Haplotype characterization and markers at the barley Mlo powdery mildew resistance locus as tools for marker-assisted selection

Genome ◽  
2006 ◽  
Vol 49 (8) ◽  
pp. 864-872 ◽  
Author(s):  
G Tacconi ◽  
V Baldassarre ◽  
N C Collins ◽  
D Bulgarelli ◽  
A M Stanca ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Marker Assisted Selection ◽  
Powdery Mildew Resistance ◽  
Resistance Locus ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Mildew Resistance ◽  
Barley Cultivars ◽  
Barley Powdery Mildew ◽  
Almost All

Recessive mlo alleles of the barley Mlo gene confer resistance to almost all known isolates of the powdery mildew fungal pathogen targeting barley (Hordeum vulgare). To characterize haplotypes present in the Mlo chromosomal region of cultivated Mlo and mlo barley genotypes, weconducted a polymorphism search in 3 predicted low-copy sequence regions adjacent to the Mlo gene by examining a sample of 4 Mlo and 3 mlo cultivars. Eight single-nucleotide polymorphisms (SNPs) and 1 insertion–deletion (indel) were detected, and easy to use PCR-based markers were developed for typing the SNPs. The PCR markers were used to characterize a collection of 46 Mlo and 25 mlo barley cultivars, identifying 3 distinct mlo-11 haplotypes, 1 mlo-9 haplotype, and 4 Mlo haplotypes. We summarized the haplotype and marker information obtained here and in a previous study to help breeders identify strategies for mlo marker-assisted selection. The ability of the markers to identify mlo-resistant genotypes in segregating populations was demonstrated using 2 resistance-characterized F2 populations derived by 3-way crosses.Key words: barley, powdery mildew resistance, mlo, SNPs, marker-assisted selection.

Characterization of the Powdery Mildew Resistance Gene in Wheat Breeding Line KN0816 and its Evaluation in Marker-Assisted Selection

Plant Disease ◽  
2021 ◽  
Author(s):  
Wenrui Wang ◽  
Huagang He ◽  
Huiming Gao ◽  
Hongxing Xu ◽  
Wenyue Song ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Gene ◽  
Marker Assisted Selection ◽  
Powdery Mildew Resistance ◽  
Wheat Breeding ◽  
Agronomic Performance ◽  
Breeding Line ◽  
Powdery Mildew Resistance Gene ◽  
Mildew Resistance

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease seriously threatening yield and quality of common wheat (Triticum aestivum L., 2n=6x=42, AABBDD). Characterization of resistance genes against powdery mildew is useful in parental selection and for developing disease resistant cultivars. Chinese wheat breeding line KN0816 has superior agronomic performance and resistance to powdery mildew at all growth stages. Genetic analysis using populations of KN0816 crossed with different susceptible parents indicated that a single dominant gene, tentatively designated PmKN0816, conferred seedling resistance to different Bgt isolates. Using a bulked segregant analysis (BSA), PmKN0816 was mapped to the Pm6 interval on chromosome arm 2BL using polymorphic markers linked to the catalogued genes Pm6, Pm52, and Pm64, and flanked by markers CISSR02g-6 and CIT02g-2 both with genetic distances of 0.7 cM. Analysis of closely linked molecular markers indicated that the marker alleles of PmKN0816 differed from those of other powdery mildew resistance genes on 2BL, including Pm6, Pm33, Pm51, Pm64, and PmQ. Based on the genetic and physical locations and response pattern to different Bgt isolates, PmKN0816 is most likely a new powdery mildew resistance gene and confers effective resistance to all the 14 tested Bgt isolates. In view of the elite agronomic performance of KN0816 combined with the resistance, PmKN0816 is expected to become a valuable resistance gene in wheat breeding. To transfer PmKN0816 to different genetic backgrounds using marker-assisted selection (MAS), closely linked markers of PmKN0816 were evaluated and four of them (CIT02g-2, CISSR02g-6, CIT02g-10, and CIT02g-17) were confirmed to be applicable for MAS in different genetic backgrounds.

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 mapping of PmSE5785, a new recessive powdery mildew resistance locus, in synthetic hexaploid wheat

Euphytica ◽  
2015 ◽  
Vol 207 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Yajuan Wang ◽  
Changyou Wang ◽  
Wei Quan ◽  
Xiujuan Jia ◽  
Ying Fu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Hexaploid Wheat ◽  
Powdery Mildew Resistance ◽  
Synthetic Hexaploid Wheat ◽  
Resistance Locus ◽  
Mildew Resistance ◽  
Synthetic Hexaploid

scholarly journals Selections from barley landrace collected in Libya as new sources of effective resistance to powdery mildew (Blumeria graminis f.sp. hordei)

2011 ◽  
Vol 48 (No. 5) ◽  
pp. 217-223 ◽  
Author(s):  
J.H. Czembor ◽  
H.J. Czembor
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Agricultural Research ◽  
Genetic Resistance ◽  
Recessive Gene ◽  
Blumeria Graminis ◽  
Hordeum Vulgare L ◽  
Mildew Resistance ◽  
Barley Landrace ◽  
Barley Powdery Mildew

Powdery mildew on barley (Hordeum vulgare L.) caused by the pathogen Blumeria graminis f.sp. hordei occurs worldwide and can result in severe yield loss. Because agronomical methods to control the disease are not completely effective, cultivars with genetic resistance are needed. Therefore, there is a need to describe new sources of genes that confer resistance to barley powdery mildew. This study was conducted to determine the genetic basis of resistance to powdery mildew in three selections 995-1-1, 995-1-2, 995-1-3 from barley landrace 995 (ICB 112840) collected in Al Aziziyah district, Tripolitania, Libya. Landrace originated from InternationalCenter for Agricultural Research in the Dry Areas – ICARDA, Aleppo, Syria. To determine the number of genes, the types of genes action and the gene loci in tested lines two types of crosses were made: (1) the lines were crossed to the susceptible cultivar Pallas, (2) the lines were crossed with Pallas isoline P22 carrying gene mlo5. The parents and progeny F2 were evaluated with isolate R303.1 for the powdery mildew resistance. Based on segregation ratios we found that resistance in these three selections was determined by a single recessive gene allelic to the Mlo locus occurring in Pallas isoline P22. In addition tested lines showed resistance reaction type 0(4) characteristic only for genes mlo. The value of new identified sources of highly effective powdery mildew resistance to breeding programs and barley production is discussed.

scholarly journals Mapping Powdery Mildew Resistance Gene pmYBL on Chromosome 7B of Chinese Wheat (Triticum aestivum L.) Landrace Youbailan

Plant Disease ◽  
2020 ◽  
Vol 104 (9) ◽  
pp. 2411-2417
Author(s):  
Xiaodan Xu ◽  
Wei Liu ◽  
Zhiyong Liu ◽  
Jieru Fan ◽  
Yilin Zhou
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Recessive Gene ◽  
Triticum Aestivum L ◽  
Genetic Distances ◽  
Genomic Region ◽  
Snp Markers ◽  
Single Nucleotide ◽  
Mildew Resistance ◽  
Chinese Wheat

Chinese wheat landrace Youbailan has excellent resistance to powdery mildew caused by Blumeria graminis f. sp. tritici. In the present study, genetic analysis indicated that a recessive gene, tentatively designated pmYBL, was responsible for the powdery mildew resistance of Youbailan. pmYBL was located in the 695-to-715-Mb genomic region of chromosome 7BL, with 19 gene-linked single-nucleotide polymorphism (SNP) markers. It was flanked by SNP1-12 and SNP1-2 with genetic distances of 0.6 and 1.8 centimorgans, respectively. The disease reaction patterns of Youbailan and four cultivars (lines) carrying the powdery mildew (Pm) genes located on chromosome arm 7BL indicated that pmYBL may be allelic or closely linked to these genes. All of the SNP markers linked to pmYBL were diagnostic, indicating that these markers will be useful for pyramiding pmYBL using marker-assisted selection.

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