The association of a gene for leaf rust resistance with the chromosome 7D suppressor of stem rust resistance in common wheat

Genome ◽  
1987 ◽  
Vol 29 (3) ◽  
pp. 467-469 ◽  
Author(s):  
P. L. Dyck
Keyword(s):  
Leaf Rust ◽  
Common Wheat ◽  
Stem Rust ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Suppressor Gene ◽  
Stem Rust Resistance ◽  
Recurrent Parent ◽  
Cytogenetic Evidence

Backcross lines of gene LrT2 for resistance to leaf rust in the common wheat (Triticum aestivum L.) 'Thatcher' unexpectedly show improved resistance to stem rust compared with that of the recurrent parent. Genetic–cytogenetic evidence indicates that LrT2 is on chromosome 7D, which is known to carry the "suppressor" gene(s) that prevent the expression of stem rust resistance conferred by other genes in 'Canthatch'. Thus, LrT2 may be a nonsuppressing allele of the suppressor gene(s) or be closely linked to such an allele. LrT2 has been designated Lr34. Key words: Triticum, wheat, rust resistance.

Inheritance of leaf rust and stem rust resistance in 'Roblin' wheat

Genome ◽  
1993 ◽  
Vol 36 (2) ◽  
pp. 289-293 ◽  
Author(s):  
P. L. Dyck
Keyword(s):  
Triticum Aestivum ◽  
Leaf Rust ◽  
Stem Rust ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Susceptible Cultivar ◽  
Wheat Leaf

The Canadian common wheat (Triticum aestivum L.) cultivar 'Roblin' is resistant to both leaf rust (Puccinia recondita Rob. ex. Desm.) and stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn.). To study the genetics of this resistance, 'Roblin' was crossed with 'Thatcher', a leaf rust susceptible cultivar, and RL6071, a stem rust susceptible line. A set of F6 random lines was developed from each cross. The random lines and the parents were grown in a field rust nursery artificially inoculated with a mixture of P. recondita and P. graminis isolates and scored for rust reaction. The same material was tested with specific races of leaf rust and stem rust. These data indicated that 'Roblin' has Lr1, Lr10, Lr13, and Lr34 for resistance to P. recondita and Sr5, Sr9b, Sr11, and possibly Sr7a and Sr12 for resistance to P. graminis. In a 'Thatcher' background, the presence of Lr34 contributes to improve stem rust resistance, which appears also to occur in 'Roblin'.Key words: Triticum aestivum, wheat, leaf rust resistance, stem rust resistance.

Linkage and expression of genes for resistance to leaf rust and stem rust in triticale

Genome ◽  
1990 ◽  
Vol 33 (1) ◽  
pp. 115-118 ◽  
Author(s):  
S. J. Singh ◽  
R. A. McIntosh
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Genetic Linkage ◽  
Rust Resistance ◽  
Single Gene ◽  
Leaf Rust Resistance ◽  
Stem Rust Resistance ◽  
Stem Rust Resistance Gene ◽  
Expression Of Genes ◽  
Triticosecale Wittmack

Leaf rust resistance in five triticale cultivars was controlled by a single gene designated LrSatu. This gene was closely linked in coupling with the stem rust resistance gene SrSatu believed to be located on chromosome 3R. Approximately 50% of lines in the 17th International Triticale Screening Nursery possessed SrSatu and LrSatu. Lines carrying SrSatu and LrSatu occurred more frequently among complete than in substituted triticale lines.Key words: × Triticosecale Wittmack, P. graminis f.sp. tritici, P. recondita f.sp. tritici, leaf rust, stem rust, rust resistnace, genetic linkage.

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.

ANEUPLOID ANALYSIS OF A GENE FOR LEAF RUST RESISTANCE DERIVED FROM THE COMMON WHEAT CULTIVAR TERENZIO

1981 ◽  
Vol 23 (3) ◽  
pp. 405-409 ◽  
Author(s):  
P. L. Dyck ◽  
E. R. Kerber
Keyword(s):  
Leaf Rust ◽  
Common Wheat ◽  
Rust Resistance ◽  
Wheat Cultivar ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Backcross Line ◽  
The Common ◽  
Aneuploid Analysis ◽  
Leaf Rust Resistance Genes

The LrT gene for resistance to leaf rust present in the common wheat (Triticum aestivum L.) backcross line RL 6049, and originally derived from the cultivar Terenzio, was shown to be on chromosome 4B. Farther analysis indicated that it is on the long arm of this chromosome, 2.9 ± 1.3 crossover units from the centromere. It is independent of or loosely linked with Sr7a, a gene for stem rust resistance known to be on the long arm of chromosome 4B. It is inherited independently of leaf rust resistance genes Lr1, Lr2a, Lr3, Lr10, Lr14b, Lr16, Lr17 and Lr18. LrT has been redesignated Lr30.

The transfer of leaf and stem rust resistance from wild emmer wheats to durum and common wheat

2005 ◽  
Vol 85 (1) ◽  
pp. 49-57 ◽  
Author(s):  
D. R. Knott ◽  
Dapeng Bai ◽  
Janice Zale
Keyword(s):  
Leaf Rust ◽  
Common Wheat ◽  
Stem Rust ◽  
Hexaploid Wheat ◽  
Rust Resistance ◽  
Triticum Turgidum ◽  
Wheat Breeding ◽  
Stem Rust Resistance ◽  
Emmer Wheat ◽  
Wild Emmer

Wild emmer wheats (Triticum turgidum var. dicoccoides L.) are potentially valuable sources of leaf rust (Puccinia triticina Eriks.) and stem rust (Puccinia graminis f. sp. tritici Eriks. & Henn.) resistance in breeding both durum (T. turgidum var. durum L.) and common wheat (T. aestivum L.). In an extension of previous work, 11 rust resistant accessions of wild emmer wheat were crossed and backcrossed from two to five times to susceptible durum or common wheats. Genes for leaf or stem rust resistance were transferred singly into several susceptible genotypes. Backcross lines homozygous for resistance to leaf rust were tested with a set of either 9 or 10 leaf rust races and those homozygous for resistance to stem rust were tested with a set of either 10 or 13 stem rust races. The emmer wheats proved to carry a number of genes for resistance to each rust. In most cases, when a cross was made to a hexaploid wheat, resistance to both rusts was suppressed in the F1 seedlings, even when resistance was dominant in the tetraploids. Nevertheless, resistance was successfully transferred from several accessions to the hexaploids, indicating that suppressors on the A or B genome chromosomes were involved and segregation occurred for them. Rust resistance tended to decrease when it was transferred to another species, particularly hexaploid wheat. A number of lines carrying genes for either leaf rust or stem rust resistance were resistant to all races with which they were tested and have potential in wheat breeding. Key words: Emmer wheat, Triticum turgidum var. dicoccoides, stem rust, leaf rust, suppressors

AGRONOMIC AND QUALITY CHARACTERISTICS OF WHEAT LINES WITH LEAF RUST RESISTANCE DERIVED FROM TRITICUM SPELTOIDES

1981 ◽  
Vol 23 (3) ◽  
pp. 475-480 ◽  
Author(s):  
D. R. Knott ◽  
J. Dvořák
Keyword(s):  
Leaf Rust ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Quality Characteristics ◽  
Puccinia Recondita ◽  
Recurrent Parent ◽  
Wheat Lines ◽  
Speltoides Chromosome ◽  
Deleterious Genes

Eleven lines of wheat (Triticum aestivum L.) carrying resistance to leaf rust (Puccinia recondita Rob. ex. Desm.) derived from five accessions of Triticum speltoides Tausch were grown in yield tests in 1977 and 1979. The grain was tested for quality characteristics in both years. Although the lines had been backcrossed four or five times to either Manitou or Neepawa, only four of the eleven showed any real promise of equalling their recurrent parent in agronomic and quality characteristics. Lines derived from the same accession of T. speltoides were surprisingly variable. The generally deleterious effects of the transferred chromatin are due either to genes linked to the genes for leaf rust resistance plus incomplete compensation by the speltoides chromosome segment for the aestivum segment it replaced, or to the effects of additional translocations that were not eliminated during backcrossing. A second cycle of homoeologous recombination is proposed as a way to eliminate some of the deleterious genes.

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.

Genes for stem rust resistance in Thatcher wheat

2009 ◽  
Vol 89 (6) ◽  
pp. 1003-1008
Author(s):  
D R Knott
Keyword(s):  
Triticum Aestivum ◽  
Common Wheat ◽  
Stem Rust ◽  
Rust Resistance ◽  
Triticum Aestivum L ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Genetic Studies ◽  
Number Of Genes ◽  
The Common

The common wheat (Triticum aestivum L.) cultivar Thatcher has resistance to many of the older races of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.). Several genetic studies have shown that its resistance is complex in inheritance. To attempt to clarify the inheritance, 28 lines, each believed to carry a single resistance gene from Thatcher, were developed. The lines were tested with 13 races of stem rust. They fell into 13 types with resistance to from 1 to 11 races. Of the five genes previously identified in Thatcher, only two, Sr9g, and Sr12, were present in the lines. Four lines carried named genes, Sr6, Sr7a, Sr8a and S9d, which had not previously been detected in Thatcher. Thatcher is resistant to 8 of the 13 races. At least one line was resistant to each of the 13 races, including the five to which Thatcher is susceptible. Eleven of the 13 types of lines were resistant to race MCCD to which Thatcher is resistant. Seven of the types were resistant to race TMRT(15B-1) to which Thatcher is susceptible. Clearly, the inheritance of resistance in Thatcher is very complex and involves a considerable number of genes. It carries a surprising number of genes that appear to be hidden by the presence of suppressor genes or transposons.Key words: Common wheat, Triticum aestivum, Puccinia graminis, suppressors, tansposons

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