Identification of stem rust and leaf rust resistance genes in Amagalon oats

2001 ◽  
Vol 52 (10) ◽  
pp. 1011 ◽  
Author(s):  
K. N. Adhikari ◽  
R. A. McIntosh
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Rust Resistance ◽  
Recessive Gene ◽  
Leaf Rust Resistance ◽  
Leaf Rust Resistance Gene ◽  
Breeding Programs ◽  
Sensitivity Tests ◽  
Unique Source ◽  
Leaf Rust Resistance Genes

Studies were undertaken to identify the genes conferring stem rust and leaf rust resistances in Amagalon and to determine the usefulness of this line as a source of rust resistance in oat breeding programs. Amagalon was crossed with certain rust-resistant and rust-susceptible lines and segregating populations were tested with pathotypes of Puccinia graminis avenae and P. coronata avenae. Tests with the widely virulent P. graminis avenae pt 94+Pg-13 indicated that resistance in Amagalon was governed by the complementary recessive gene complex known as Pg-a. This hypothesis was further substantiated by temperature sensitivity tests and by a test of induced susceptibility to stem rust, known to be unique to lines possessing Pg-a. However, Amagalon yielded a unique source of resistance to leaf rust that was effective against current pathotypes of P. coronata avenae in Australia. This gene, assumed to be Pc91, was inherited independently of a second leaf rust resistance gene present in cv. Culgoa. It was concluded that Amagalon is a useful source of resistance to leaf rust that should be used in combination with other genes for resistance to prolong its effectiveness.

Resistance to wheat leaf rust and stem rust in Triticum tauschii and inheritance in hexaploid wheat of resistance transferred from T. tauschii

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 813-822 ◽  
Author(s):  
R. L. Innes ◽  
E. R. Kerber
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Adult Plant ◽  
Seedling Resistance ◽  
Triticum Tauschii ◽  
Synthetic Hexaploids ◽  
Seedling Leaf ◽  
Leaf Rust Resistance Genes

Twelve accessions of Triticum tauschii (Coss.) Schmal. were genetically analyzed for resistance to leaf rust (Puccinia recondita Rob. ex Desm.) and stem rust (Puccinia graminis Pers. f.sp. tritici Eriks. and E. Henn.) of common wheat (Triticum aestivum L.). Four genes conferring seedling resistance to leaf rust, one gene conferring seedling resistance to stem rust, and one gene conferring adult-plant resistance to stem rust were identified. These genes were genetically distinct from genes previously transferred to common wheat from T. tauschii and conferred resistance to a broad spectrum of pathogen races. Two of the four seedling leaf rust resistance genes were not expressed in synthetic hexaploids, produced by combining tetraploid wheat with the resistant T. tauschii accessions, probably owing to the action of one or more intergenomic suppressor loci on the A or B genome. The other two seedling leaf rust resistance genes were expressed at the hexaploid level as effectively as in the source diploids. One gene was mapped to the short arm of chromosome 2D more than 50 cM from the centromere and the other was mapped to chromosome 5D. Suppression of seedling resistance to leaf rust in synthetic hexaploids derived from three accessions of T. tauschii allowed the detection of three different genes conferring adult-plant resistance to a broad spectrum of leaf rust races. The gene for seedling resistance to stem rust was mapped to chromosome ID. The degree of expression of this gene at the hexaploid level was dependent on the genetic background in which it occurred and on environmental conditions. The expression of the adult-plant gene for resistance to stem rust was slightly diminished in hexaploids. The production of synthetic hexaploids was determined to be the most efficient and flexible method for transferring genes from T. tauschii to T. aestivum, but crossing success was determined by the genotypes of both parents. Although more laborious, the direct introgression method of crossing hexaploid wheat with T. tauschii has the advantages of enabling selection for maximum expression of resistance in the background hexaploid genotype and gene transfer into an agronomically superior cultivar.Key words: Triticum tauschii, rust resistance, gene expression, gene transfer, wheat, synthetic hexaploid.

scholarly journals Performance and Mapping of Leaf Rust Resistance Transferred to Wheat from Triticum timopheevii subsp. armeniacum

2003 ◽  
Vol 93 (7) ◽  
pp. 784-789 ◽  
Author(s):  
G. L. Brown-Guedira ◽  
S. Singh ◽  
A. K. Fritz
Keyword(s):  
Microsatellite Markers ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Germ Plasm ◽  
Leaf Rust Resistance ◽  
Leaf Rust Resistance Gene ◽  
Rust Resistance Genes ◽  
Leaf Rust Resistance Genes

Host plant resistance is an economical and environmentally sound method of control of leaf rust caused by the fungus Puccinia triticina, which is one of the most serious diseases of wheat (Triticum aestivum) worldwide. Wild relatives of wheat, including the tetraploid T. timopheevii subsp. armeniacum, represent an important source of genes for resistance to leaf rust. The objectives of this study were to (i) evaluate the performance of leaf rust resistance genes previously transferred to wheat from three accessions of T. timopheevii subsp. armeniacum, (ii) determine inheritance and allelic relationship of the new leaf rust resistance genes, and (iii) determine the genetic map location of one of the T. timopheevii subsp. armeniacum-derived genes using microsatellite markers. The leaf rust resistance gene transferred to hexaploid wheat from accession TA 28 of T. timopheevii subsp. armeniacum exhibited slightly different infection types (ITs) to diverse races of leaf rust in inoculated tests of seedlings compared with the gene transferred from TA 870 and TA 874. High ITs were exhibited when seedlings of all the germ plasm lines were inoculated with P. triticina races MBRL and PNMQ. However, low ITs were observed on adult plants of all lines having the T. timopheevii subsp. armeniacum-derived genes for resistance in the field at locations in Kansas and Texas. Analysis of crosses between resistant germ plasm lines showed that accessions TA 870 and TA 874 donated the same gene for resistance to leaf rust and TA 28 donated an independent resistance gene. The gene donated to germ plasm line KS96WGRC36 from TA 870 of T. timopheevii subsp. armeniacum was linked to microsatellite markers Xgwm382 (6.7 cM) and Xgdm87 (9.4 cM) on wheat chromosome arm 2B long. This new leaf rust resistance gene is designated Lr50. It is the first named gene for leaf rust resistance transferred from wild timopheevi wheat and is the only Lr gene located on the long arm of wheat homoeologous group 2 chromosomes.

scholarly journals Leaf Rust Resistance Gene Lr34 Associated with Nonsuppression of Stem Rust Resistance in the Wheat Cultivar Canthatch

1999 ◽  
Vol 89 (6) ◽  
pp. 518-521 ◽  
Author(s):  
E. R. Kerber ◽  
T. Aung
Keyword(s):  
Leaf Rust ◽  
Resistance Gene ◽  
Stem Rust ◽  
Chinese Spring ◽  
Rust Resistance ◽  
Wheat Cultivar ◽  
Leaf Rust Resistance ◽  
Stem Rust Resistance ◽  
Rust Resistance Gene ◽  
Leaf Rust Resistance Gene

The common wheat cultivar Thatcher and the backcross derivative Canthatch are moderately or fully susceptible to several races of stem rust because of a suppressor on chromosome 7DL that inhibits the expression of the relevant resistance gene(s). The incorporation of leaf rust resistance gene Lr34 into ‘Thatcher’ is known to enhance stem rust resistance. The effect of this gene in a ‘Canthatch’ background and its relationship with the 7DL suppressor were determined by replacing chromosome 7D of ‘Canthatch’ with 7D of ‘Chinese Spring’, which possesses Lr34 on the short arm. ‘Canthatch’ nullisomic 7D was crossed with ‘Chinese Spring’, followed by a succession of backcrosses to the nullisomic recurrent parent. Homozygous resistant disomic and monosomic substitution lines were recovered that exhibited the same resistant reaction as that of ‘Thatcher’ possessing Lr34 and as that of ‘Canthatch’ nullisomic 7D, in which the 7DL suppressor is absent. The results indicate that, in ‘Canthatch’, Lr34 permits expression of resistance genes normally inhibited by the 7DL suppressor. Furthermore, it is likely that, in ‘Thatcher’ and ‘Thatcher’ back-cross derivatives, Lr34 inactivates the 7DL suppressor.

scholarly journals Chromosomal Location and Genetic Relationship of Leaf Rust Resistance Genes Rph9 and Rph12 in Barley

1998 ◽  
Vol 88 (1) ◽  
pp. 76-80 ◽  
Author(s):  
I. G. Borovkova ◽  
Y. Jin ◽  
B. J. Steffenson
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Chromosomal Location ◽  
Leaf Rust Resistance ◽  
Chromosome 7 ◽  
Puccinia Hordei ◽  
Leaf Rust Resistance Gene ◽  
Rust Resistance Genes ◽  
Leaf Rust Resistance Genes

Barley lines Hor 2596 and Triumph are the sources of leaf rust resistance genes Rph9 and Rph12, respectively. An allelism test was performed with F2 progeny of the cross Triumph/Hor 2596 inoculated with Puccinia hordei. No recombinants were found in a population of 3,858 progeny, indicating Rph9 and Rph12 are alleles. Molecular and morphological markers were used to identify the chromosomal location of these genes in the crosses Bowman/Hor 2596 and Triumph/I91-533-va. A linkage was detected between Rph9 and the flanking sequence-tagged site (STS) markers ABC155 and ABG3 on chromosome 7(5H) at a distance of 20.6 and 20.1 centimorgans (cM), respectively, and to the microsatellite marker dehydrin-9 (HVDHN9) at a distance of 10.2 cM in the Bowman/ Hor 2596 cross. Analysis of isozymes in bulks of the same population showed that Rph9 may be closely linked to the Est9 locus on chromosome 7(5H). The Rph12 locus was linked to the morphological trait locus va (controlling variegated leaf color) on chromosome 7(5H) at a distance of 22.6 cM in the Triumph/I91-533-va cross. Rph12 also was linked with STS marker ABC155 (24.4 cM) and RAPD marker OPA19 (1.5) (17.8 cM). These data indicate that Hor 2596 and Triumph carry a leaf rust resistance gene at the same locus on the long arm of chromosome 7(5H) of barley.

Race and Virulence Analysis of Puccinia triticina in China in 2014 and 2015

Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 455-464 ◽  
Author(s):  
Lin Zhang ◽  
Congcong Shi ◽  
Lingrui Li ◽  
Min Li ◽  
Qingfang Meng ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Breeding Programs ◽  
Single Leaf ◽  
Rust Resistance Genes ◽  
Race Analysis ◽  
Leaf Rust Resistance Genes

Wheat leaf rust, caused by Puccinia triticina, is an important fungal disease of wheat in China. To study races of the pathogen in China, leaf rust samples were collected from 14 provinces in 2014 and 15 provinces in 2015. From the samples, 494 single-uredinial isolates were derived from the 2014 collection and 649 from the 2015 collection. These isolates were tested on 40 near-isogenic lines of Thatcher carrying single leaf rust resistance genes. From the isolates, 84 races were identified in 2014 and 65 races in 2015. Races THTT (22.1%), THTS (19.6%), THJT (8.7%), PHTT (4.9%), and PHJT (3.6%) were the most common races in 2014, and THTT (28.4%), THTS (12.8%), THJT (11.6%), THJS (9.9%), and PHTT (9.7%) were the most frequent in 2015. All of these races were avirulent to resistance genes Lr9 and Lr24. THTT and THTS, the most frequent races in both years, were widely distributed throughout the country. The frequencies of isolates with virulence to Lr1, Lr2a, Lr2c, Lr3, Lr16, Lr26, Lr11, Lr17, LrB, Lr10, Lr14a, Lr2b, Lr3bg, Lr14b, Lr32, Lr33, and Lr50 were over 80%, whereas the frequencies of virulence to Lr9, Lr19, Lr25, Lr28, Lr29, and Lr47 were less than 3.5%. In the present study, all isolates were avirulent to Lr24 and Lr38. The race analysis and individual virulence frequencies provide guidance to breeders in choosing leaf rust resistance genes for use in breeding programs.

scholarly journals Race and Virulence Analysis of Puccinia triticina in China During 2011 to 2013

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2095-2101
Author(s):  
Lin Zhang ◽  
Yu Xiao ◽  
Ying Gao ◽  
Na Zhao ◽  
Yajuan An ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Leaf Rust Resistance Gene ◽  
Breeding Programs ◽  
Single Leaf ◽  
The Individual ◽  
Selection Of

Wheat leaf rust, caused by Puccinia triticina, is a common fungal disease of wheat in China. In order to identify races and determine the individual virulence of isolates in different wheat-growing regions in China, leaf rust samples collected from 18 provinces in 2011 to 2013 were tested on 37 Thatcher near-isogenic lines each carrying a different single leaf rust resistance gene. A total of 158 races were identified. Races THTT (19.5%), THTS (16.9%), PHTT (7.7%), THJS (5.0%), THJT (4.2%), and PHTS (4.0%) were the most predominant races in 2011 to 2013. All of these races were avirulent to resistance genes Lr9 and Lr24. The two most frequent races, THTT and THTS, were widely distributed. The frequencies of the isolates with virulence to Lr1, Lr2c, Lr3, Lr16, Lr26, Lr17, LrB, Lr10, Lr14a, Lr3bg, Lr14b, Lr33, Lr37, and Lr50 exceeded 90%. Frequencies of virulence to Lr2a, Lr3ka, Lr11, Lr30, Lr2b, and Lr32 exceeded 70% but were less than 90%. Frequencies of virulence to Lr18, Lr21, Lr15, Lr23, Lr33+34, Lr36, Lr39, and Lr44 were below 70%, whereas the frequency of virulence to Lr25 was less than 1%. All isolates were avirulent to Lr9, Lr19, Lr24, Lr28, Lr42, Lr29, Lr38, and Lr47. The identified races and individual virulence frequencies provide a basis for selection of effective leaf rust resistance genes for use in breeding programs and can also provide information for the study of race evolution of P. triticina.

scholarly journals Map-Based Cloning of Leaf Rust Resistance Gene Lr21 From the Large and Polyploid Genome of Bread Wheat

Genetics ◽  
2003 ◽  
Vol 164 (2) ◽  
pp. 655-664 ◽  
Author(s):  
Li Huang ◽  
Steven A Brooks ◽  
Wanlong Li ◽  
John P Fellers ◽  
Harold N Trick ◽  
...  
Keyword(s):  
Amino Acid ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Bread Wheat ◽  
Rust Resistance ◽  
Agronomic Traits ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Rust Resistance Gene ◽  
Leaf Rust Resistance Gene

Abstract We report the map-based cloning of the leaf rust resistance gene Lr21, previously mapped to a generich region at the distal end of chromosome arm 1DS of bread wheat (Triticum aestivum L.). Molecular cloning of Lr21 was facilitated by diploid/polyploid shuttle mapping strategy. Cloning of Lr21 was confirmed by genetic transformation and by a stably inherited resistance phenotype in transgenic plants. Lr21 spans 4318 bp and encodes a 1080-amino-acid protein containing a conserved nucleotide-binding site (NBS) domain, 13 imperfect leucine-rich repeats (LRRs), and a unique 151-amino-acid sequence missing from known NBS-LRR proteins at the N terminus. Fine-structure genetic analysis at the Lr21 locus detected a noncrossover (recombination without exchange of flanking markers) within a 1415-bp region resulting from either a gene conversion tract of at least 191 bp or a double crossover. The successful map-based cloning approach as demonstrated here now opens the door for cloning of many crop-specific agronomic traits located in the gene-rich regions of bread wheat.

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