The inheritance of resistance to race 56 of stem rust in 'Marquillo' wheat

1984 ◽  
Vol 26 (2) ◽  
pp. 174-176 ◽  
Author(s):  
D. R. Knott

The common wheat (Triticum aestivum L.) cultivar 'Marquillo' was crossed and backcrossed to 'Marquis,' and was also crossed with the 'Chinese Spring' monosomics. Seedlings from the F2 families from the backcross and from F2 and F3 families from the crosses with the monosomics were tested with race 56 of stem rust (Puccinia graminis tritici Eriks. and Henn.). The results indicated that 'Marquillo' carries a single recessive gene for resistance to race 56, located on chromosome 3B. The gene which was identified as Sr12, appears to be temperature sensitive and was affected by a recessive modifier.Key words: wheat, Triticum aestivum, Puccinia graminis, monosomics, rust resistance.

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


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.


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.


1997 ◽  
Vol 77 (2) ◽  
pp. 289-292
Author(s):  
D. R. Knott

The wheat (Triticum aestivum L.) cultivars Bonza and Chris have adult plant resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.) in addition to genes for specific resistance. Both cultivars were crossed to a susceptible wheat, LMPG. Lines carrying the adult plant resistances of the two parents were produced by selecting for seedling susceptibility in the greenhouse and adult plant resistance in the field to race 15B-1 (TMH). Three homozygous lines derived from Bonza and two from Chris were crossed and backcrossed to LMPG. Backcross F2 families were grown in a field nursery inoculated with a multi-race mixture of eight stem rust isolates including 15B-1. Stem rust severities in percent were recorded. An analysis of the data indicated that adult plant resistance of Bonza was controlled by a single recessive gene and that of Chris by two complementary recessive genes. Since the resistance was effective against a complex mixture of virulent stem rust races, it should be of interest to wheat breeders. Key words: Stem rust, Puccinia graminis, common wheat, Triticum aestivum, adult plant resistance


Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 854-856
Author(s):  
D. R. Knott

The inheritance of stem rust (Puccinia graminis f. sp. tritici Eriks. and Henn.) resistance was studied in 'K253', a hexaploid wheat (Triticum aestivum L.) with resistance derived from a tetraploid wheat (T. turgidum L.). The studies indicated that 'K253' carries one dominant gene for good resistance to races 29 and 56 (probably Sr9e) and one recessive gene for moderate resistance to race 15B-1. In addition, some plants apparently carry a recessive gene for moderate resistance to race 56. Four different types of hexaploid near-isogenic lines were produced. One carried Sr9e and another the gene for moderate resistance to race 15B-1. Two carried genes that had not been identified in the genetic studies, including one that was apparently not derived from K253.Key words: stem rust resistance, Puccinia graminis tritici, wheat, Triticum aestivum, Triticum turgidum.


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).


Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 97-98 ◽  
Author(s):  
D. R. Knott

Four stem rust (Puccinia graminis tritici Eriks. &Henn.) resistant wheat (Triticum aestivum L.) – Agropyron recombinants were analyzed to determine the wheat chromosomes involved. The Agropyron chromosome, 7el2, was known to be homoeologous to the group 7 chromosomes of wheat. Monosomic analysis showed that all four recombinants involved wheat chromosome 7D.Key words: rust resistance, Puccinia, Agropyron, wheat, Triticum, homoeologous recombination.


1977 ◽  
Vol 55 (11) ◽  
pp. 1445-1452 ◽  
Author(s):  
D. J. Samborski ◽  
W. K. Kim ◽  
R. Rohringer ◽  
N. K. Howes ◽  
R. J. Baker

Seedlings of resistant (Sr6) and susceptible (sr6) near-isogenic lines of wheat (Triticum aestivum L.) were inoculated with a race of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) that was avirulent on the line with Sr6 and they were kept at 19, 25, 26, and 27 °C. Fluorescence microscopy was used to detect autofluorescing necrotic host cells and rust colonies after these were stained with a fiuorochrome (Calcofluor White M2R New).In leaves containing the Sr6 gene, a smaller percentage of colonies grown at 25 °C had necrotic cells associated with them than those that were grown at 19 °C. The incidence of colony-associated necrosis in these leaves could be further reduced by increasing the temperature to 26 °C and 27 °C. Similarly, the number of necrotic host cells per colony decreased with an increase in temperature. Colonies in genotypically resistant leaves were usually smaller than those in genotypically susceptible leaves, but the differences in colony sizes between these two lines decreased at the higher temperatures.When infected plants containing the Sr6 gene were kept for varying times at 25 °C and then were transferred to 19 °C, there was significantly less fungal growth and more necrosis than in plants kept continuously at 25 °C. This necrosis occurred largely in those cells that were invaded after the transfer to 19 °C, when the Sr6 gene was activated.


Sign in / Sign up

Export Citation Format

Share Document