽  
Author(s):  
Amy L. Longmuir ◽  
Peter L. Beech ◽  
Mark F. Richardson
Keyword(s):  
Plant Pathogen ◽  
Reference Genome ◽  
Phytophthora Cinnamomi ◽  
Gene Prediction ◽  
Single Copy ◽  
Draft Assembly ◽  
Protein Encoding ◽  
Pathogen Control ◽  
Genome Assemblies ◽  
Encoding Genes

Background: The oomycete plant pathogen, Phytophthora cinnamomi, is responsible for the destruction of thousands of species of native Australian plants, as well as several crops, such as avocado and macadamia, and has one of the widest host-plant ranges of the Phytophthora genus. The current reference genome of P. cinnamomi is based on an atypical strain and has large gaps in its assembly. To further studies of the pathogenicity of this species, especially in Australia, robust genome assemblies of more typical strains are required. Here we report the genome sequencing, draft assembly, and preliminary annotation of two geographically separated Australian strains of P. cinnamomi. Findings:  Some 308 million raw reads were generated for the two strains, DU054 and WA94.26. Independent genome assembly produced final genome sequences of 62.8 Mb (in 14,268 scaffolds) and 68.1 Mb (in 10,084 scaffolds), which are comparable in size and contiguity to other Phytophthora genomes. Gene prediction yielded > 22,000 predicted protein-encoding genes within each genome, while BUSCO assessment showed 94.4% and 91.5% of the stramenopile single-copy orthologs to be present in the assembled genomes, respectively. Conclusions: The assembled genomes of two geographically distant isolates of Phytophthora cinnamomi will provide a valuable resource for further comparative analyses and evolutionary studies of this destructive pathogen, and further annotation of the presented genomes may yield possible targets for novel pathogen control methods.

Factors influencing zoospore production by Phytophthora cinnamomi in axenic cultui

1980 ◽  
Vol 58 (19) ◽  
pp. 2117-2122 ◽  
Author(s):  
Calvin L. Schoulties ◽  
Kenneth F. Baker ◽  
Carol Sabersky-Lehmann
Keyword(s):  
Salt Solution ◽  
Phytophthora Cinnamomi ◽  
Mineral Salt ◽  
Distilled Water ◽  
Sporulation Medium ◽  
Uniform Size ◽  
Factors Influencing ◽  
Zoospore Release ◽  
Zoospore Production

Factors and procedures found to increase the quantity and consistency of axenic zoospore production in a selected isolate of Phytophthora cinnamomi were (i) the use of single-zoospore cultures of uniform size that were between 48 and 72 h old; (ii) thorough washing of mycelial mats at the time of sporangium induction to remove nutrients; (iii) agitation of the sporulation medium (mineral salt solution) 24 h after the initial induction; (iv) standardization of the volume of the sporulation medium; (v) adequate removal of the sporulation medium and replacement with distilled water before triggering zoospore release; and (vi) placement of colonies that had been induced to sporulate under light. The addition of a purified sporangium stimulatory substance to mycelial mats which had been induced to sporulate enabled the fungus to sporulate under conditions which normally suppressed sporulation in vitro. In the presence of this stimulatory substance, the fungus sporulated prolifically in darkness and with limited quantities of added nutrients. Other isolates of P. cinnamomi responded in a similar manner to many of these factors and procedures.

scholarly journals Draft genomes of two Australian strains of the plant pathogen, Phytophthora cinnamomi

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1972 ◽  
Author(s):  
Amy L. Longmuir ◽  
Peter L. Beech ◽  
Mark F. Richardson
Keyword(s):  
Plant Pathogen ◽  
Phytophthora Cinnamomi ◽  
Gene Prediction ◽  
Single Copy ◽  
Control Methods ◽  
Draft Assembly ◽  
Protein Encoding ◽  
Evolutionary Studies ◽  
Pathogen Control ◽  
Encoding Genes

Background: The oomycete plant pathogen, Phytophthora cinnamomi, is responsible for the destruction of thousands of species of native Australian plants, as well as several crops, such as avocado and macadamia, and has one of the widest host-plant ranges of the Phytophthora genus. The currently available genome of P. cinnamomi is based on an atypical strain and has large gaps in its assembly. To further studies of the pathogenicity of this species, especially in Australia, more robust assemblies of the genomes of more typical strains are required. Here we report the genome sequencing, draft assembly, and preliminary annotation of two geographically separated Australian strains of P. cinnamomi. Findings:  Some 308 million raw reads were generated for the two strains. Independent genome assembly produced final genomes of 62.8 Mb (in 14,268 scaffolds) and 68.1 Mb (in 10,084 scaffolds), which are comparable in size and contiguity to other Phytophthora genomes. Gene prediction yielded > 22,000 predicted protein-encoding genes within each genome, while BUSCO assessment showed 82.5% and 81.8% of the eukaryote universal single-copy orthologs to be present in the assembled genomes, respectively. Conclusions: The assembled genomes of two geographically distant isolates of Phytophthora cinnamomi will provide a valuable resource for further comparative analysis and evolutionary studies of this destructive pathogen, and further annotation of the presented genomes may yield possible targets for novel pathogen control methods.

scholarly journals Characterization and Evolutionary Analysis of a Large Polygalacturonase Gene Family in the Oomycete Plant Pathogen Phytophthora cinnamomi

2002 ◽  
Vol 15 (9) ◽  
pp. 907-921 ◽  
Author(s):  
Arvid Götesson ◽  
Jerry S. Marshall ◽  
David A. Jones ◽  
Adrienne R. Hardham
Keyword(s):  
Gene Family ◽  
Plant Pathogen ◽  
Fungal Pathogens ◽  
Plant Cell Wall ◽  
Genomic Library ◽  
Phytophthora Cinnamomi ◽  
Reticulate Evolution ◽  
Evolutionary Analysis ◽  
Degenerate Primers ◽  
Terminal Structure

Polygalacturonases (PGs) are secreted by fungal pathogens during saprophytic and parasitic growth, and their degradation of pectin in the plant cell wall is believed to play a major role in tissue invasion and maceration. In this study, PG activity was demonstrated in culture filtrates of the oo-mycete plant pathogen, Phytophthora cinnamomi. A P. cinnamomi pg gene fragment amplified using degenerate primers based on conserved regions in fungal and plant PGs was used to isolate 17 complete P. cinnamomi pg genes and pseudogenes from a genomic library and partial sequence for another two genes. Gel blotting of genomic DNA indicated that there may be even more pg genes in the P. cinnamomi genome. P. cinnamomi pg gene sequences were expressed in PG-deficient yeast and found to confer PG activity, thereby confirming their functional identity. The predicted mature P. cinnamomi PGs fall into subgroups that exhibit large differences in the extent of N-glycosylation, isoelectric points, and N- and C-terminal structure. Evidence for birth-and-death and reticulate evolution in the P. cinnamomi pg gene family was obtained, and some codons for surface exposed residues in the P. cinnamomi PGs were shown to have been subject to diversifying selection. Contrary to accepted phylogenies for other proteins, phylogenetic analysis of the P. cinnamomi PGs revealed a closer relationship with PGs from true fungi than with those from plants.

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