scholarly journals Expression of resistance to Ramularia leaf spot in winter barley cultivars grown in conditions of the Czech Republic

2011 ◽  
Vol 47 (No. 1) ◽  
pp. 37-40 ◽  
Author(s):  
P. Mařík ◽  
Z. Šnejdar ◽  
P. Matušinsky
Keyword(s):  
Czech Republic ◽  
High Resistance ◽  
Leaf Spot ◽  
Experimental Period ◽  
Winter Barley ◽  
Leaf Spot Disease ◽  
The Czech Republic ◽  
Breeding Lines ◽  
Barley Cultivars ◽  
Ramularia Leaf Spot

The fungus Ramularia collo-cygni is increasingly important as the causal agent of Ramularia leaf spot (RLS), a novel leaf spot disease of barley. The work aimed to identify gene resources suitable for developing new breeding lines of winter barley with improved resistance. During the first experimental period (2001–2005), RLS incidence was monitored in 711 cultivars and advanced breeding lines. Differences were detected in the intensity of symptomatic expression, but no material showed high resistance. During the second experimental period (2006–2009), response to natural RLS infection was evaluated in 19 winter barley cultivars (12 six-row and 7 two-row) registered in the Czech Republic. Highest susceptibility was detected in 6-row cvs. Luran, Laverda and Wendy while cvs Breunskylie (2-row), Merlot and Highlight (both 6-row) showed relatively lower disease incidence. High resistance was not detected. On average, 2-row cultivars showed lower intensity than 6-row cultivars and significant variation was observed among years.

Response of spring barley cultivars to Ramularia leaf spot in conditions of the Czech Republic

2013 ◽  
Vol 41 (1) ◽  
pp. 126-132 ◽  
Author(s):  
P. Matušinsky ◽  
M. Hanusová ◽  
L. Stemberková ◽  
P. Mařík ◽  
V. Minaříková ◽  
...  
Keyword(s):  
Czech Republic ◽  
Leaf Spot ◽  
Spring Barley ◽  
The Czech Republic ◽  
Barley Cultivars ◽  
Ramularia Leaf Spot

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 Peronospora hariotii on Buddleja in the Czech Republic

2009 ◽  
Vol 45 (No. 1) ◽  
pp. 12-15
Author(s):  
I. Šafránková ◽  
J. Müller
Keyword(s):  
Czech Republic ◽  
Downy Mildew ◽  
Leaf Spot ◽  
Leaf Spot Disease ◽  
Sexual Stage ◽  
The Czech Republic ◽  
Spot Disease ◽  
Microscopic Features ◽  
Butterfly Bush ◽  
Downy Mildew Disease

A downy mildew was observed on <I>Buddleja × weyeriana</I> Weyer ex Rehd. (<I>B. davidii × globosa</I>) cv. Sungold in a nursery in the northern part of the Czech Republic in July 2008. This downy mildew disease of <I>Buddleja</I> (Butterfly Bush) had been unknown in the country so far. Characteristics of visual symptoms and microscopic features are described. The morphology of the fungus was typical for <I>Peronospora hariotii</I>, conforming to the published description by GÄUMANN (1919). The sexual stage was not found. This is the first report of <I>Peronospora hariotii </I>causing leaf spot disease on <I>Buddleja</I> in the Czech Republic.

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.

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 Forecasting system for infection risk of phoma stem canker in selected regions of the Czech Republic in 2009–2011 

2014 ◽  
Vol 50 (No. 1) ◽  
pp. 8-16 ◽  
Author(s):  
J. Poslušná ◽  
E. Plachká
Keyword(s):  
Czech Republic ◽  
Leaf Spot ◽  
Weather Conditions ◽  
Stem Canker ◽  
Infection Risk ◽  
Risk Of Infection ◽  
The Czech Republic ◽  
Phoma Stem Canker ◽  
Ascospore Release ◽  
Forecasting System

In the period 2009&ndash;2011 monitoring of the incidence of phoma stem canker was carried out at selected sites of the Czech Republic (&Scaron;umperk and Opava regions in North Moravia). The risk of infection was evaluated by assessing the autumn release of&nbsp;Leptosphaeria&nbsp;spp. ascospores and with the proPlant prediction model. In recent years, the incidence of phoma stem canker has been relatively low and this corresponded with the total count of ascospores released in the autumn period but not with an increased level of infection risk announced by the proPlant model. During the monitored period the ascospore concentration reached maximally 2 ascospores/1 m<sup>3</sup>&nbsp;per day. Maximum ascospore release was recorded in 2010 as a result of favourable weather conditions. The first incidence of phoma leaf spot has been observed in mid-October. The higher values of ascospores concentration were recorded in the Opava region, but the total number of the trapped ascospores was more often higher in the &Scaron;umperk region.&nbsp;

scholarly journals Severity of powdery mildew on winter barley in the Czech Republic in 1976–2005

2008 ◽  
Vol 43 (No. 3) ◽  
pp. 77-85 ◽  
Author(s):  
A. Dreiseitl
Keyword(s):  
Czech Republic ◽  
Powdery Mildew ◽  
Disease Severity ◽  
Field Trials ◽  
Winter Barley ◽  
Sources Of Resistance ◽  
The Czech Republic ◽  
High Infection ◽  
High Disease Severity ◽  
Important Disease

Results of scoring the reaction to powdery mildew of 240 winter barley varieties that were gradually included in 392 Czech Official Trials conducted at 21 locations were analysed. The reaction of the varieties was determined on the basis of the level of infection by the disease. Therefore, the data can also be used to assess the disease severity in years and at locations. Several characteristics indicative of disease severity were considered, including the disease severity coefficient (= average infection of susceptible varieties in trials with a high disease severity/the proportion of such trials). The value of the coefficient is inversely proportional to disease severity. The highest powdery mildew severity was found in 1976, and the years 1988, 1990 and 2003 were characterised by high infection of the examined varieties. In contrast, the disease was practically absent in 1979 and 1982, and its severity was also low in 1978, 1981, 1985, 1991 and 1998. Very low disease severity was found for the period 1977–1982 when insufficient disease severity was found on average in 78% of the trials and high disease severity in only 6% of the trials. The highest disease severity was found at locations Trutnov, Horažďovice and Chrastava. The analysis of data from a large number of field trials conducted at various locations for a period of 30 years confirmed that powdery mildew is an important disease of winter barley in the Czech Republic. Known genetic sources of resistance and current methods, such as marker assisted selection, enable breeders to solve this problem.

scholarly journals Occurrence of rust disease caused by Puccinia oxalidis on Oxalis triangularis in the Czech Republic – Short Communication 

2014 ◽  
Vol 50 (No. 1) ◽  
pp. 17-18
Author(s):  
I. Šafránková
Keyword(s):  
Czech Republic ◽  
Leaf Spot ◽  
Short Communication ◽  
Rust Disease ◽  
The Czech Republic ◽  
First Report ◽  
Microscopic Features

This is the first report of&nbsp;Puccinia oxalidis&nbsp;causing leaf spot diseases on ornamental&nbsp;Oxalis triangularis&nbsp;subsp.&nbsp;papilionaceae&nbsp;cv. Atropurpurea in Moravia, Czech Republic. The macroscopic symptoms and microscopic features are described.

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