scholarly journals Changes in the population of Blumeria graminis f.sp. hordei in the Czech Republic from 2009 to 2010

2012 ◽  
Vol 47 (No. 2) ◽  
pp. 43-51 ◽  
Author(s):  
A. Dreiseitl
Keyword(s):  
Czech Republic ◽  
Powdery Mildew ◽  
Spring Barley ◽  
Blumeria Graminis ◽  
The Czech Republic ◽  
Barley Cultivars ◽  
Wide Range ◽  
Pathogen Populations

Virulences to powdery mildew resistances in barley cultivars mostly carrying unknown resistances were determined in 2009 and 2010. Random spore samples of the airborne pathogen populations originating from winter and spring barley fields were obtained by means of a mobile version of a jet spore sampler by travelling across theCzech Republic. In total 301 isolates were studied, 55 differentials carrying mostly unknown resistances were used and 80 pathotypes were found, of which 26 representing 73.1% of isolates were detected in both years. Virulence frequencies showed a wide range from 0% to 100%. Complexity of the 2010 population slightly increased, mostly due to increasing frequencies of virulence to new resistances, whereas the complexity of virulences to resistances in most other differentials decreased. Pathotype 00027 was the most abundant (10.0%). Diversity of the 2010 population  considerably increased due to changes in virulence frequencies.

scholarly journals Virulence frequency to powdery mildew resistances in winter barley cultivars

2009 ◽  
Vol 44 (No. 4) ◽  
pp. 160-166 ◽  
Author(s):  
A. Dreiseitl
Keyword(s):  
Czech Republic ◽  
Powdery Mildew ◽  
Spring Barley ◽  
Winter Barley ◽  
The Czech Republic ◽  
Barley Cultivars ◽  
Random Samples ◽  
Wide Range ◽  
The Given ◽  
Lower Population

Virulence frequencies to powdery mildew resistances in winter barley cultivars mostly registered in the Czech Republic were studied in 2007 and 2008. Random samples of the air populations originating from winter and spring barley fields were obtained by means of a mobile version of a jet spore sampler. Conidia were sampled by driving across the Czech Republic. In total 349 isolates were studied and 17 differentials were used. The virulence frequencies to specific resistances of given cultivars showed wide range from 0% to 100%. Nine differentials were used to distinguish 134 pathotypes, of which 32 representing 63.9% of isolates were detected in both years. Pathotype 773, which broke down the resistance of eight differentials, was the most abundant. In 2008, lower virulence frequencies to all differentials, and thus lower population complexity, were determined, which may be caused by different regional origins of the isolates examined. Importance of the study of the given pathogen population is discussed in terms of successful breeding of resistant barley cultivars.

scholarly journals Virulence frequencies to powdery mildew resistance genes of winter barley cultivars

2010 ◽  
Vol 40 (No. 4) ◽  
pp. 135-140 ◽  
Author(s):  
A. Dreiseitl
Keyword(s):  
Czech Republic ◽  
Powdery Mildew ◽  
Resistance Genes ◽  
Powdery Mildew Resistance ◽  
Spring Barley ◽  
Winter Barley ◽  
The Czech Republic ◽  
Mildew Resistance ◽  
Barley Cultivars ◽  
Random Samples

The virulence frequencies to powdery mildew resistance genes possessed by winter barley cultivars registered and newly tested in the Czech Republic were studied in 2000, 2002 and 2004. Random samples of the populations originating from winter and spring barley fields were obtained from the air by a mobile version of a jet spore sampler mounted on a car roof. Conidia were sampled by driving across the Czech Republic. Fourteen differentials, carrying 18 out of 20 currently identified resistance genes present in winter barley cultivars, were used. High virulence frequencies (85–100%) to most resistance genes were found. Lower virulence frequencies (14.1–40.1%) were found to only three resistance genes that have not been described yet; their preliminary designations are Ml(Va), Ml(Dt) and Ml(Ca). The importance of resistance of winter barley cultivars is discussed with respect to limiting the speed with which the pathogen adapts to genetic resistances possessed by commercial cultivars of both winter and spring barley, and to the necessity of lowering the costs for powdery mildew control in barley.

scholarly journals  Presence of the newly designated powdery mildew resistance Landi in some winter barley cultivars

2011 ◽  
Vol 47 (No. 2) ◽  
pp. 64-68 ◽  
Author(s):  
A. Dreiseitl
Keyword(s):  
Czech Republic ◽  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Winter Barley ◽  
The Other ◽  
The Czech Republic ◽  
Barley Cultivars ◽  
Unknown Gene ◽  
Powdery Mildew Pathogen ◽  
Pathogen Populations

In the last two decades, resistance to the powdery mildew pathogen has been investigated in a large number of barleys in the Czech Republic. Several tens of winter barley cultivars were identified with a resistance based on an unknown gene or unknown combinations of resistance genes. In this paper tests on 20 of these cultivars are presented. Thirty-two reference isolates of Blumeria graminis f.sp. hordei were used. All the 20 cultivars shared a particular, previously unknown resistance. Landi was the first cultivar registered with this resistance and it is recommended that this resistance be designated Ln. Isolates virulent to Ln were already found randomly in old European, and also in non-European pathogen populations, where cultivars possessing the resistance Ln were never grown. On the other hand, the resistance Ln has been highly effective even 13 years after Landi registration.

Emerging Blumeria graminis f. sp. hordei pathotypes reveal ‘Psaknon’ resistance in European barley varieties

2015 ◽  
Vol 154 (6) ◽  
pp. 1082-1089 ◽  
Author(s):  
A. DREISEITL
Keyword(s):  
Powdery Mildew ◽  
Central Europe ◽  
Powdery Mildew Resistance ◽  
Quantitative Resistance ◽  
Spring Barley ◽  
Blumeria Graminis ◽  
Winter Barley ◽  
Cereal Crops ◽  
Alternative Source ◽  
The Czech Republic

SUMMARYBarley (Hordeum vulgare L.) is one of the most important cereal crops in the world and powdery mildew caused by the airborne fungus Blumeria graminis f. sp. hordei is a worldwide disease that causes frequent epidemics in Central and Northwestern Europe. Psaknon was one of first varieties in which powdery mildew resistance (Mlp1) was found, but no commercial variety with this resistance and no pathotype with the corresponding virulence have been recorded. In 2014, four isolates collected in the Czech Republic and virulent to Mlp1 were tested on 25 varieties and were also virulent to seven other resistances, including Venezia. These isolates revealed the presence of Mlp1 in six commercial spring and winter barley varieties from Southeastern and Central Europe and in six German winter barley candidate lines for registration in Czech variety trials. Based on the combined results of virulence and resistance, it was concluded that Vp1 is becoming a major factor contributing to increased virulence complexity and pathotype diversity in Central Europe. In breeding, employment of the non-specific resistance Mlo for spring barley and accumulation of quantitative resistance genes for winter barley can still be recommended in addition to exploiting a non-host resistance from an alternative source such as that present in Hordeum bulbosum.

scholarly journals Virulence analyses of the powdery mildew population on wheat in the CzechRepublic in 1995–1998

1999 ◽  
Vol 35 (No. 2) ◽  
pp. 57-62
Author(s):  
K. Klem
Keyword(s):  
Czech Republic ◽  
Powdery Mildew ◽  
Blumeria Graminis ◽  
Spore Trap ◽  
Gametic Disequilibrium ◽  
The Czech Republic ◽  
High Frequencies ◽  
B Values ◽  
One Year ◽  
Virulence Frequency

In 1995–1998, the frequency of selected virulences in the powdery mildew ( Blumeria graminis f. sp. tritici ) population on wheat in the Czech Republic was investigated. Samples of conidia were collected by a mobile version of a spore-trap. A total of 1739 one-colony isolates were analysed on a set of five varieties as differentials. High frequencies (> 50%)  were found for virulences Vm2, Vm3a, Vm5 and Vml7, lower frequencies(< 50%) for combinations Vm9,2,1 and Vm2,6 and for Vm4b. There were no significant changes in virulence frequencies except for genes Vm5 and Vm9,2,1 that showed one-year variations. Differences between the eastern part (Moravia) and western part (Bohemia) of the Czech Republic were mostly insignificant for most exam­ ined genes. A significantly higher virulence frequency was found in Moravia for genes Vm3a (in 1995) and Vml7 (in 1996), and in Bohemia for the combination Vm9,2,1 (in 1995). A significant correlation (tested by Kendall's tau B values) existed between Vm2 and Vm5 in 1997 and 1998, and between Vm4b and Vm5 in 1995 and 1998. Values of gametic disequilibrium were also studied. Changes in the complexity of isolate virulence were determined to be small and showed no definite trend.  

scholarly journals Blumeria graminis f. sp. hordei virulence frequency and the powdery mildew incidence on spring barley in the Wielkopolska province

2014 ◽  
Vol 54 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Anna Tratwal ◽  
Jan Bocianowski
Keyword(s):  
Powdery Mildew ◽  
Spring Barley ◽  
Weather Conditions ◽  
Blumeria Graminis ◽  
Meteorological Conditions ◽  
Powdery Mildew Fungus ◽  
Barley Cultivars ◽  
Virulence Frequency

Abstract Powdery mildew caused by fungi Blumeria graminis f. sp. hordei is one of the most common barley diseases in Polish meteorological conditions. The powdery mildew fungus is made up of different races and forms that are highly specialized. Barley cultivars might be resistant to a certain race of the mildew fungus, but susceptible to another race. Development of the disease is rapid in temperatures from 12 to 20°C, and in humid weather. The aim of the two-year experiment was to assess B. graminis f. sp. hordei virulence frequency and powdery mildew occurrence on five spring barley cultivars. Virulence frequency of the pathogen depended on place and term of exposition. The occurrence of powdery mildew on spring barley cultivars depended on virulence frequency of the pathogen and weather conditions.

scholarly journals Callus induction and regeneration efficiency of spring barley cultivars registered in the Czech Republic

2011 ◽  
Vol 50 (No. 10) ◽  
pp. 456-462 ◽  
Author(s):  
V. Šerhantová ◽  
J. Ehrenbergerová ◽  
L. Ohnoutková
Keyword(s):  
Czech Republic ◽  
Callus Induction ◽  
Callus Formation ◽  
Spring Barley ◽  
Zygotic Embryos ◽  
Golden Promise ◽  
The Czech Republic ◽  
Barley Cultivars ◽  
Regeneration Efficiency

Immature zygotic embryos are frequently used for induction of cell cultures in vitro and for genetic transformation. The effect of three synthetic auxins: 2,4-dichlorophenoxyacetic acid (2,4-D), 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 4-amino-3,5,6-trichloropicolinic acid (picloram) on induction and subsequent regeneration capacity of barley. In vitro culture was studied in 12 spring barley cultivars registered in the Czech Republic and a variety of Golden Promise, with known high regeneration efficiency. The callus formation frequency and number of green regenerants were influenced significantly both by genotype and auxin. Most cultivars formed statistically significantly a higher mean number of regenerants (1.95) after the callus induction on the medium with 2.4-D as compared to the media with picloram and dicamba. Only two cultivars (Nordus and SG-S-261) did not respond to the used auxins differently. The highest average number of regenerants (from all three auxins) was obtained with Golden Promise (2.7 plants per one cultivated scutellum). From the set of genotypes used in our study, the cultivars Atribut, Forum, and Scarlett with the mean number of regenerants (2.09–1.57) would be the most suitable cultivars for further transformation use. They differ statistically significantly from the cultivars Nordus, Amulet, Akcent, SG-S-252, Orbit, and Granát (0.42–0.92) which had the lowest mean number of regenerants.

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