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 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 Identity of barley powdery mildew resistances Bw and Ru2

2012 ◽  
Vol 48 (No. 4) ◽  
pp. 185-188 ◽  
Author(s):  
A. Dreiseitl
Keyword(s):  
Hordeum Vulgare ◽  
Powdery Mildew ◽  
Spring Barley ◽  
Blumeria Graminis ◽  
Winter Barley ◽  
Barley Cultivar ◽  
Hordeum Vulgare L ◽  
Barley Line ◽  
Barley Powdery Mildew ◽  
The Difference

A large number of resistances to powdery mildew (Blumeria graminis f.sp. hordei) and their combinations are known in barley (Hordeum vulgare L.). A similarity of resistance spectra between cultivars carrying the resistance Bw, designated for the winter barley cultivar Borwina, and the near-isogenic spring barley line P15, which carries the resistance Ru2, derived from the landrace Rupee, was found. The objective of this study was to test the difference between resistances Bw and Ru2. Six cultivars were tested, four with Bw and two with Ru2. Testing with 40 isolates showed identical reaction spectra between both groups. Testing of the cultivar Kompolti 4 (Bw) and line P15 (Ru2) with 300 isolates confirmed this result. Thus, the resistances currently designated Bw and Ru2 can be regarded as identical, and are determined by the gene Ml(Ru2). Both Bw and Ru2 should be designated by the earlier code, Ru2.

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 Mlo Resistance to Powdery Mildew (Blumeria graminis f. sp. hordei) in Barley Landraces Collected in Yemen

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1582
Author(s):  
Jerzy H. Czembor ◽  
Elżbieta Czembor
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Yield Loss ◽  
Blumeria Graminis ◽  
Cereal Crops ◽  
Single Plant ◽  
Breeding Programs ◽  
Barley Powdery Mildew ◽  
Barley Landraces ◽  
Avirulent Isolate

Barley (Hordeumvulgare L.) is one of the most important cereal crops in the world. Powdery mildew on barley, which is caused by the pathogen Blumeria graminis f. sp. hordei, occurs world-wide and can result in severe yield loss. Thousands of barley accessions are stored in national gene banks, and their characterization for breeding purposes is needed. This study was conducted to determine the resistance to powdery mildew in 33 barley landraces from Yemen, which were obtained from the ICARDA gene bank. Twenty differential isolates of barley powdery mildew were used. Nine single plant lines were selected from five landraces, based on tests that were performed with 30 plants per landrace, after inoculation with the most avirulent isolate of barley powdery mildew available. Two of these landraces originated from the Al Bayda province in Yemen, and three others originated from Dhamar, Sanaa, and Taizz, respectively. Next, single plant lines were tested using a set of 20 differential isolates of powdery mildew. Two lines that were selected from landrace from the Al Bayda province in Yemen, showed disease reaction designated as 0(4), which is specific for the presence of Mlo resistance. The new source of highly effective Mlo powdery mildew resistance that is described in this study could be used in barley breeding programs.

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 Variety resistance of winter barley to powdery mildew in the field in 1976−2005

2008 ◽  
Vol 43 (No. 3) ◽  
pp. 87-96 ◽  
Author(s):  
A. Dreiseitl
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Powdery Mildew Resistance ◽  
Specific Resistance ◽  
Winter Barley ◽  
Mildew Resistance ◽  
Average Resistance ◽  
The Difference ◽  
The Given ◽  
Resistance Of Varieties

The results of evaluation of powdery mildew resistance in winter barley varieties in 285 Czech Official Trials conducted at 20 locations were analysed. Over the period, the number of varieties tested per year increased from four to seven in 1976−1985 to 53−61 in 2002−2005. To assess the resistance of varieties, only trials with sufficient disease severity were used. In 1976−2000, six varieties (1.7% of the varieties tested in the given years) ranked among resistant (average resistance of a variety in a year > 7.5) including NR-468 possessing the gene <i>Mla13</i>, KM-2099 with <i>mlo</i> and Marinka with the genes <i>Mla7</i>, <i>MlaMu2</i>. In 2001−2005, already 33 varieties (16.9%) ranked among resistant, of which Traminer possessing the genes <i>Ml(St)</i> and <i>Ml(IM9 </i> dominated. The proportion of susceptible varieties (average resistance ≤ 5.5) did not change in the two mentioned periods. Two-rowed varieties began to be tested as late as in 1990 (the first variety was Danilo), however, no difference was found in the resistance of two- and six-rowed varieties. Using an example of two pairs of varieties (Dura-Miraj and Marinka-Tiffany) with identical genes for specific resistance but with different resistance in the field, the efficiency of non-specific resistance is discussed. The resistance of domestic and foreign varieties was similar in 1994−2000; however, in 2001−2005 the difference was 0.75 point to disadvantage of domestic ones.

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 Specific Resistance of Barley to Powdery Mildew, Its Use and Beyond: A Concise Critical Review

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 971 ◽  
Author(s):  
Antonín Dreiseitl
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Plant Pathogens ◽  
Specific Resistance ◽  
Wide Spectrum ◽  
Quantitative Resistance ◽  
Spring Barley ◽  
Durable Resistance ◽  
Genetic Resistance ◽  
Barley Cultivars

Powdery mildew caused by the airborne ascomycete fungus Blumeria graminis f. sp. hordei (Bgh) is one of most common diseases of barley (Hordeum vulgare). This, as with many other plant pathogens, can be efficiently controlled by inexpensive and environmentally-friendly genetic resistance. General requirements for resistance to the pathogens are effectiveness and durability. Resistance of barley to Bgh has been studied intensively, and this review describes recent research and summarizes the specific resistance genes found in barley varieties since the last conspectus. Bgh is extraordinarily adaptable, and some commonly recommended strategies for using genetic resistance, including pyramiding of specific genes, may not be effective because they can only contribute to a limited extent to obtain sufficient resistance durability of widely-grown cultivars. In spring barley, breeding the nonspecific mlo gene is a valuable source of durable resistance. Pyramiding of nonspecific quantitative resistance genes or using introgressions derived from bulbous barley (Hordeum bulbosum) are promising ways for breeding future winter barley cultivars. The utilization of a wide spectrum of nonhost resistances can also be adopted once practical methods have been developed.

Sign in / Sign up

Export Citation Format

Share Document