Profile of the in vitro secretome of the barley net blotch fungus, Pyrenophora teres f. teres

SUMMARYAn experiment at Rothamsted in 1985–89 and another at Whaddon in 1986 studied the effects of incorporating straw on diseases of winter barley. Net blotch (Pyrenophora teres) and leaf blotch (Rhynchosporium secalis) were initially less severe where straw was burnt or incorporated by ploughing than where cultivations only partially buried it. However, by summer both diseases were usually more severe where straw had been burnt than where it had been incorporated. At Whaddon, eyespot (Pseudocercosporella herpotrichoides) tended to be less severe in tine-cultivated plots where straw was incorporated than where it was burnt, but at Rothamsted, where the straw treatments were confounded with cultivations, there was no consistent effect. The disease was usually more severe where straw was incorporated by ploughing than where it was incorporated using other methods. In contrast, the severity of take-all was generally decreased by ploughing. Seedlings usually grew better where straw had been burnt rather than incorporated and grain yields were often larger. However, yields at Rothamsted in 1987 were unusually, and inexplicably, smaller after burning the straw so that the 5-year mean yields showed no significant differences between treatments.

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Investigating in vitro mating preference between or within the two forms of Pyrenophora teres and its hybrids

Phytopathology ◽

10.1094/phyto-02-21-0058-r ◽

2021 ◽

Author(s):

Buddhika Amarasinghe Dahanayaka ◽

Niloofar Vaghefi ◽

Lisle Snyman ◽

Martin Anke

Keyword(s):

Mating Preference ◽

Pyrenophora Teres ◽

Net Blotch ◽

Yield Losses ◽

Significant Yield ◽

Novel Concept ◽

Ascospore Production

Net blotch diseases result in significant yield losses to barley industries worldwide. They occur as net-form and spot-form net blotch caused by P. teres f. teres (Ptt) and P. teres f. maculata (Ptm), respectively. Hybridisation between the forms was proposed to be rare, but recent identifications of field hybrids has renewed interest in the frequency and mechanisms underlying hybridisation. This study investigates the mating preference of Ptt, Ptm and laboratory-produced hybrids in vitro, using 24 different isolates and four different experimental setups. Two crosses in our study produced ascospores during two intervals separated by a 32-35 day period of no ascospore production. For these crosses Ptt isolates mated with isolates of the same form during the early ascospore production interval and produced hybrids during the later interval. Ptm isolates did not mate with isolates of the same form, instead hybridised with Ptt isolates. Analyses based on DArTseq™ markers confirmed that laboratory-produced hybrids, when given the choice to mate with both Ptt and Ptm, mated with Ptt isolates. These results unravel a novel concept that Ptt seems to have a greater reproduction robustness than Ptm, which could lead to increased prevalence of hybrid incidences in vivo.

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Virulence of Icelandic Pyrenophora teres f. teres populations and resistance of Icelandic spring barley lines

Journal of Plant Pathology ◽

10.1007/s42161-021-00972-5 ◽

2021 ◽

Author(s):

Fluturë Novakazi ◽

Magnus Göransson ◽

Tryggvi Sturla Stefánsson ◽

Marjo Hokka ◽

Marja Jalli ◽

...

Keyword(s):

Spring Barley ◽

Pyrenophora Teres ◽

Net Blotch ◽

High Susceptibility ◽

Pathogen Population ◽

Single Spore ◽

Barley Cultivars ◽

Principle Coordinate Analysis ◽

High Level ◽

Barley Net Blotch

AbstractThe causal agent of the barley net blotch disease, Pyrenophora teres, is known for its high level of diversity due to sexual reproduction. Different pathotypes, defined by a virulence combination, even within the same fields are frequently found and virulence between locations can vary considerably. Evaluation of virulence patterns of a pathogen population is essential for breeding resistant cultivars suitable for specific locations. To identify virulence patterns in Icelandic Pyrenophora teres f. teres (Ptt) isolates, twenty single spore isolates of Ptt were collected from seven locations in Iceland and analysed with AFLP markers. Principle Coordinate Analysis (PCoA) revealed Icelandic Ptt isolates clustering away from reference isolates from Austria, Finland, Sweden, Switzerland, UK, and USA. Hierarchical clustering grouped the Icelandic isolates into three distinct groups. Furthermore, the virulence of these twenty isolates was tested on 16 barley differential lines and revealed high variation in their virulence. Twenty-one barley cultivars commonly used in Iceland showed high susceptibility towards inoculation with Icelandic Ptt isolates.

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Study of the influence of barley varieties with different resistance to barley net blotch on the change in the structure of the hemibiotrophic pathogen population by morphological and cultural characteristics and virulence

BIO Web of Conferences ◽

10.1051/bioconf/20202100030 ◽

2020 ◽

Vol 21 ◽

pp. 00030

Author(s):

Galina Volkova ◽

Yana Yakhnik ◽

Alena Smirnova ◽

Egor Klychnikov

Keyword(s):

Growth Rate ◽

Specific Resistance ◽

Pyrenophora Teres ◽

Net Blotch ◽

Cultural Characteristics ◽

Pathogen Population ◽

Selection For ◽

High Level ◽

Barley Net Blotch

The study is devoted to the analysis of the correlation of morphological and cultural characteristics and virulence of Pyrenophora teres Drechs. isolates, and various resistance to the pathogen of barley varieties (Versal, Kubagro-1, Romance). The main morphological types of colonies of the fungus isolates obtained from the barley varieties with different resistance were determined. It was found that the higher degree of resistance of the variety, the faster growth rate of colonies, the intensity of sporulation and heterogeneity of the population on the basis of virulence increase. The most common races were detected in the populations of P. teres isolated from different varieties of barley. We found that the selection for the virulence of the pathogen population in Versal variety with a high level of non-specific resistance was carried out with a wider spectrum of diversity.

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Proteinaceous Metabolites from Pyrenophora teres Contribute to Symptom Development of Barley Net Blotch

Phytopathology ◽

10.1094/phyto-97-8-0907 ◽

2007 ◽

Vol 97 (8) ◽

pp. 907-915 ◽

Cited By ~ 29

Author(s):

Abolfazl Sarpeleh ◽

Hugh Wallwork ◽

David E. A. Catcheside ◽

Max E. Tate ◽

Amanda J. Able

Keyword(s):

Low Molecular Weight ◽

Pyrenophora Teres ◽

Susceptible Cultivar ◽

Net Blotch ◽

Symptom Development ◽

Hordeum Vulgare L ◽

Barley Cultivars ◽

Low Molecular Weight Compounds ◽

Necrotic Spots ◽

Barley Net Blotch

Pyrenophora teres, the causal agent of net blotch of barley (Hordeum vulgare L.), induces a combination of necrosis and extensive chlorosis in susceptible barley cultivars. Cell-free filtrates from both net and spot forms of P. teres; P. teres f. sp. teres, and P. teres f. sp. maculata were found to contain phytotoxic low molecular weight compounds (LMWCs) and proteinaceous metabolites which appear to be responsible for different components of the symptoms induced by the two forms of the pathogen in a susceptible cultivar of barley (cv. Sloop). Proteins induced only brown necrotic spots or lesions similar to those induced by the pathogens 72 h after inoculation. In contrast, LMWCs induced general chlorosis seen 240 h after inoculation but not the localized necrosis. Neither hydrolyzed or heat- or protease-treated proteinaceous metabolites induced the symptoms. This is the first report of the involvement of proteins produced by P. teres in symptom development during net blotch disease of barley.

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