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.

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.

scholarly journals Cytogenetic analysis and mapping of leaf rust resistance in Aegilops speltoides Tausch derived bread wheat line Selection2427 carrying putative gametocidal gene(s)

Genome ◽  
2017 ◽  
Vol 60 (12) ◽  
pp. 1076-1085 ◽  
Author(s):  
M. Niranjana ◽  
Vinod ◽  
J.B. Sharma ◽  
Niharika Mallick ◽  
S.M.S. Tomar ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Bread Wheat ◽  
Rust Resistance ◽  
Dominant Gene ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Aegilops Speltoides ◽  
Lr Genes ◽  
Gametocidal Gene ◽  
Chromosome 3B

Leaf rust (Puccinia triticina) is a major biotic stress affecting wheat yields worldwide. Host-plant resistance is the best method for controlling leaf rust. Aegilops speltoides is a good source of resistance against wheat rusts. To date, five Lr genes, Lr28, Lr35, Lr36, Lr47, and Lr51, have been transferred from Ae. speltoides to bread wheat. In Selection2427, a bread wheat introgresed line with Ae. speltoides as the donor parent, a dominant gene for leaf rust resistance was mapped to the long arm of chromosome 3B (LrS2427). None of the Lr genes introgressed from Ae. speltoides have been mapped to chromosome 3B. Since none of the designated seedling leaf rust resistance genes have been located on chromosome 3B, LrS2427 seems to be a novel gene. Selection2427 showed a unique property typical of gametocidal genes, that when crossed to other bread wheat cultivars, the F1 showed partial pollen sterility and poor seed setting, whilst Selection2427 showed reasonable male and female fertility. Accidental co-transfer of gametocidal genes with LrS2427 may have occurred in Selection2427. Though LrS2427 did not show any segregation distortion and assorted independently of putative gametocidal gene(s), its utilization will be difficult due to the selfish behavior of gametocidal genes.

THE INHERITANCE OF LEAF RUST RESISTANCE IN SEVEN VARIETIES OF COMMON WHEAT

1961 ◽  
Vol 41 (2) ◽  
pp. 342-359 ◽  
Author(s):  
R. G. Anderson
Keyword(s):  
Leaf Rust ◽  
Common Wheat ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Susceptible Variety ◽  
The Other ◽  
Seedling Resistance ◽  
Genetic Studies ◽  
Type Reaction ◽  
Biological Studies

The inheritance of seedling resistance to races 1a, 5a, 11, 15a and 126a of leaf rust was studied in the varieties Exchange and Selkirk and to races 1a and 15a in the varieties Lee, Gabo, Timstein, Mayo 52 and Mayo 54. Thatcher was used as the susceptible variety. Rust tests were carried out on F1 and F2 populations of diallel crosses among these varieties and on F2 families from the backcrosses to Thatcher. Two genes were found. One gene LrE conditions a (2) type reaction to all five races in Exchange and Selkirk. The other gene LrL conditions a (; 1 =) type reaction to races 1a and 15a in all seven varieties. Isogenic lines possessing these genes are being developed in the varieties Prelude and Thatcher. The importance of such lines in future genetic studies and their application in other biological studies are discussed.The increase in amount of leaf rust found on Lee and Selkirk in Canada during the period 1951–1958 is accounted for by the increase of races which render the gene LrL ineffective in these two varieties.

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.

Transfer to hexaploid wheat of linked genes for adult-plant leaf rust and seedling stem rust resistance from an amphiploid of Aegilops speltoides × Triticum monococcum

Genome ◽  
1990 ◽  
Vol 33 (4) ◽  
pp. 530-537 ◽  
Author(s):  
E. R. Kerber ◽  
P. L. Dyck
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Dominant Gene ◽  
Leaf Rust Resistance ◽  
Stem Rust Resistance ◽  
Adult Plant ◽  
Aegilops Speltoides ◽  
Plant Leaf

A partially dominant gene for adult-plant leaf rust resistance together with a linked, partially dominant gene for stem rust resistance were transferred to the hexaploid wheat cultivar 'Marquis' from an amphiploid of Aegilops speltoides × Triticum monococcum by direct crossing and backcrossing. Pathological evidence indicated that the alien resistance genes were derived from Ae. speltoides. Differential transmission of the resistance genes through the male gametes occurred in hexaploid hybrids involving the resistant 'Marquis' stock and resulted in distorted segregation ratios. In heterozygotes, pairing between the chromosome arm with the alien segment and the corresponding arm of the normal wheat chromosome was greatly reduced. The apparent close linkage between the two resistance genes, 3 ± 1.07 crossover units, was misleading because of this decrease in pairing in the presence of the 5B diploidizing mechanism. The newly identified gene for adult-plant leaf rust resistance, located on chromosome 2B, is different from adult-plant resistance genes Lr12, Lr13, and Lr22 and from that in the hexaploid accession PI250413; it has been designated Lr35. It is not known whether the newly transferred gene for stem rust resistance differs from Sr32, also derived from Ae. speltoides and located on chromosomes 2B.Key words: hexaploid, Triticum, Aegilops, aneuploid, Puccinia graminis, Puccinia recondita.

scholarly journals Genetic analysis and molecular mapping of leaf rust resistance genes in the wheat line 5R618

2014 ◽  
Vol 50 (No. 4) ◽  
pp. 262-267 ◽  
Author(s):  
J. Wang ◽  
L. Shi ◽  
L. Zhu ◽  
X. Li ◽  
D. Liu
Keyword(s):  
Leaf Rust ◽  
Resistance Gene ◽  
Rust Resistance ◽  
Molecular Mapping ◽  
Dominant Gene ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Rust Resistance Gene ◽  
Leaf Rust Resistance Gene

The wheat (Triticum aestivum L.) line 5R618, bred at the China Agricultural University, is resistant in the seedling stage to the majority of the current Chinese pathotypes of wheat leaf rust (Puccinia triticina). To identify and map the leaf rust resistance gene in the 5R618 line, F<sub>2</sub> plants and F<sub>2:3</sub> families from a cross between 5R618 and Zhengzhou5389 (susceptible) were inoculated in the greenhouse with the Chinese P. triticina pathotype THJP. Results from the F<sub>2</sub> and F<sub>2:3</sub> populations indicate that a single dominant gene, temporarily designated&nbsp;Lr5R, conferred resistance. Using the molecular marker method, Lr5R was located on the 3DL chromosome. It was closely linked to the markers Xbarc71 and OPJ-09 with genetic distances of 0.9 cM and 1.0 cM, respectively. At present only one designated gene (Lr24) is located on the 3DL chromosome. The genetic distance between Lr5R&nbsp;and Lr24 confirms that Lr5R is a new leaf rust resistance gene.

scholarly journals The recognition of an alien chromosome segment translocated to a wheat chromosome

1967 ◽  
Vol 10 (3) ◽  
pp. 295-301 ◽  
Author(s):  
G. Kimber
Keyword(s):  
Leaf Rust ◽  
Rust Resistance ◽  
Wheat Variety ◽  
Wheat Chromosome ◽  
Leaf Rust Resistance ◽  
Chromosome Segment ◽  
Interference Microscopy ◽  
Alien Chromosome ◽  
Small Segment

1. Chromosome 6B of T. aestivum, to which a small segment of an Ae. umbellulata chromosome had been translocated, was examined both by interference microscopy and in stained preparations.2. In the stained preparation a constriction was observed in the long arm of chromosome 6B and also a terminal knob that was also observed on chromosome A of Ae. umbellulata.3. These features were also observed by interference microscopy and in addition the portion of the chromosome 6B of Transfer distal to the constriction had different phase-retarding properties.4. It is concluded that the part of chromosome 6B distal to the constriction is the part of Ae. umbellulata chromosome A which carries the gene for the leaf-rust resistance of that species and of the wheat variety into which it was translocated.

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