scholarly journals Assessment of powdery mildew (Blumeria graminis f. sp. hordei) resistance genes in Turkish barley varieties

2009 ◽  
Vol 89 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Ahmet Zeybek ◽  
Şahin Dere ◽  
Gülay Gök ◽  
Asude Çallak ◽  
Mahinur S. Akkaya
Keyword(s):  
Hordeum Vulgare ◽  
Powdery Mildew ◽  
Resistance Genes ◽  
Blumeria Graminis ◽  
Leaf Segment ◽  
R Gene ◽  
R Genes ◽  
Resistant Varieties

Thirty-four Turkish barley (Hordeum vulgare) varieties were tested for the presence of resistance genes (R-genes) to powdery mildew (Blumeria graminisf. sp.hordei) using the “leaf segment test” with nine isolates of the fungus. The most commonly found R-gene wasMla8, while a combination of R-genesMlgandMl(CP)was found in three varieties (Tokak 157/37, Beysehir 98, Konevei 98). The geneMlhwas found in four varieties (Obruk 86, Anadolu 86, Çıldır 02, Özdemir 05), while no R-gene was found in three varieties (Hamidiye 85, Yesevi 93, Bülbül 89). No clear inferences could be made for the partly-resistant varieties Gemici 7243, Yea 793.12 and Akhisar 98 using the test isolates selected, which suggests the presence of still unidentified R-genes. Overall, 10 previously characterized R-genes for powdery mildew (Mla8,Ml(La),Mlg,Ml(CP),Mlh,Mlat,Mla1,Mlh,Mla7,Mlra) were present in Turkish barley varieties, along with some other(s) still to be identified.

scholarly journals Evaluation of resistance to powdery mildew and identification of resistance genes in wheat cultivars

2020 ◽  
Author(s):  
Xian Xin Wu ◽  
Yue Gao ◽  
Qiang Bian ◽  
Qian Sun ◽  
Xin Yu Ni ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Large Scale ◽  
Durable Resistance ◽  
Cost Effective ◽  
Blumeria Graminis ◽  
Wheat Cultivars ◽  
Seedling Resistance ◽  
Initial Inoculum ◽  
Wheat Powdery Mildew

Abstract Background: Wheat powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici ( Bgt ), is a serious disease of wheat worldwide that can cause significant yield losses. Growing resistant cultivars is the most cost-effective and eco-soundly strategy to manage the disease. Therefore, a high breeding priority is to identify genes that can be readily used either singly or in combination for effective resistance to powdery mildew and alos in combination with genes for resistance to other diseases. Yunnan Province, with complex and diverse ecological environments and climates, is one of the main wheat growing regions in China. This region provides initial inoculum for starting epidemics of wheat powdery mildew in the region and other regions and thus, plays a key role in the regional and large-scale epidemics of the disease throughout China. The objectives of this study were to evaluate seedling resistance of 69 main wheat cultivars to powdery mildew and to determine the presence of resistance genes Pm3 , Pm8 , Pm13 , Pm16 , and Pm21 in these cultivars using gene specific DNA markers. Results: Evaluation of 69 wheat cultivars with six Bgt isolates showed that only four cultivars were resistant to all tested isolates, indicating that the overall level of powdery mildew resistance of Yunnan wheat cultivars is inadequate. The molecular marker results showed that 27 cultivars likely have at least one of these genes. Six cultivars were found likely to have Pm3 , 18 likely to have Pm8 , 5 likely to have Pm16 , and 3 likely to have Pm21 . No cultivar was found to carry Pm13 . Conclusion: The information on the presence of the Pm resistance genes in Yunnan wheat cultivars can be used in future wheat disease breeding programs. In particular, cultivars carrying Pm21 , which is effective against all Bgt races in China, should be pyramided with other effective genes to developing new cultivars with durable resistance to powdery mildew. Keywords: Blumeria graminis f. sp. tritici , Pm gene, molecular markers, wheat

Arabidopsis thaliana: A source of candidate disease-resistance genes for Brassica napus

Genome ◽  
2000 ◽  
Vol 43 (3) ◽  
pp. 452-460 ◽  
Author(s):  
D Sillito ◽  
I AP Parkin ◽  
R Mayerhofer ◽  
D J Lydiate ◽  
A G Good
Keyword(s):  
Arabidopsis Thaliana ◽  
Disease Resistance ◽  
Brassica Napus ◽  
Resistance Genes ◽  
Plant Disease Resistance ◽  
Disease Resistance Genes ◽  
R Gene ◽  
R Genes ◽  
Rapid Divergence ◽  
Genomic Regions

Common structural and amino acid motifs among cloned plant disease-resistance genes (R genes), have made it possible to identify putative disease-resistance sequences based on DNA sequence identity. Mapping of such R-gene homologues will identify candidate disease-resistance loci to expedite map-based cloning strategies in complex crop genomes. Arabidopsis thaliana expressed sequence tags (ESTs) with homology to cloned plant R genes (R-ESTs), were mapped in both A. thaliana and Brassica napus to identify candidate R-gene loci and investigate intergenomic collinearity. Brassica R-gene homologous sequences were also mapped in B. napus. In total, 103 R-EST loci and 36 Brassica R-gene homologous loci were positioned on the N-fo-61-9 B. napus genetic map, and 48 R-EST loci positioned on the Columbia × Landsberg A. thaliana map. The mapped loci identified collinear regions between Arabidopsis and Brassica which had been observed in previous comparative mapping studies; the detection of syntenic genomic regions indicated that there was no apparent rapid divergence of the identified genomic regions housing the R-EST loci.Key words: RFLP mapping, candidate R genes, R-gene homologues, genomic collinearity, Arabidopsis ESTs.

scholarly journals Deriving isolates of powdery mildew (Blumeria graminis DC. f.sp. avenae Em. Marchal.) in common oat (Avena sativa L.) and using them to identify selected resistance genes

2012 ◽  
Vol 65 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Sylwia Okoń ◽  
Krzysztof Kowalczyk
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Avena Sativa ◽  
Blumeria Graminis ◽  
Matching Model ◽  
F2 Population ◽  
Host Pathogen ◽  
Dominant Genes

Powdery mildew in common oat is caused by <i>Blumeria graminis</i> DC. f.sp. <i>avenae</i> Em. Marchal. Host-pathogen tests are commonly used to identify and locate resistance genes to powdery mildew in cereals. The aim of the study was to determine the virulence of powdery mildew isolates obtained from powdery mildew populations harvested in Poland and to identify OMR1, OMR2 and OMR3 resistance genes to powdery mildew in F<sub>2</sub> populations of inter-cultivar hybrids of common oat: Bruno × Fuchs, Jumbo × Fuchs and Mostyn × Fuchs. On the basis of the analysis conducted, isolates enabling division of the studied populations into groups of resistant and susceptible plants were selected. M10 and M14 isolates were chosen for the population which was obtained from crossbreeding of ‘Bruno’ with ‘Fuchs’; these isolates demonstrated avirulence to Bruno cultivar containing OMR1 gene. In order to divide population obtained from crossbreeding of ‘Jumbo’ with ‘Fuchs’, M13 and M16 isolates were chosen; they demonstrated avirulence to the cultivar Jumbo containing the OMR2 gene. On the basis of the tests conducted, it was impossible to select isolates characterised by avirulence to the OMR3 gene. In the F2 population of Bruno × Fuchs and Jumbo × Fuchs hybrids, a division was made into resistant and susceptible plants. The obtained results were verified by the <sup>2</sup> test; the proportion in the dispersion matching model was found to be 3 resistant plants: 1 sensitive plant both in the Bruno × Fuchs and Jumbo × Fuchs populations. Such dispersion indicated that the resistance to powdery mildew in the studied cultivars Bruno and Jumbo was conditioned by single dominant genes.

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&nbsp;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&nbsp;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 Search for donors of powdery mildew resistance genes among seedless and table grape varieties

2021 ◽  
Vol 39 ◽  
pp. 02005
Author(s):  
Marina Makarkina ◽  
Elena Ilnitskaya ◽  
Tatiana Kozina
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Dna Markers ◽  
Table Grape ◽  
Main Method ◽  
Chemical Treatments ◽  
Pesticide Treatment ◽  
Resistant Varieties ◽  
Allelic Status ◽  
Grape Varieties

Powdery mildew (Erysiphe necator) is one of the most common and economically significant diseases of grapes. Currently, the main method of controlling the disease is pesticide treatment. Breeding of resistant varieties is necessary to reduce chemical treatments. Currently, a number of grape resistance genes to powdery mildew and DNA markers for identification the allelic status of these genes are known. In a study to determine the presence of resistance loci Ren3 and Ren9, 25 genotypes of table grape varieties were analyzed, including 18 seedless varieties. DNA markers GF15-42, ScORGF15-02 were used to identify Ren3 gene, and CenGen6 – to identify Ren9 gene. DNA of cultivars Regent and Seyve Villard 12-375, which have resistance alleles, were used as positive controls. As a result of DNA marker analysis, it was determined that genotypes of table varieties Viking, Kodryanka, Moldova, Nadezhda AZOS, Original and seedless varieties Pamyati Smirnova, Kishmish Zaporozhskiy and Kishmish 342 carry loci of resistance to powdery mildew Ren3 and Ren9.

scholarly journals Variability of the wheat powdery mildew pathogen Blumeria graminis f. sp. tritici in the 2003 crop season

2005 ◽  
Vol 30 (4) ◽  
pp. 420-422 ◽  
Author(s):  
Leila M. Costamilan
Keyword(s):  
Triticum Aestivum ◽  
Powdery Mildew ◽  
Resistance Genes ◽  
Genetic Resistance ◽  
Blumeria Graminis ◽  
Wheat Cultivars ◽  
Crop Season ◽  
Grain Yields ◽  
Wheat Powdery Mildew ◽  
Powdery Mildew Pathogen

Wheat (Triticum aestivum) powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici, is one of the most severe foliar diseases attacking this crop, reducing grain yields by 10% to 62% in Brazil. The disease can be controlled by genetic resistance of the host, but the pathogen has physiological specialization, which enables it to infect wheat cultivars that have remained resistant for years. The objective of this work was to evaluate the variability of pathogenic strains of B. graminis f. sp. tritici collected in Brazil and the effectiveness of wheat resistance genes to powdery mildew in the 2003 crop season. Plants of a differential series were inoculated with each monopustular isolate. Thirty-one combinations of effective and ineffective resistance genes were identified. Only the gene Pm4a+... remained totally effective to all isolates, and gene Pm6 was highly effective (below 10% of susceptibility), whereas genes Pm3a and Pm8 were totally ineffective (susceptible to all isolates). Genes Pm3c, D1, and D2 showed low effectiveness (above 50% of susceptibility), and genes Pm1, 2, 4a, 1+?, and 2+Mld had mean effective results to most strains (susceptibility between 10% and 49%). The virulence formula Pm1, 3c, 4a, 6, 1+?, 2+Mld, 4a+..., D2 (effective genes) / 2, 3a, 8, D1 (ineffective genes) was most frequently found, accounting for 15% of the occurrences. The most frequent number of ineffective genes was seven, ranging from three to ten.

RFLP markers linked to powdery mildew resistance genes Pm1, Pm2, Pm3, and Pm4 in wheat

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 871-875 ◽  
Author(s):  
Z. Q. Ma ◽  
M. E. Sorrells ◽  
S. D. Tanksley
Keyword(s):  
Triticum Aestivum ◽  
Powdery Mildew ◽  
Resistance Genes ◽  
Polymorphic Locus ◽  
Triticum Aestivum L ◽  
Blumeria Graminis ◽  
Rflp Markers ◽  
Recurrent Parent ◽  
Polymorphic Markers ◽  
Restriction Fragment Length Polymorphic

Near-isogenic lines (NILs) and their recurrent parent Chancellor (Cc) were used to identify restriction fragment length polymorphic markers linked to powdery mildew (Blumeria graminis (DC.) E.O. Speer f.sp. tritici) resistance genes Pm1, Pm2, Pm3, and Pm4 in wheat (Triticum aestivum L. em. Thell). By mapping these polymorphic markers in F2 progenies from crosses of the NILs with Cc, it was found that Pm1 cosegregated with a polymorphic locus detected by DNA probe CDO347; Pm2 was linked to a locus detected by probe BCD1871 with a distance of 3.5 cM; Pm3b was linked to a locus detected by probe BCD1434 with a distance of 1.3 cM; Pm4a cosegregated with Xbcd1231-2A(2) and Xcdo678-2A, and was closely flanked by Xbcd1231-2A(1) and Xbcd292-2A both with a distance of 1.5 cM. Aneuploid mapping of these markers indicated that locus Xcdo347-7A is on 7AL, Xbcd1871-5D on 5DS, Xbcd1434-1A on 1AS, and loci Xbcd292-2A and Xcdo678-2A are on 2AL. The same polymorphic fragments detected in the Pm3b NIL by Xbcd1434-1A were found in Pm3a NIL using several enzyme digestions.Key words: RFLP markers, Pm1, Pm2, Pm3, Pm4, Blumeria graminis (DC.) E.O. Speer f.sp. tritici (Erysiphe graminis f.sp. tritici), wheat (Triticum aestivum L. em. Thell), gene tagging.

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