The transfer of stem rust resistance from the Ethiopian durum wheat St. 464 to common wheat

1996 ◽  
Vol 76 (2) ◽  
pp. 317-319 ◽  
Author(s):  
D. R. Knott

Two genes for stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.) resistance were transferred from the Ethiopian durum wheat (Triticum turgidum L) accession St. 464 to Thatcher and Prelude/8* Marquis common wheat. One gene was shown by monosomic analysis to be on chromosome 4B and proved to be Sr7a. Monosomic analysis failed to locate the second gene. It is only partially dominant and conditions resistance to a range of races. Key words: Rust resistance, stem rust, wheat, Puccinia graminis tritici, Triticum aestivum, Triticum turgidum

2009 ◽  
Vol 89 (6) ◽  
pp. 1003-1008
Author(s):  
D R Knott

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


1974 ◽  
Vol 16 (2) ◽  
pp. 281-284
Author(s):  
A. K. Sanghi ◽  
E. P. Baker

The single genes in the cultivars Morocco and Yalta conditioning resistance to stem rust culture 103-H-2, a somatic hybrid between wheat stem rust (Puccinia graminis tritici) and rye stem rust (P. graminis secalis) which possesses unusual genes for avirulence on wheat, were each located by monosomic analysis on chromosome 3B. They were estimated to be approximately 9 map units apart.


1975 ◽  
Vol 17 (4) ◽  
pp. 667-674 ◽  
Author(s):  
P. L. Dyck ◽  
G. J. Green

The genetics of resistance to stem rust (Puccinia graminis tritici) was investigated in wheat (Triticum aestivum L.) cultivars Romany, Es.P 518/9, Bonny and Tama that are resistant to many races in both Canada and Kenya. Seedling resistance in the four cultivars to 12 Canadian races is controlled primarily by previously identified genes. The results indicate that the cultivars have the following genes: Romany — Sr5, Sr6, Sr7a, Sr9b and SrW; Es.P 518/9 — Sr5, Sr6, Sr7a, Sr8, Sr9b, SrW and possibly Sr17; Bonny — Sr6 and Sr11; and Tama — Sr6 and Sr8. Gene SrW confers moderate resistance and is also present in the cultivar Webster.


Genome ◽  
1993 ◽  
Vol 36 (2) ◽  
pp. 289-293 ◽  
Author(s):  
P. L. Dyck

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.


2005 ◽  
Vol 85 (1) ◽  
pp. 49-57 ◽  
Author(s):  
D. R. Knott ◽  
Dapeng Bai ◽  
Janice Zale

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


Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 932-933 ◽  
Author(s):  
D. R. Knott

A type of dwarfism found in crosses involving the wheat (Triticum aestivum L.) cultivar Webster and a stem rust (Puccinia graminis tritici Erik. &Henn.) susceptible line, LMPG, proved to be due to a dominant gene from cv. Webster and a recessive gene from LMPG. The dominant gene is closely linked to the gene Sr30, which conditions stem rust resistance in cv. Webster and is on chromosome 5D. The dwarf plants have short, dark green, stiff leaves and rarely develop more than two leaves before dying.Key words: dwarfism, Triticum aestivum, Puccinia graminis tritici, stem rust.


Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 405-409 ◽  
Author(s):  
Dapeng Bai ◽  
D. R. Knott

Six accessions of Triticum turgidum var. dicoccoides L. (4x, AABB) of diverse origin were tested with 10 races of leaf rust (Puccinia recondita f.sp. tritici Rob. ex Desm.) and 10 races of stem rust (P. graminis f.sp. tritici Eriks. &Henn.). Their infection type patterns were all different from those of lines carrying the Lr or Sr genes on the A or B genome chromosomes with the same races. The unique reaction patterns are probably controlled by genes for leaf rust or stem rust resistance that have not been previously identified. The six dicoccoides accessions were crossed with leaf rust susceptible RL6089 durum wheat and stem rust susceptible 'Kubanka' durum wheat to determine the inheritance of resistance. They were also crossed in diallel to see whether they carried common genes. Seedlings of F1, F2, and BC1F2 generations from the crosses of the dicoccoides accessions with RL6089 were tested with leaf rust race 15 and those from the crosses with 'Kubanka' were tested with stem rust race 15B-1. The F2 populations from the diallel crosses were tested with both races. The data from the crosses with the susceptible durum wheats showed that resistance to leaf rust race 15 and stem rust race 15B-1 in each of the six dicoccoides accessions is conferred by a single dominant or partially dominant gene. In the diallel crosses, the dominance of resistance appeared to be affected by different genetic backgrounds. With one exception, the accessions carry different resistance genes: CI7181 and PI 197483 carry a common gene for resistance to leaf rust race 15. Thus, wild emmer wheat has considerable genetic diversity for rust resistance and is a promising source of new rust resistance genes for cultivated wheats.Key words: wheat rust, leaf rust, stem rust, rust resistance, genetic diversity.


1970 ◽  
Vol 50 (3) ◽  
pp. 229-232 ◽  
Author(s):  
P. L. DYCK ◽  
G. J. GREEN

The inheritance of resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn.) was investigated in Triticum aestivum L. cv. Red Bobs. It carries a gene for stem rust resistance at the Sr7 locus that resembles Sr7b of Marquis, and a gene that is either Sr10 or, more likely, an allele, because Red Bobs is less resistant than the Marquis-Sr10 line to races C1 (17) and C17 (56).


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