scholarly journals Septoria epidemics on wheat: combined use of visual assessment and PCR-based diagnostics to identify mechanisms of disease escape

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 421-424 ◽  
Author(s):  
B.A. Fraaije ◽  
D.J. Lovell ◽  
S. Baldwin
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Visual Assessment ◽  
Septoria Tritici ◽  
Stagonospora Nodorum ◽  
Disease Development ◽  
Crop Height ◽  
Primary Mechanism ◽  
Combined Use ◽  
Extent Of Disease

The effect of crop height on the epidemics of Septoria tritici and Stagonospora nodorum was investigated using visual assessment and PCR-based assays. Based on the results of our study, the primary mechanism of disease escape in tall crops is through a reduction of spore arrival. Real-time PCR is an important tool to quantify spore arrival and can, in combination with visual assessment, identify factors involved in the onset and extent of disease development.

scholarly journals Rhizoctonia solani AG2-1 causing root rot of wasabi (Eutrema japonica) in the UK

Plant Disease ◽  
2021 ◽  
Author(s):  
James Warwick Woodhall ◽  
EDER SOMOZA VALDEOLMILLOS ◽  
Kate Perkins ◽  
Ann Barnes ◽  
Toomo Misawa
Keyword(s):  
Rhizoctonia Solani ◽  
Real Time ◽  
Real Time Pcr ◽  
Visual Assessment ◽  
Causal Agent ◽  
Penicillin G ◽  
Pcr Assay ◽  
Poor Growth ◽  
Root Area ◽  
The Uk

In 2014, glasshouse-grown wasabi (Eutrema japonica) grown in a compost based media displayed symptoms of poor growth and wilting. Visual assessment of the roots showed that 25% of the symptomatic plants sampled had raised black lesions on the roots affecting between 5 and 20% of the total root area. To isolate the causal agent, affected material (approximately 5 mm3) was surface disinfested in sodium hypochlorite (2%) for 30 s, rinsed twice in sterile water and plated on to water agar medium amended with penicillin G (0.2 g/liter) and streptomycin sulfate (0.8 g/liter). Plates were incubated at 20ºC until fungal colonies were visible. After three days, colonies of Rhizoctonia solani were identified based on the presence of septate hyphae with right-angle branching, a pure culture was obtained through hyphal tip transfer onto a new plate of PDA. DNA was extracted from a 7-day old plate of the isolate (WAS1) as described previously (Woodhall et al., 2013). The AG of WAS1 was determined as AG2-1 using a subgroup specific real-time PCR assay (Budge et al., 2009b) and confirmed by DNA sequencing as described previously (Lekuona Gomez et al., 2015). The sequence was 100% identical (587/587bp) to a previously identified AG2-1 isolate 1971 (GenBank accession FJ435126) (Budge et al., (2009a). Pathogenicity of the isolate was confirmed by inoculating three healthy one-year-old wasabi plants grown in loam based compost (John Innes No.3) each with four 5 mm fully colonised PDA plugs of isolate WAS1 placed at approx. 40 mm depth in the soil. Four sterile PDA plugs were place in each of three control plants. All six plants were placed in a greenhouse at 21°C, 18h:6h light: dark and watered as required. After 21 days, multiple black root lesions typically 3-5mm in length were observed on the roots of all inoculated plants. No lesions were observed on the control plants. From three lesions per plant, isolations were attempted as described above. Rhizoctonia solani was recovered from all isolations and the resulting cultures all tested positive for AG2-1 using the real-time PCR assay. Isolations were attempted from the roots of healthy control plants but Rhizoctonia was not recovered. Here we demonstrate that R. solani AG2-1 is associated with root necrosis of Eutrema japonica. Rhizoctonia solani AG2-1 has been reported previously in various Brassica crops in the UK (Budge et al., 2009a) and on Matthiola incana (Lekuona Gómez et al., 2015). It has also been reported causing disease in potatoes and as widely present in UK field soils (Woodhall et al., 2013). Although R. solani AG1 and AG4 of R. solani have been reported to infect Eutrema japonica in Japan (Takeuchi et al., 2003; 2008), this is the first finding that identifies AG2-1 as the causal agent. The potential presence of AG2-1 in soil and/or as plant debris should be considered prior to planting susceptible hosts.

scholarly journals Combined use of real-time PCR and nested sequence-based typing in survey of humanLegionellainfection

2016 ◽  
Vol 144 (9) ◽  
pp. 2006-2010 ◽  
Author(s):  
T. QIN ◽  
H. ZHOU ◽  
H. REN ◽  
W. SHI ◽  
H. JIN ◽  
...  
Keyword(s):  
Real Time ◽  
Legionella Pneumophila ◽  
Real Time Pcr ◽  
Pcr Amplification ◽  
Lavage Fluid ◽  
Rrna Gene ◽  
Culture Methods ◽  
Combined Use ◽  
Antigen Tests ◽  
Nested Sequence

SUMMARYLegionnaires’ disease (LD) is a globally distributed systemic infectious disease. The burden of LD in many regions is still unclear, especially in Asian countries including China. A survey ofLegionellainfection using real-time PCR and nested sequence-based typing (SBT) was performed in two hospitals in Shanghai, China. A total of 265 bronchoalveolar lavage fluid (BALF) specimens were collected from hospital A between January 2012 and December 2013, and 359 sputum specimens were collected from hospital B throughout 2012. A total of 71 specimens were positive forLegionellaaccording to real-time PCR focusing on the 5S rRNA gene. Seventy of these specimens were identified asLegionella pneumophilaas a result of real-time PCR amplification of thedotA gene. Results of nested SBT revealed high genetic polymorphism in theseL. pneumophilaand ST1 was the predominant sequence type. These data revealed that the burden of LD in China is much greater than that recognized previously, and real-time PCR may be a suitable monitoring technology for LD in large sample surveys in regions lacking the economic and technical resources to perform other methods, such as urinary antigen tests and culture methods.

scholarly journals Combined use of real-time PCR and nested sequence-based typing in survey of human Legionella infection – ERRATUM

2016 ◽  
Vol 144 (12) ◽  
pp. 2688-2688
Author(s):  
T. QIN ◽  
H. ZHOU ◽  
H. REN ◽  
W. SHI ◽  
H. JIN ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Combined Use ◽  
Nested Sequence

scholarly journals Specific Detection of Viable Legionella Cells by Combined Use of Photoactivated Ethidium Monoazide and PCR/Real-Time PCR

2008 ◽  
Vol 75 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Bin Chang ◽  
Kanji Sugiyama ◽  
Toshitsugu Taguri ◽  
Junko Amemura-Maekawa ◽  
Fumiaki Kura ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Environmental Surveillance ◽  
Specific Detection ◽  
Pcr Assay ◽  
Ethidium Monoazide ◽  
Viable Cells ◽  
Combined Use ◽  
Significant Difference ◽  
Do So

ABSTRACT Legionella organisms are prevalent in manmade water systems and cause legionellosis in humans. A rapid detection method for viable Legionella cells combining ethidium monoazide (EMA) and PCR/real-time PCR was assessed. EMA could specifically intercalate and cleave the genomic DNA of heat- and chlorine-treated dead Legionella cells. The EMA-PCR assay clearly showed an amplified fragment specific for Legionella DNA from viable cells, but it could not do so for DNA from dead cells. The number of EMA-treated dead Legionella cells estimated by real-time PCR exhibited a 104- to 105-fold decrease compared to the number of dead Legionella cells without EMA treatment. Conversely, no significant difference in the numbers of EMA-treated and untreated viable Legionella cells was detected by the real-time PCR assay. The combined assay was also confirmed to be useful for specific detection of culturable Legionella cells from water samples obtained from spas. Therefore, the combined use of EMA and PCR/real-time PCR detects viable Legionella cells rapidly and specifically and may be useful in environmental surveillance for Legionella.

scholarly journals Accurate Assessment of Wheat and Triticale Cultivar Resistance to Septoria tritici and Stagonospora nodorum Infection by Biotin/Avidin ELISA

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1229-1234 ◽  
Author(s):  
Shimin Tian ◽  
Gerhard A. Wolf ◽  
Joachim Weinert
Keyword(s):  
Early Stage ◽  
Flag Leaf ◽  
Infected Plant ◽  
Visual Assessment ◽  
Field Trials ◽  
Septoria Tritici ◽  
Stagonospora Nodorum ◽  
Wheat Cultivars ◽  
Breeding Lines ◽  
Leaf Blotch

Specific and quantitative biotin/avidin-enzyme-linked immunosorbent assays (BA-ELISA) were evaluated for their ability to assess resistance of wheat and triticale cultivars to Septoria tritici (leaf blotch) and Stagonospora nodorum (leaf and glume blotch) in field trials. Using BA-ELISAs, the antigen amounts of S. tritici and of Stagonospora nodorum were measured in the flag leaf (F) and the first leaf below it (F-1) of five cultivars of triticale at Zadok's growth stage (GS) 75–80 and in 11 cultivars of wheat at GS 73–75 in 2001 and 2002. The presence of the pathogens was found to be specific to parts of the plants, cultivar, and plant species. Stagonospora nodorum was the dominant leaf blotch pathogen in triticale, while both Septoria tritici and Stagonospora nodorum occurred commonly in wheat. Close correlations were obtained between the pathogen amount measured by BA-ELISA and the percentage of necrotic leaf area in the tested cultivars. The BA-ELISA values for the tested triticale and wheat cultivars were ranked, and they correlated well with the susceptibility ratings given in the cultivar list recommended by Bundessortenamt (German Federal Office of Plant Variety), which is based on visual assessment of the leaf blotch complex caused by S. tritici and Stagonospora nodorum. The relative susceptibilities of individual wheat cultivars to both pathogens were similar. In conclusion, BA-ELISA provided for an accurate diagnosis and quantification of S. tritici and Stagonospora nodorum in infected plant tissue, and therefore can be used to assess resistance to these fungi in a disease complex in both early-stage breeding lines and field trials.

Feldvalidierung einer real-time PCR zum Nachweis von Mycoplasma hyopneumoniae in Nasentupfermaterial von lebenden Schweinen

2005 ◽  
Vol 147 (9) ◽  
pp. 373-379 ◽  
Author(s):  
F. Zeeh ◽  
P. Kuhnert ◽  
R. Miserez ◽  
M. G. Doherr ◽  
W. Zimmermann
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Mycoplasma Hyopneumoniae
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