Rust resistance in Triticum cylindricum Ces. (4x, CCDD) and its transfer into durum and hexaploid wheats

Genome ◽  
1995 ◽  
Vol 38 (1) ◽  
pp. 8-16 ◽  
Author(s):  
D. Bai ◽  
G. J. Scoles ◽  
D. R. Knott
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Hexaploid Wheat ◽  
Rust Resistance ◽  
Addition Line ◽  
Addition Lines ◽  
D Genome ◽  
C Genome ◽  
Translocation Lines ◽  
Disomic Addition Lines

In order to counteract the effects of the mutant genes in races of leaf rust (Puccinia recondita f.sp. tritici Rob. ex Desm.) and stem rust (P. graminis f.sp. tritici Eriks. &Henn.) in wheat, exploration of new resistance genes in wheat relatives is necessary. Three accessions of Triticum cylindricum Ces. (4x, CCDD), Acy1, Acy9, and Acy11, were tested with 10 races each of leaf rust and stem rust. They were resistant to all races tested. Viable F1 plants were produced from the crosses of the T. cylindricum accessions as males with susceptible MP and Chinese Spring ph1b hexaploid wheats (T. aestivum, 6x, AABBDD), but not with susceptible Kubanka durum wheat (T. turgidum var. durum, 4x, AABB), even with embryo rescue. In these crosses the D genome of hexaploid wheat may play a critical role in eliminating the barriers for species isolation during hybrid seed development. The T. cylindricum rust resistance was expressed in the F1 hybrids with hexaploid wheat. However, only the cross MP/Acy1 was successfully backcrossed to another susceptible hexaploid wheat, LMPG-6. In the BC2F2 of the cross MP/Acy1//LMPG-6/3/MP, monosomic or disomic addition lines with resistance to either leaf rust race 15 (infection types (IT) 1=, 1, or 1+; addition line 1) or stem rust race 15B-1 (IT 1 or 1+; addition line 2) were selected. Rust tests and examination of chromosome pairing of the F1 hybrids and the progeny of the disomic addition lines confirmed that the genes for rust resistance were located on the added T. cylindricum C-genome chromosomes rather than on the D-genome chromosomes. The T. cylindricum chromosome in addition line 2 was determined to be chromosome 4C through the detection of RFLPs among the genomes using a set of homoeologous group-specific wheat cDNA probes. Addition line 1 was resistant to the 10 races of leaf rust and addition line 2 was resistant to the 10 races of stem rust, as was the T. cylindricum parent. The added C-genome chromosomes occasionally paired with hexaploid wheat chromosomes. Translocation lines with rust resistance (2n = 21 II) may be obtained in the self-pollinated progeny of the addition lines through spontaneous recombination of the C-genome chromosomes and wheat chromosomes. Such translocation lines with resistance against a wide spectrum of rust races should be potentially valuable in breeding wheat for rust resistance.Key words: wheat, Triticum cylindricum, rust resistance, gene transfer, addition line, molecular cytogenetics.

Transfer of leaf rust and stem rust resistance genes from Triticum triaristatum to durum and bread wheats and their molecular cytogenetic localization

Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 410-418 ◽  
Author(s):  
D. Bai ◽  
G. J. Scoles ◽  
D. R. Knott
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Rust Resistance ◽  
Seed Set ◽  
Wide Spectrum ◽  
Embryo Rescue ◽  
Addition Line ◽  
Addition Lines ◽  
The Cross ◽  
Disomic Addition Lines

Six accessions of Triticum triaristatum (Willd) Godr. &Gren. (syn. Aegilops triaristata) (6x, UUMMUnUn), having good resistance to both leaf rust (Puccinia recondita f.sp. tritici Rob. ex Desm) races and stem rust (P. graminis f.sp. tritici Eriks. &Henn.) races, were successfully crossed with both susceptible durum wheats (T. turgidum var. durum L., 2n = 28, AABB) and bread wheats (T. aestivum, 2n = 42, AABBDD). In some crosses, embryo rescue was necessary. The T. triaristatum resistance was expressed in all F1 hybrids. Backcrossing of the F1 hybrids to their wheat parents to produce BC1F1 plants was more difficult (seed set 0–7.14%) than to produce F1 hybrids (seed set 12.50–78.33%). The low female fertility of the F1 hybrids was due to low chromosome pairing. Only gametes with complete or nearly complete genomes from the F1 hybrids were viable. In BC2F4 populations from the cross MP/Ata2//2*MP, monosomic or disomic addition lines (2n = 21 II + 1 I or 22 II) with resistance to leaf rust race 15 (IT 1) were selected. In BC2F2 populations from the crosses CS/Ata4//2*MP and MP/Ata4//2*MP, monosomic or disomic addition lines with resistance to either leaf rust race 15 or stem rust race 15B-1 (both IT 1) were selected. Rust tests and cytology on the progeny of the disomic addition lines confirmed that the genes for rust resistance were located on the added T. triaristatum chromosomes. The homoeologous groups of the T. triaristatum chromosomes in the addition lines from the crosses MP/Ata2//2*MP, CS/Ata4//2*MP, and MP/Ata4//2*MP were determined to be 5, 2, and 7, respectively, through the detecting of RFLPs among genomes using a set of homoeologous group specific wheat cDNA probes. The addition lines with resistance to leaf rust race 15 from the crosses MP/Ata2//2*MP and CS/Ata4//2*MP were resistant to another nine races of leaf rust and the addition line with resistance to stem rust race 15B-1 from the cross MP/Ata4//2*MP was resistant to another nine races of stem rust as were their T. triaristatum parents. Since such genes provide resistance against a wide spectrum of rust races they should be very valuable in wheat breeding for rust resistance.Key words: Triticum triaristatum, rust resistance, addition line, molecular cytogenetics.

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

Suppression of rust resistance in bread wheat (Triticum aestivum L.) by D-genome chromosomes

Genome ◽  
1992 ◽  
Vol 35 (2) ◽  
pp. 276-282 ◽  
Author(s):  
D. Bai ◽  
D. R. Knott
Keyword(s):  
Triticum Aestivum ◽  
Leaf Rust ◽  
Bread Wheat ◽  
Stem Rust ◽  
Chinese Spring ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
D Genome ◽  
Or Genes

Several tests were done in bread wheat (Triticum aestivum L.) to demonstrate the occurrence of genes on D-genome chromosomes that suppress resistance to leaf rust (Puccinia recondita f. sp. tritici Rob. ex Desm.) and stem rust (Puccinia graminis f. sp. tritici Eriks. &Henn.). Ten rust-resistant wild tetraploid wheats (T. turgidum var. dicoccoides) were crossed with both durum (T. turgidum var. durum) and bread wheats. In all cases, resistance to leaf rust and stem rust was expressed in the hybrids with durum wheats but suppressed in the hybrids with bread wheats. Crosses were made between five diverse durum wheats and four diverse bread wheats. The pentaploid hybrid seedlings of 12 crosses were tested with leaf rust race 15 and in all cases the resistance of the durum parents was suppressed. Fourteen D-genome disomic chromosome substitution lines in the durum wheat 'Langdon' were tested with stem rust race 15B-1 and leaf rust race 15. Chromosomes 1B, 2B, and 7B were found to carry genes for resistance to stem rust but no suppressors were detected. Chromosomes 2B and 4B carried genes for resistance to leaf rust, and 1D and 3D carried suppressors. Crosses between seven D-genome monosomies of 'Chinese Spring' and three dicoccoides accessions showed that 'Chinese Spring' possesses genes on 1D, 2D, and 4D, which suppress the stem rust resistance of all three dicoccoides accessions. All three chromosomes must be present to suppress resistance, indicating that some form of complementary gene interaction is involved. In addition, 'Chinese Spring' carries a gene or genes on 3D that suppresses the leaf rust resistance of all three dicoccoides accessions, plus a gene or genes on 1D that suppresses the leaf rust resistance of only one of them. The data raise some interesting questions about the specificity of the suppressors. The high frequency of occurrence of suppressors in the bread wheat population suggests that they must have a selective advantage.Key words: Triticum aestivum, stem rust, leaf rust, rust resistance, suppressor.

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.

Disomic Thinopyrum intermedium addition lines in wheat with barley yellow dwarf virus resistance and with rust resistances

Genome ◽  
1995 ◽  
Vol 38 (2) ◽  
pp. 385-394 ◽  
Author(s):  
P. J. Larkin ◽  
P. M. Banks ◽  
E. S. Lagudah ◽  
R. Appels ◽  
Chen Xiao ◽  
...  
Keyword(s):  
Stripe Rust ◽  
Stem Rust ◽  
Rust Resistance ◽  
Barley Yellow Dwarf Virus ◽  
Yellow Dwarf ◽  
Addition Lines ◽  
Thinopyrum Intermedium ◽  
Barley Yellow Dwarf ◽  
Group 2 ◽  
Yellow Dwarf Virus

Zhong 5 is a partial amphiploid (2n = 56) between Triticum aestivum (2n = 42) and Thinopyrum intermedium (2n = 42) carrying all the chromosomes of wheat and seven pairs of chromosomes from Th. intermedium. Following further backcrossing to wheat, six independent stable 2n = 44 lines were obtained representing 4 disomic chromosome addition lines. One chromosome confers barley yellow dwarf virus (BYDV) resistance, whereas two other chromosomes carry leaf and stem rust resistance; one of the latter also confers stripe rust resistance. Using RFLP and isozyme markers we have shown that the extra chromosome in the Zhong 5-derived BYDV resistant disomic addition lines (Z1, Z2, or Z6) belongs to the homoeologous group 2. It therefore carries a different locus to the BYDV resistant group 7 addition, L1, described previously. The leaf, stem, and stripe rust resistant line (Z4) carries an added group 7 chromosome. The line Z3 has neither BYDV nor rust resistance, is not a group 2 or group 7 addition, and is probably a group 1 addition. The line Z5 is leaf and stem rust resistant, is not stripe rust resistant, and its homoeology remains unknown.Key words: Agropyron, intermediate wheatgrass, leaf rust, stem rust, stripe rust, luteovirus.

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.

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.

Seedling resistances to rust diseases in international triticale germplasm

2010 ◽  
Vol 61 (12) ◽  
pp. 1036 ◽  
Author(s):  
J. Zhang ◽  
C. R. Wellings ◽  
R. A. McIntosh ◽  
R. F. Park
Keyword(s):  
Leaf Rust ◽  
Stripe Rust ◽  
Plant Resistance ◽  
Stem Rust ◽  
Rust Resistance ◽  
Adult Plant Resistance ◽  
Stem Rust Resistance ◽  
Adult Plant ◽  
Seedling Resistance ◽  
Rust Diseases

Seedling resistances to stem rust, leaf rust and stripe rust were evaluated in the 37th International Triticale Screening Nursery, distributed by the International Wheat and Maize Improvement Centre (CIMMYT) in 2005. In stem rust tests, 12 and 69 of a total of 81 entries were postulated to carry Sr27 and SrSatu, respectively. When compared with previous studies of CIMMYT triticale nurseries distributed from 1980 to 1986 and 1991 to 1993, the results suggest a lack of expansion in the diversity of stem rust resistance. A total of 62 of 64 entries were resistant to five leaf rust pathotypes. In stripe rust tests, ~93% of the lines were postulated to carry Yr9 alone or in combination with other genes. The absence of Lr26 in these entries indicated that Yr9 and Lr26 are not genetically associated in triticale. A high proportion of nursery entries (63%) were postulated to carry an uncharacterised gene, YrJackie. The 13 lines resistant to stripe rust and the 62 entries resistant to leaf rust represent potentially useful sources of seedling resistance in developing new triticale cultivars. Field rust tests are needed to verify if seedling susceptible entries also carry adult plant resistance.

The transfer of leaf rust resistance from Triticum turgidum ssp. dicoccoides to hexaploid wheat

1994 ◽  
Vol 74 (4) ◽  
pp. 671-673 ◽  
Author(s):  
P. L. Dyck
Keyword(s):  
Genetic Diversity ◽  
Genetic Analysis ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Hexaploid Wheat ◽  
Rust Resistance ◽  
Triticum Turgidum ◽  
Leaf Rust Resistance ◽  
Rust Resistance Gene ◽  
Leaf Rust Resistance Gene

Accession 8404 of Triticum turgidum ssp. dicoccoides was shown to have excellent resistance to leaf rust. Genetic analysis of the F3 of 8404 and RL6089, a leaf rust susceptible durum, indicated that 8404 had three genes for leaf rust resistance. Two of these genes were transferred to hexaploid wheat (Thatcher) by a series of backcrosses. One of the genes transferred was the same as Lr33 (RL6057). The second gene, which gives a fleck reaction to avirulent P. recondita races, appears to be fully incorporated into the hexaploid where it segregated to fit a one-gene ratio. Backcross lines with this gene give excellent resistance to leaf rust, although race MBG is virulent to this gene. This may be a previously unidentified leaf rust resistance gene and should increase the genetic diversity available for wheat breeders. Key words:Triticum aestivum, wheat, Triticum turgidum ssp. dicoccoides, leaf rust resistance

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