scholarly journals Powdery Mildew Resistance Genes in Single-Plant Progenies Derived from Accessions of a Winter Barley Core Collection

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1988
Author(s):  
Antonín Dreiseitl ◽  
Zdeněk Nesvadba
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Core Collection ◽  
Powdery Mildew Resistance ◽  
Gene Bank ◽  
Winter Barley ◽  
Single Plant ◽  
Mildew Resistance ◽  
Gene Banks ◽  
Reliable Source

The main problems of crop gene banks comprise heterogeneity of accessions, resulting from mechanical admixtures or out-crossing during their multiplication, and especially the mislabeling of accessions. These discrepancies can adversely affect the results of many expensive research and breeding projects that are based on the use of gene bank resources. To tackle these problems, 860 single-plant progenies (SPPs) of 172 accessions of the Czech winter barley core collection were grown and tested with a set of 53 isolates representing the global virulence/avirulence diversity of powdery mildew. Seventy-one resistance phenotypes encompassed the diversity of known specific resistances and their combinations. Based on testing groups of five SPPs, 94 accessions had one phenotype found in all five SPPs (homogeneous accessions), whereas in 78 accessions (45.3%) more than one phenotype was identified (heterogeneous accessions). In three varieties, specific resistances against the whole set of isolates were detected, but due to high adaptability of the pathogen, they are not recommended for breeding resistant cultivars. Selected SPPs were integrated in the gene bank and are now a reliable source of genotypically pure seed with defined powdery mildew resistance genes that can be used by breeders and researchers. The results obtained can be used to verify authenticity of accession genotype and pedigree, particularly for older varieties for which no other original criteria are available.

scholarly journals Genotype Heterogeneity in Accessions of a Winter Barley Core Collection Assessed on Postulated Specific Powdery Mildew Resistance Genes

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 513
Author(s):  
Antonín Dreiseitl
Keyword(s):  
Resistance Genes ◽  
Core Collection ◽  
Powdery Mildew Resistance ◽  
Gene Bank ◽  
Winter Barley ◽  
The Core ◽  
Genotype Identification ◽  
Environmentally Safe ◽  
Mla Locus ◽  
Resistance Tests

Gene bank accessions are necessary for implementing many research and breeding projects. However, a great number of accessions are contaminated or confused. If such accessions are used, the results obtained from these projects are inaccurate and non-reproducible. There are methods that allow almost perfect genotype identification; nevertheless, they are relatively recent and results cannot be compared with the characteristics of the original accessions. Growing resistant cultivars is an environmentally safe and cheap way of disease management and knowledge of diverse resistance genes and their combinations can be used to identify varieties and verify their authenticity and homogeneity. For this purpose, all 172 accessions of the core collection (CC) of the Czech winter barley (Hordeum vulgare) gene bank, originating from 35 countries, were studied. For resistance tests, 51 reference isolates of Blumeria graminis f. sp. Hordei, collected in all nonpolar continents over a period of 63 years and representing the global virulence/avirulence diversity of the pathogen, were used. Only 25 barley accessions were homogeneous (genetically uniform), whereas 147 accessions were heterogeneous due to presence of different genotypes. In total, 17 resistance genes were found singly or in combinations; 76.3% of accessions with identified resistance genes carried alleles at the Mla locus. To purify the CC, progenies of individual plants must be multiplied and authenticity and homogeneity of the seed should be confirmed with resistance tests, and subsequently can be studied with more advanced methods.

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.

Identification and SSR Mapping of Two Powdery Mildew Resistance Genes in Wild Emmer (Triticum dicoccoides) Accessions IW3 and IW10

2009 ◽  
Vol 35 (5) ◽  
pp. 761-767 ◽  
Author(s):  
Gen-Qiao LI ◽  
Ti-Lin FANG ◽  
Hong-Tao ZHANG ◽  
Chao-Jie XIE ◽  
Zuo-Min YANG ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Powdery Mildew Resistance ◽  
Triticum Dicoccoides ◽  
Wild Emmer ◽  
Mildew Resistance

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.

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