scholarly journals Map-based isolation of disease resistance genes from bread wheat: cloning in a supersize genome

2005 ◽  
Vol 85 (2) ◽  
pp. 93-100 ◽  
Author(s):  
BEAT KELLER ◽  
CATHERINE FEUILLET ◽  
NABILA YAHIAOUI
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Leaf Rust ◽  
Bread Wheat ◽  
Genetic Map ◽  
Resistance Genes ◽  
Positional Cloning ◽  
Repetitive Sequences ◽  
Near Future ◽  
Genome Projects

The genome of bread wheat is hexaploid and contains 1·6×1010 bp of DNA, of which more than 80% is repetitive sequences. Its size and complexity represent a challenge for the isolation of agronomically important genes, for which we frequently know only their position on the genetic map. Recently, new genomic resources and databases from genome projects have simplified the molecular analysis of the wheat genome. The first genes to be isolated from wheat by map-based cloning include three resistance genes against the fungal diseases powdery mildew and leaf rust. In this review, we will describe the approaches and resources that have contributed to this progress, and discuss genomic strategies that will simplify positional cloning in wheat in the near future.

Effectiveness of major resistance genes and identification of new sources for disease resistance in wheat

2011 ◽  
Vol 59 (3) ◽  
pp. 241-248 ◽  
Author(s):  
G. Vida ◽  
M. Cséplő ◽  
G. Gulyás ◽  
I. Karsai ◽  
T. Kiss ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Genetic Material ◽  
Leaf Rust Resistance ◽  
Wheat Varieties ◽  
Major Resistance Genes ◽  
Greenhouse Tests

Among the factors which determine yield reliability an important role is played by disease resistance. One of the breeding aims in the Martonvásár institute is to develop wheat varieties with resistance to major diseases. The winter wheat varieties bred in Martonvásár are examined in artificially inoculated nurseries and greenhouses for resistance to economically important pathogens. The effectiveness of designated genes for resistance to powdery mildew and leaf rust has been monitored over a period of several decades. None of the designated major resistance genes examined in greenhouse tests is able to provide complete resistance to powdery mildew; however, a number of leaf rust resistance genes provide full protection against pathogen attack (Lr9, Lr19, Lr24, Lr25, Lr28 and Lr35). In the course of marker-assisted selection, efficient resistance genes (Lr9, Lr24, Lr25 and Lr29) have been incorporated into Martonvásár wheat varieties. The presence of Lr1, Lr10, Lr26, Lr34 and Lr37 in the Martonvásár gene pool was identified using molecular markers. New sources carrying alien genetic material have been tested for powdery mildew and leaf rust resistance. Valuable Fusarium head blight resistance sources have been identified in populations of old Hungarian wheat varieties. Species causing leaf spots (Pyrenophora tritici-repentis, Septoria tritici and Stagonospora nodorum) have gradually become more frequent over the last two decades. Tests on the resistance of the host plant were begun in Martonvásár four years ago and regular greenhouse tests on seedlings have also been initiated.

Allelism and resistance loci of powdery mildew and leaf rust in Egyptian hexaploid bread wheat

2021 ◽  
Author(s):  
Ibrahim Sobhy Draz ◽  
Ahmed Fawzy Elkot ◽  
Abdelrazek Shaarawy Abdelrhim
Keyword(s):  
Powdery Mildew ◽  
Leaf Rust ◽  
Bread Wheat

scholarly journals Tracking of powdery mildew and leaf rust resistance genes in Triticum boeoticum and T. urartu, wild relatives of common wheat

2011 ◽  
Vol 47 (No. 2) ◽  
pp. 45-57 ◽  
Author(s):  
N.A. Hovhannisyan ◽  
M.E. Dulloo ◽  
A.H. Yesayan ◽  
H. Knüpffer ◽  
A. Amri
Keyword(s):  
Powdery Mildew ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Diploid Species ◽  
Leaf Rust Resistance ◽  
Gene Marker ◽  
Sequence Tagged Sites ◽  
A Genome ◽  
Triticum Boeoticum

Wild Triticum and Aegilops species are increasingly used in wheat breeding programmes around the world as donors of genes conferring resistance to biotic and abiotic stresses, as well as of genes that contribute to the improvement of grain quality. In the present study, thirty-nine accessions of diploid species with the A genome (Triticum boeoticum and T. urartu) were evaluated for the presence of the genes conferring resistance to powdery mildew (Blumeria graminis) and leaf rust (Puccinia recondita) using both inoculation tests and sequence tagged sites (STS) marker analyses in order to find correspondence between STS markers and resistance as a trait. The most resistant entries were T. boeoticum accessions. All the marked Lr and Pm resistance genes (Pm1, Pm2, Pm3, Lr10, Lr47, Lr25 and Lr28) were identified in the check T. aestivum cultivar Bezostaya 1. The resistance to powdery mildew in the material studied was conferred by the combination of the Pm1 gene with either Pm2 or Pm3. The Pm1 and Pm3 markers appeared to be suitable for tracking these powdery mildew resistance genes, while the Pm2 gene marker cannot be considered as usable in various genetically different wheat accessions. The presence of the genes Lr25, Lr28 and Lr47 seems to be particularly useful for obtaining leaf rust resistance in T. boeoticum and T. urartu species.  

scholarly journals The determination of the resistance inheritance against common bunt in wheat and half-diallel hybrids

2019 ◽  
Vol 55 (No. 4) ◽  
pp. 254-260
Author(s):  
Gülçin Akgören Palabiyik ◽  
İsmail Poyraz ◽  
Ahmet Umay
Keyword(s):  
Disease Resistance ◽  
Bread Wheat ◽  
Resistance Genes ◽  
Common Bunt ◽  
Wheat Varieties ◽  
Complete Dominance ◽  
Selection For ◽  
Half Diallel ◽  
Dominant Genes

This study was conducted to determine the inheritance of common bunt resistance in twelve bread wheat varieties and their half-diallel hybrids in Turkey. The disease ratings were performed on the F2 generations of the hybrids in field conditions. The obtained data were analysed by the χ2 test to determine the effective gene numbers and inheritance type in the disease resistance. In addition, the data were evaluated according to the Jinks-Hayman diallel analyses. In conclusion, it was found that of the twelve wheat parents, four contained three resistance genes and four of them contain two resistance genes. The dominant genes were prominent in the population and complete dominance was present. Therefore, the selection for disease resistance should be delayed until the following generations.

Disease resistance in the genusAegilops L. — stem rust, leaf rust, stripe rust, and powdery mildew

1985 ◽  
Vol 33 (2) ◽  
pp. 133-153 ◽  
Author(s):  
Jan Valkoun ◽  
Karl Hammer ◽  
Dagmar Kučerová ◽  
Pavel Bartoš
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Leaf Rust ◽  
Stripe Rust ◽  
Stem Rust

Linkage mapping of powdery mildew and greenbug resistance genes on recombinant 1RS from 'Amigo' and 'Kavkaz' wheat–rye translocations of chromosome 1RS.1AL

Genome ◽  
2004 ◽  
Vol 47 (2) ◽  
pp. 292-298 ◽  
Author(s):  
Yehia Mater ◽  
Stephen Baenziger ◽  
Kulvinder Gill ◽  
Robert Graybosch ◽  
Lynda Whitcher ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Dna Sequences ◽  
Secale Cereale ◽  
Polyacrylamide Gel Electrophoresis ◽  
Rflp Markers ◽  
Resistance Locus ◽  
Greenbug Resistance

Cultivated rye (Secale cereale L., 2n = 2x = 14, RR) is an important source of genes for insect and disease resistance in wheat (Triticum aestivum L., 2n = 6x = 42). Rye chromosome arm 1RS of S. cereale 'Kavkaz' originally found as a 1BL.1RS translocation, carries genes for disease resistance (e.g., Lr26, Sr31, Yr9, and Pm8), while 1RS of the S. cereale 'Amigo' translocation (1RSA) carries a single resistance gene for greenbug (Schizaphis graminum Rondani) biotypes B and C and also carries additional disease-resistance genes. The purpose of this research was to identify individual plants that were recombinant in the homologous region of.1AL.1RSV and 1AL.1RSA using both molecular and phenotypic markers. Secale cereale 'Nekota' (1AL.1RSA) and S. cereale 'Pavon 76' (1AL.1RSV) were mated and the F1 was backcrossed to 'Nekota' (1AL.1AS) to generate eighty BC1F2:3 families (i.e., ('Nekota' 1AL.1RSA × 'Pavon 76' 1AL.1RSV) × 'Nekota' 1AL.1AS). These families were genotyped using the secalin–gliadin grain storage protein banding pattern generated with polyacrylamide gel electrophoresis to discriminate 1AL.1AS/1AL.1RS heterozygotes from the 1AL.1RSA+V and 1AL.1AS homozygotes. Segregation of the secalin locus and PCR markers based on the R173 family of rye specific repeated DNA sequences demonstrated the presence of recombinant 1AL.1RSA+V families. Powdery mildew (Blumeria graminis) and greenbug resistance genes on the recombinant 1RSA+V arm were mapped in relation to the Sec-1 locus, 2 additional protein bands, 3 SSRs, and 13 RFLP markers. The resultant linkage map of 1RS spanned 82.4 cM with marker order and spacing showing reasonable agreement with previous maps of 1RS. Fifteen markers lie within a region of 29.7 cM next to the centromere, yet corresponded to just 36% of the overall map length. The map position of the RFLP marker probe mwg68 was 10.9 cM distal to the Sec-1 locus and 7.8 cM proximal to the powdery mildew resistance locus. The greenbug resistance gene was located 2.7 cM proximal to the Sec-1 locus.Key words: microsatellites, SSRs, RFLP, secalin-gliadin, alien genes introgression.

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