Use of the vital stain FUN-1 indicates viability ofPhytophthora capsicipropagules and can be used to predict maximum zoospore production

Mycologia ◽  
2014 ◽  
Vol 106 (2) ◽  
pp. 362-367 ◽  
Author(s):  
Melanie L. Lewis Ivey ◽  
Sally A. Miller

2013 ◽  
Vol 162 (2) ◽  
pp. 69-80 ◽  
Author(s):  
Michael Pistininzi ◽  
Edward Weiss ◽  
Lauren Achtemeier ◽  
Chuanxue Hong


1993 ◽  
Vol 97 (12) ◽  
pp. 1495-1498 ◽  
Author(s):  
W.J. Botha
Keyword(s):  


Plant Disease ◽  
2011 ◽  
Vol 95 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Tugba Adiyaman ◽  
David A. Schisler ◽  
Patricia J. Slininger ◽  
Jennifer M. Sloan ◽  
Mark A. Jackson ◽  
...  

The microbiota of 84 different agricultural soils were transferred to separate samples of a γ irradiation-sterilized field soil enriched with potato periderm, and the resulting soils were assayed for biological suppressiveness to Phytophthora erythroseptica and their effect on zoospore production. The 13 most suppressive soil samples, which reduced zoospore production by 14 to 93% and disease severity on tubers by 6 to 21%, were used to isolate 279 organisms. Fourteen strains that reduce pink rot infections in preliminary tests were selected for further study. Six bacterial strains that reduced the severity of disease (P ≤ 0.05, Fischer's protected least significant difference) in subsequent tests were identified as Bacillus simplex (three strains), Pantoea agglomerans, Pseudomonas koreensis, and P. lini. Relative performance indices (RPIs) for biocontrol efficacy and for each of four kinetic parameters, including total colony-forming units (CFUmax), biomass production values (DWmax), cell production after 8 h (OD8), and time of recovery from oxygen depletion (DT) were calculated for each strain. Overall RPIEff,Kin values for each strain then were calculated using strain RPI values for both efficacy (RPIEff) and kinetics (RPIKin). Strains with the highest RPIEff,Kin possess the best biocontrol efficacy of the strains tested and liquid culture growth characteristics that suggest commercial development potential.







1969 ◽  
Vol 11 (4) ◽  
pp. 987-992 ◽  
Author(s):  
Carl C. Lindegren ◽  
Paraskevi M. Be Miller

Squashes of yeast cells grown in nutrient medium containing cobalt were observed by phase- and electron-microscopy. Co++ is a vital stain that is bound to structures inside the inner membrane of the mitochondria.



2018 ◽  
Vol 108 (12) ◽  
pp. 1412-1419 ◽  
Author(s):  
Jianqiang Miao ◽  
Yuandong Chi ◽  
Dong Lin ◽  
Brett M. Tyler ◽  
Xili Liu

Oxathiapiprolin is a novel fungicide that was recently registered in a number of countries to control plant-pathogenic oomycetes such as Phytophthora capsici. In our previous study, point mutations G770V and G839W in oxysterol binding protein-related protein 1 (ORP1) were detected in oxathiapiprolin-resistant P. capsici isolates (PcORP1). Here, we used the CRISPR/Cas9 system to verify the effects of these two point mutations on P. capsici phenotypes. Transformants containing heterozygous G770V and G839W mutations in PcORP1 showed high levels of oxathiapiprolin resistance. The G770V transformants showed otherwise similar phenotypes compared with the wild-type isolate BYA5, including sporangia and zoospore production, cyst germination, and pathogenicity. However, two independent transformants with heterozygous G839W mutations in PcORP1 could not produce sporangia. Three transformants with an unexpected point mutation in PcORP1 (ΔN837) showed high oxathiapiprolin resistance, and either similar or significantly reduced fitness compared with BYA5. The same deletion (ΔN837) was confirmed to confer oxathiapiprolin resistance in P. sojae by using CRISPR/Cas9. These homozygous P. sojae mutants also showed either similar or strongly reduced fitness compared with the wild-type parent isolate P6497. These results improve our understanding of oxathiapiprolin resistance in Phytophthora spp., and will be useful for the development of novel oxysterol-binding protein homolog inhibitor fungicides.



Mycologia ◽  
1988 ◽  
Vol 80 (2) ◽  
pp. 259-261 ◽  
Author(s):  
Z.-Q. An ◽  
J. W. Hendrix
Keyword(s):  


2020 ◽  
Vol 56 (No. 2) ◽  
pp. 74-82 ◽  
Author(s):  
Antonios Zambounis ◽  
Oksana Sytar ◽  
Dimitris Valasiadis ◽  
Zoe Hilioti

The phytopathogenic oomycetes of the genus Phytophthora cause devastating economic losses worldwide.<br />Naphthodianthrone compounds, present in plant extracts of buckwheat and Saint John’s wort act as photosensitiser<br />agents and exhibit antimicrobial activity against a number of pathogens. In this study, we investigated the potential<br />inhibitory effects of fagopyrin and hypericin on Phytophthora citrophthora (R.E. Sm. &amp; E.H. Sm.) Leonian 1906, the<br />main causal agent of rot diseases in deciduous trees. Fagopyrin had the highest inhibitory effect in the colony growth<br />at a concentration of 2% of a stock solution (3 mg/mL), inducing clubbed hyphae with round tips. Notably, hypericin<br />also inhibited the radial colony growth and increased the hyphal branching at the subapical region, while also promoting<br />the formation of enlarged cells with irregular shapes growing collectively as biofilm-like structures. In terms of the<br />mycelial dry weight, although both photosensitisers had considerable inhibitory effects, the fagopyrin treatment was<br />most effective. Leaf bioassays showed that under dark conditions the photosensitiser pre-treated zoospores formed a<br />dense, but aberrant, mycelial growth with penetration defects. In contrast, when the zoospore production was performed<br />under light conditions, the zoospores failed to cause necrotic lesions and penetration events implying that their<br />virulence was impaired. These findings shed light on the biological effects of fagopyrin and hypericin in the regulation<br />of the mycelial growth, morphology and pathogenicity of P. citrophthora.



Mycologia ◽  
1982 ◽  
Vol 74 (5) ◽  
pp. 820-825 ◽  
Author(s):  
A. J. Domnas ◽  
S. M. Fagan ◽  
S. Jaronski


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