GENETICS OF PATHOGENICITY IN THREE RACES OF LEAF RUST ON FOUR WHEAT VARIETIES

1973 ◽  
Vol 15 (1) ◽  
pp. 73-82 ◽  
Author(s):  
M. E. A. Haggag ◽  
D. J. Samborski ◽  
P. L. Dyck
Keyword(s):  
Leaf Rust ◽  
Virulence Genes ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Dominant Allele ◽  
Genetics Of Resistance ◽  
Selfed Progeny ◽  
Wheat Varieties

Populations of self-fertilized cultures of races 9, 11 and 161, "backcross" selfed progeny of race 11, F1 cultures of races 9 × 11 and 11 × 161, and F2 cultures of races 9 × 161 were used to study the genetics of virulence on the wheat varieties Democrat, Sinvalocho, Bage and Klein Aniversario and backcross lines developed from them.Race 9 was homozygous avirulent on all the host varieties tested. Selfed populations of race 11 segregated for a recessive gene, p3, for virulence on Democrat × Thatcher6 (Lr3), Sinvalocho and Sinvalocho × Thatcher2. Race 11 has an additional dominant gene for virulence on the latter two varieties. Race 11 appears to have p3 plus a second gene(s) for virulence or a modifier(s) of the dominant allele of p3 for virulence on Sinvalocho × Prelude6 (Lr3). This would correspond to a modifier or suppressor in the genetics of resistance of Sinvalocho × Prelude6. Race 11 was homozygous for avirulence on Bage, heterozygous for p3 and one other gene for virulence on Bage × Thatcher8. This race was heterozygous for two genes for virulence on Klein Aniversario and for one gene on backcross lines derived from this variety. These genes were independent of p3. The data of the "backcross" selfed progeny of race 11 agreed in general with the above. Race 161 was segregating for a dominant gene for virulence on Democrat, Democrat × Thatcher6 and Sinvalocho × Prelude6, and for a recessive gene on Bage and Klein Aniversario × Thatcher6. It was homozygous avirulent on Klein Aniversario and homozygous virulent on Bage × Thatcher8. The pathogenicity of the F1 cultures of races 11 × 161 suggested that the two races have virulence genes at the same locus. These data and those from the F2 populations of races 9 × 161 supported the results from the selfed populations.

INHERITANCE OF VIRULENCE IN WHEAT LEAF RUST ON THE STANDARD DIFFERENTIAL WHEAT VARIETIES

1968 ◽  
Vol 10 (1) ◽  
pp. 24-32 ◽  
Author(s):  
D. J. Samborski ◽  
P. L. Dyck
Keyword(s):  
Leaf Rust ◽  
Dominant Gene ◽  
Recessive Gene ◽  
The Other ◽  
Wheat Leaf Rust ◽  
Single Recessive Gene ◽  
Wheat Varieties ◽  
Wheat Leaf ◽  
Recessive Genes ◽  
Race 1

Populations of self-fertilized cultures from races 1, 9, 15 and 161 of wheat leaf rust were studied for inheritance of virulence on the eight standard differential wheat varieties. Race 9 was homozygous at all loci tested while the other races segregated at a number of loci. Recessive genes controlled virulence on the varieties Malalkof (gene Lr1) and Hussar (gene Lr11) respectively. Virulence to Mediterranean and Democrat was governed by a single recessive gene in race 1 and a single dominant gene in race 161. One recessive gene in races 1 and 15 governed virulence to the various alleles of the Lr2 locus, while in race 161 a second dominant gene altered the expression of avirulence of this gene on Loros (Lr24). An additional recessive gene for virulence interacted with gene LrB in Carina and Brevit. It is not known whether the gene for virulence, which corresponds to a particular host gene for resistance, is the same in each race of leaf rust that was studied. All genes for virulence segregated independently.

Adult-plant leaf rust resistance in Thatcher and Marquis wheat: a genetic analysis of the host–parasite interaction

1969 ◽  
Vol 47 (2) ◽  
pp. 267-269 ◽  
Author(s):  
P. Bartos ◽  
P. L. Dyck ◽  
D. J. Samborski
Keyword(s):  
Leaf Rust ◽  
Adult Plant Resistance ◽  
Recessive Gene ◽  
Leaf Rust Resistance ◽  
Adult Plant ◽  
Single Recessive Gene ◽  
Wheat Varieties ◽  
Host Parasite ◽  
Host Genes ◽  
Adult Plants

Inheritance of adult-plant resistance to race 9 of leaf rust was investigated in the wheat varieties Thatcher and Marquis. Resistance was conferred by the same recessive gene in both varieties. The genetics of virulence on adult plants of Thatcher was studied in a F2 population of cultures from a cross between races 9 and 161. A single recessive gene conferred virulence on adult plants of Thatcher. This gene was inherited independently of the genes that condition virulence on host genes Lr1, Lr2, Lr3, and Lr11.

scholarly journals Chromosome Location of Mature Plant Leaf Rust Resistance in Chinese Spring Wheat

1966 ◽  
Vol 19 (5) ◽  
pp. 943 ◽  
Author(s):  
RA Mcintosh ◽  
EP Baker
Keyword(s):  
Leaf Rust ◽  
Chinese Spring ◽  
Wheat Cultivar ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Leaf Rust Resistance ◽  
Mature Plant ◽  
Mature Plant Resistance ◽  
Chinese Spring Wheat ◽  
Two Factors

Athwal and Watson (1957) reported that the wheat cultivar Chinese Spring W1806t possessed a single dominant gene for mature plant resistance to leaf rust (Puccinia recondita Rob. ex Desm.) and that this gene was allelic with one of two factors in Uruguay W1064. The second factor in Uruguay, operative in both seedling and mature plant stages, was located on chromosomes 5D(XVIII) (McIntosh, Baker, and Driscoll 1965). Uurau (1950) presented F2 and Fs data for crosses involving certain Chinese Spring monosomic lines with the susceptible cultivar Federation 41. His results were inconclusive in associating resistance with a specific chromosome. The behaviour of the Chinese Spring resistance with regard to dominance has been found to vary in different investigations. In addition to the report of Athwal and Watson, Unrau found that the segregation pattern in crosses with Federation 41 indicated that resistance was governed by a single, incompletely dominant pair. On the other hand, Macindoe (1948) reported that a recessive gene for resistance was involved.

scholarly journals Genetic and Cytogenetic Studies of Stem Rust, Leaf Rust, and Powdery Mildew Resistances in Hope and Related Wheat Cultivars

1967 ◽  
Vol 20 (6) ◽  
pp. 1181 ◽  
Author(s):  
RA Mcintosh ◽  
NH Luig ◽  
EP Baker
Keyword(s):  
Powdery Mildew ◽  
Leaf Rust ◽  
Stem Rust ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Stem Rust Resistance ◽  
Gene Interactions ◽  
Adult Plant ◽  
Wheat Cultivars ◽  
Cytogenetic Studies

Three linked genes responsible for resistance respectively to stem rust, to leaf rust, and to powdery mildew are located on chromosome 7B of Hope wheat. The gene for stem rust resistance, operative in seedling and adult plant stages, is recessive and is designated Br17. The incompletely dominant gene for resistance to leaf rust, designated Lr14, showed 18% recombination with sr17, whilst in two different crosses recombination estimates of 6�0 and 2�5%, respectively, were obtained for the recessive gene for mildew resistance and Br17. All three genes were found to be present in a high proportion of Hope and H�44 derivatives. The gene Br 1'7 is apparently ineffective in conferring resistance to North American and pre.1954 Australian stem rust strains. Its incorporation into several cultivars selected for resistance to these strains presumably resulted from gene interactions or linkage with genes for resistance to other diseases.

GENETICS OF RESISTANCE TO LEAF RUST IN THE COMMON WHEAT VARIETIES WEBSTER, LOROS, BREVIT, CARINA, MALAKOF AND CENTENARIO

1968 ◽  
Vol 10 (1) ◽  
pp. 7-17 ◽  
Author(s):  
P. L. Dyck ◽  
D. J. Samborski
Keyword(s):  
Leaf Rust ◽  
Common Wheat ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Genetics Of Resistance ◽  
Wheat Varieties ◽  
Seedling Resistance ◽  
The Common

Inheritance of seedling resistance to races 15 and 161 of leaf rust was investigated in the varieties Webster, Loros, Brevit, Carina, Malakof and Centenario. Backcross lines were developed in Thatcher and/or Prelude with leaf rust resistance derived from all the varieties except Brevit. The varieties and backcross lines were tested with nine races of rust. Webster was found to have the Lr2 gene which accounts for all of its resistance to the races used. Carina has an allele, Lr22, at the Lr2 locus, plus a gene tentatively assigned the symbol LrB, independent of the Lr2 locus which confers a type 2 reaction to races 15, 161 and probably several others. Resistance present in Loros is accounted for another allele, Lr24, at the Lr2 locus. Brevit also has an allele at the Lr2 locus which may be the same as that in Loros. In addition it probably has gene LrB conferring a type 2 reaction. Gene Lr1, which was independent of the Lr2 locus, accounts for all the detected resistance in Malakof. Centenario has the Lr1 gene and in addition has resistance to races 5 and 126a.The susceptible parents Thatcher and Prelude influence the dominance of the Lr2 alleles. The Lr22 allele in Carina x Prelude6 was partially dominant in crosses with Thatcher and completely dominant in crosses with Red Bobs. The Lr24 allele in Loros x Prelude6 was recessive in crosses with Thatcher and completely dominant in crosses with Prelude and Red Bobs.The expression of resistance of the Lr2 alleles to race 161 in Webster and Carina was different in crosses with Red Bobs than in those with Thatcher. In the crosses with Red Bobs one or more genes, which modified the degree of resistance to race 161, appeared to be segregating. This was not observed in crosses with Thatcher.

INHERITANCE OF VIRULENCE IN PUCCINIA RECONDITA ON ALLELES AT THE Lr2 LOCUS FOR RESISTANCE IN WHEAT

1974 ◽  
Vol 16 (2) ◽  
pp. 323-332 ◽  
Author(s):  
P. L. Dyck ◽  
D. J. Samborski
Keyword(s):  
Leaf Rust ◽  
Rust Fungus ◽  
Recessive Gene ◽  
Puccinia Recondita ◽  
Single Recessive Gene ◽  
Wheat Varieties ◽  
Additional Gene

The inheritance of virulence on the Lr2 alleles for resistance to the leaf rust fungus (P. recondita Rob. ex. Desm.) was investigated using selfed and "backcross" selfed cultures of race 11, F1 cultures of race 9 × race 11, race 11 × race 161 and F1 and F2 cultures of race 9 × race 161. The three host alleles Lr2a, Lr2b and Lr2c were transferred into the wheat varieties Thatcher, Red Bobs and Prelude by a series of backcrosses. Race 11, and probably race 161, have a single recessive gene, p2, for virulence on the three Lr2 alleles and an additional gene(s) that modifies or inhibits the action of the p2 gene on the three host alleles. Lines with the Lr2a gene from Webster were most resistant to the greatest number of cultures, those with Lr2b from Carina were intermediate while those with Lr2c from Brevit and Loros were least resistant. The Lr2 alleles were most effective in the Thatcher background, intermediate in Prelude and least effective in Red Bobs.

THE GENETICS OF TWO ALLELES FOR LEAF RUST RESISTANCE AT THE LR14 LOCUS IN WHEAT

1970 ◽  
Vol 12 (4) ◽  
pp. 689-694 ◽  
Author(s):  
P. L. Dyck ◽  
D. J. Samborski
Keyword(s):  
Leaf Rust ◽  
Rust Resistance ◽  
Dominant Gene ◽  
Wheat Variety ◽  
Recessive Gene ◽  
Leaf Rust Resistance ◽  
The Other ◽  
Single Line

Two genes conferring a similar mesothetic reaction to different races of leaf rust were backcrossed into the wheat variety Thatcher. One of the genes came from Selkirk and the other from Maria Escobar and Bowie. The two genes are alleles at the Lr14 locus, but have been combined into a single line. The inheritance of pathogenicity on these two alleles was studied by using an F2 population of 150 cultures from a cross between races 9 and 161 of leaf rust. Virulence on Lr14a was conferred by a recessive gene and on Lr14b by a dominant gene. These genes for virulence are independently inherited.

scholarly journals Inheritance of Adult Plant Leaf Rust Resistance in the Brazilian Wheat Cultivar Toropi

Plant Disease ◽  
2000 ◽  
Vol 84 (1) ◽  
pp. 90-93 ◽  
Author(s):  
A. L. Barcellos ◽  
A. P. Roelfs ◽  
M. I. B. de Moraes-Fernandes
Keyword(s):  
Leaf Rust ◽  
Plant Resistance ◽  
Rust Resistance ◽  
Adult Plant Resistance ◽  
Wheat Cultivar ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Leaf Rust Resistance ◽  
Adult Plant ◽  
Recessive Genes

Adult plant resistance to leaf rust in the Brazilian wheat cultivar Toropi (Triticum aestivum) was studied in crosses with the susceptible cultivar IAC 13. Cvs. Toropi and IAC 13 are susceptible at the seedling stage to race LCG-RS of Puccinia triticina Erikss., and to all other known Brazilian leaf-rust races. Thus, the resistance observed in Toropi in the field was due to adult plant-resistance genes. In the greenhouse at the adult plant stage, resistance segregated in a 7:9 ratio for two complementary recessive genes. Additionally, two recessive genes for leaf-tip necrosis were identified in the greenhouse environment. Necrosis was expressed when the two homozygous recessive genes occurred together in the F2, independently of the response to leaf rust. The resistance and leaf-necrosis genes differ from those previously reported in wheat. Segregation for leaf-rust resistance in the field at Passo Fundo, Brazil, fit a 1:3 ratio for a single recessive gene. With a different pathogen race, and in crosses of cvs. Toropi and ThatcherLr34, two recessive genes and a dominant gene for resistance were detected in the field in Mexico. The dominant gene was likely Lr34 from cv. ThatcherLr34 and the two recessive genes were likely those detected in the greenhouse adult plants tests at Passo Fundo.

GENETICS OF RESISTANCE TO LEAF RUST IN TWO ACCESSIONS OF COMMON WHEAT

1989 ◽  
Vol 69 (2) ◽  
pp. 531-534 ◽  
Author(s):  
P. L. DYCK ◽  
P. E. JEDEL
Keyword(s):  
Triticum Aestivum ◽  
Leaf Rust ◽  
Rust Resistance ◽  
Infection Type ◽  
Dominant Gene ◽  
Leaf Rust Resistance ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
Genetics Of Resistance ◽  
Wheat Leaf

Two accessions, V336 and V618, of the A. E. Watkins wheat (Triticum aestivum) collection were studied genetically for their resistance to leaf rust (Puccinia recondita). The two accessions have in common a dominant gene that gives a fleck infection type reaction to all the isolates of leaf rust used. This gene may be a previously unidentified gene and we have tentatively assigned the gene symbol LrW. Both accessions also have gene Lr33 and V336 has LrB.Key words: Triticum aestivum, wheat, leaf rust resistance

scholarly journals Genes Governing Resistance to Puccinia hordei in Thirteen Spring Barley Accessions

2000 ◽  
Vol 90 (10) ◽  
pp. 1131-1136 ◽  
Author(s):  
W. S. Brooks ◽  
C. A. Griffey ◽  
B. J. Steffenson ◽  
H. E. Vivar
Keyword(s):  
Leaf Rust ◽  
Resistance Gene ◽  
Rust Resistance ◽  
Spring Barley ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Leaf Rust Resistance ◽  
Puccinia Hordei ◽  
Preliminary Evaluation ◽  
Sources Of Resistance

Leaf rust, caused by Puccinia hordei, is an important disease of barley in many parts of the world. In the eastern United States, this disease was effectively controlled for over 20 years through the deployment of cultivars carrying the resistance gene Rph7. Isolates of P. hordei with virulence for Rph7 appeared in this region in the early 1990s rendering barley cultivars with this gene vulnerable to leaf rust infection. From a preliminary evaluation test, 13 accessions from diverse geographic locations possessed resistance to P. hordei isolate VA90-34, which has virulence for genes Rph1, 2, 4, 6, 7, 8, and 11. Each of these 13 accessions was crossed with susceptible cvs. Moore or Larker to characterize gene number and gene action for resistance to P. hordei. Additionally, the 13 accessions were intercrossed and crossed to host differential lines possessing genes Rph3, Rph5, and Rph9 to determine allelic relationships of resistance genes. Seedlings of F1, F2, and BC1F1 populations were evaluated in the greenhouse for their reaction to P. hordei isolate VA90-34. Leaf rust resistance in six of the accessions including Collo sib, CR270.3.2, Deir Alla 105, Giza 119, Gloria, and Lenka is governed by a single dominant gene located at or near the Rph3 locus. All accessions for which the gene Rph3 was postulated to govern leaf rust resistance, except for Deir Alla 105, likely possess an allele different than Rph3.c found in Estate based on the differential reaction to isolates of P. hordei. The resistance gene in Grit and Donan is located at or near the Rph9 locus. Alleles at both the Rph3 and Rph9 loci confer resistance in Femina and Dorina. In addition to Rph3, Caroline and CR366.13.2 likely possess a second unknown recessive gene for leaf rust resistance. Resistance in Carre 180 is governed by a recessive gene that is different from all other genes considered in this study. Identification of both known and unique genes conferring leaf rust resistance in the barley germplasm included in this study provides breeding programs with the knowledge and opportunity to assess currently used sources of leaf rust resistance and to incorporate new sources of resistance into their programs.

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