THE INHERITANCE OF RUST RESISTANCE: IX. THE INHERITANCE OF RESISTANCE TO RACES 15B AND 56 OF STEM RUST IN THE WHEAT VARIETY KHAPSTEIN

1962 ◽  
Vol 42 (3) ◽  
pp. 415-419 ◽  
Author(s):  
D. R. Knott

The inheritance of resistance to races 15B and 56 of stem rust was studied in the variety Khapstein which obtained its resistance from Khapli emmer. Khapstein was found to carry gene Sr7 which controls resistance to race 15B and two additional genes, one conditioning a type 2 reaction to race 56 and a 2+ – 3 reaction to race 15B, and a second controlling a striking, grey necrosis around pustules produced by race 56. The two have been designated Sr13 and Sr14 respectively.

1959 ◽  
Vol 39 (3) ◽  
pp. 316-328 ◽  
Author(s):  
E. O. Kenaschuk ◽  
R. G. Anderson ◽  
D. R. Knott

The inheritance of resistance to race 15B of stem rust was studied in the varieties St. 464, C.I. 7805, Amarai bianco tipo 142 (P.I. 192179), Arabian, Camadi Abdu tipo 103, Rojal de Almeria (P.I. 191194), C.I. 7870, C.I. 7875, C.I. 8133 and Golden Ball. Rust tests were conducted on F2 plants from diallel crosses and on F2 families from back-crosses to the susceptible varieties, Stewart and Nugget. The following genes are present in the varieties:1. Srd2 conditioning a type 1-X reaction and present in St. 464, C.I. 7805, P.I. 192179, C.I. 7870, C.I. 7875 and C.I. 8133.2. Srd4 conditioning a type 2–2+ reaction and present in Arabian, P.I. 191194 and Golden Ball.3. Srd5 conditioning a type 2 reaction and present in the same varieties as Srd2, plus Arabian.4. Srd6 conditioning a type 1−–1 reaction in Camadi.Two of the genes, Srd2 and Srd5, are additive in effect and together condition a type O; to 1− reaction.


1957 ◽  
Vol 37 (4) ◽  
pp. 366-384 ◽  
Author(s):  
D. R. Knott

The inheritance of resistance to races 15B and 56 of stem rust was studied in the varieties Kenya 58, Kenya 117A, Kenya C9906, Kenya 338.AC.2.E.2, Kenya Governor, Kenya B286, Kenya 291.J.1.I.1, Kenya 321.BT.1.B.1 and Kenya 350.AD.9.C.2. The first five varieties had been studied previously and crosses involving them were not repeated. The genetic analysis of the varieties was based on diallel crosses and backcrosses to a susceptible parent, Marquis.All nine varieties proved to carry Sr7, a gene which conditions resistance to race 15B. Four varieties, Kenya 58, Kenya C9906, Kenya 291 and Kenya 350, carry the gene Sr6, which conditions a hypersensitive reaction to both race 15B and race 56. In addition, four of the varieties carry Sr9 and five carry Sr10, two genes which produce moderate resistance to race 56. Kenya 338.AC.2.E.2 carries two additional dominant, complementary genes, Sr11 and Sr12, which condition resistance to race 56.The genes, Sr9, Sr10, Sr11 and Sr12 are important modifiers of the resistance to race 15B conditioned by Sr7, with Sr9 probably having the greatest effect.


1961 ◽  
Vol 41 (3) ◽  
pp. 587-601 ◽  
Author(s):  
D. R. Knott ◽  
I-Sun Shen

In an attempt to locate new genes for stem rust resistance, 11 varieties of wheat of as diverse origins as possible were studied. Each variety was backcrossed to the susceptible parent Marquis. The F2 families from the backcrosses were tested with races 15B and 56, and the inheritance of resistance determined. The genes carried by each variety were identified from the results of test crosses with varieties carrying known genes and with lines of Marquis carrying single genes for resistance. Most of the resistance present in the 11 varieties could be accounted for on the basis of known genes (Sr6 – Sr10). However, at least one new gene conditioning moderate resistance to race 15B, and possibly one or more new genes conditioning moderate resistance to race 56, were identified.


1957 ◽  
Vol 37 (3) ◽  
pp. 177-192 ◽  
Author(s):  
D. R. Knott

The inheritance of resistance to races 15B and 56 of stem rust was studied in the varieties Africa No. 43, Kenya C9906, Kenya 338.AC.2.E.2, Egypt Na101, Veadeiro and Red Egyptian type (P.I. 170910). Each variety was analysed genetically on the basis of data obtained from a backcross to the rust susceptible variety Marquis. The interrelationships of the genes in the varieties were determined from diallel crosses. With the exception of Veadeiro, the varieties all carried various combinations of genes reported in the first paper of this series. Veadeiro has a mature plant resistance to race 15B which is probably conditioned by two additive genes not previously noted.


1961 ◽  
Vol 41 (1) ◽  
pp. 109-123 ◽  
Author(s):  
D. R. Knott

The rust resistance of a 56-chromosome wheat-Agropyron derivative was found to be controlled by a gene or genes on a single Agropyron chromosome. Resistant wheat plants having 21II of wheat chromosomes plus a single added Agropyron chromosome were produced. Spikes of these plants were irradiated with either gamma rays or X-rays and seeds were irradiated with thermal neutrons. As a result of the irradiation, in at least five lines and possibly seven a piece of the Agropyron chromosome carrying the gene or genes for rust resistance was transferred to a wheat chromosome. One of the translocations is transmitted normally through the gametes but the remaining six show irregularities in transmission particularly through the pollen.


2000 ◽  
Vol 80 (1) ◽  
pp. 53-63 ◽  
Author(s):  
D. R. Knott

Thatcher was the predominant wheat (Triticum aestivum L.) cultivar on the Canadian prairies in the 1950s. Until race 15B (TMH) of stem rust (Puccinia graminis pers. f. sp. tritici Eriks. & Henn.) became widespread, Thatcher had good resistance to stem rust, but was susceptible to leaf rust (P. recondita f. sp. tritici Rob. ex Desm.). Although genes for stem rust resistance have been identified in Thatcher, the inheritance of its resistance has never been fully understood. The objective of this research was to attempt to elucidate the inheritance of the resistance of Thatcher and to determine why it had a reputation as a poor parent for rust resistance. Over a period of 40 yr, crosses and backcrosses to a susceptible genotype and two sets of single seed descent (SSD) lines were studied. The second set of SSD lines was tested with isolates of six races of stem rust to which Thatcher is resistant. The data showed that Thatcher is a very heterogenous cultivar with individual plants differing widely in the genes for stem rust resistance that they carry. The inheritance of rust resistance varied greatly from race to race and was often quite complex. Either complementary genes or a gene plus a suppressor appeared to condition resistance to one race. Most genes gave resistance to only one race. The presence of Sr5, which Thatcher is known to have obtained from Kanred, was confirmed. Most of its many additional genes probably came from Iumillo durum wheat. Key words: Stem rust, Thatcher wheat, single seed descent


2021 ◽  
Vol 12 ◽  
Author(s):  
Hongna Li ◽  
Lei Hua ◽  
Matthew N. Rouse ◽  
Tianya Li ◽  
Shuyong Pang ◽  
...  

Wheat stem (or black) rust is one of the most devastating fungal diseases, threatening global wheat production. Identification, mapping, and deployment of effective resistance genes are critical to addressing this challenge. In this study, we mapped and characterized one stem rust resistance (Sr) gene from the tetraploid durum wheat variety Kronos (temporary designation SrKN). This gene was mapped on the long arm of chromosome 2B and confers resistance to multiple virulent Pgt races, such as TRTTF and BCCBC. Using a large mapping population (3,366 gametes), we mapped SrKN within a 0.29 cM region flanked by the sequenced-based markers pku4856F2R2 and pku4917F3R3, which corresponds to 5.6- and 7.2-Mb regions in the Svevo and Chinese Spring reference genomes, respectively. Both regions include a cluster of nucleotide binding leucine-repeat (NLR) genes that likely includes the candidate gene. An allelism test failed to detect recombination between SrKN and the previously mapped Sr9e gene. This result, together with the similar seedling resistance responses and resistance profiles, suggested that SrKN and Sr9e may represent the same gene. We introgressed SrKN into common wheat and developed completely linked markers to accelerate its deployment in the wheat breeding programs. SrKN can be a valuable component of transgenic cassettes or gene pyramids that includes multiple resistance genes to control this devastating disease.


1967 ◽  
Vol 18 (2) ◽  
pp. 213
Author(s):  
M Ataullah

The inheritance of resistance to stem rust in four durum wheats, namely P.I.168921, P.I.173401, Gaza, and C.I.7809 was studied. The variety P.I.168921 was found to possess two dominant genes Srt1 and Srt5, P.I.173401 two recessive genes srt6 and srt7, Gaza two dominant genes Srt8 and Srt9, and C.I.7809 genes Srt33 and Srt10, for resistance to Australian strains of Puccinia graminis tritici Erikss. & Henn. It was observed that the genes srt6, srt7, Srt9, and Srt10 were independent of genes already identified. Varieties Khapli, St.464, C.I.7778, and P.I.168921 had gene Srt1Srt1 in common; and varieties St.464, C.I.7778, and C.I.7809 gene Srt3 in common.


1960 ◽  
Vol 40 (3) ◽  
pp. 524-538 ◽  
Author(s):  
G. J. Green ◽  
D. R. Knott ◽  
I. A. Watson ◽  
A. T. Pugsley

Lines of the wheat variety Marquis carrying genes Sr6, Sr7, Sr8, Sr9, Sr10, and Sr6 plus Sr7 for resistance to stem rust were produced by the backcross method. The reactions of these lines to 99 North American cultures of 29 races of stem rust and to 8 Australian cultures were determined. Genes Sr6, Sr8, and Sr9 conferred a uniform type of resistance to most of the cultures. Genes Sr7 and Sr10 conferred only moderate resistance to a few cultures. Genes Sr6, Sr8, and Sr9 appeared to confer the same kind of resistance in Marquis after 5 backcrosses as in the source varieties, but Sr7 and Sr10 seemed less effective. Results of the infection studies indicated that Sr7 may be allelic with a gene for resistance in Marquis and that at least two alleles conditioning different rust reactions may occur at the Sr9 locus. The reactions of the lines with Sr6, Sr8, and Sr9 were nearly identical with those of the Chinese Spring substitution lines, Red Egyptian XX, Red Egyptian VI, and Red Egyptian XIII respectively, which presumably have these genes. The data indicated that Sr6 is the same as SrKa1 and Sr9 is the same as SrKb1. The resistance of lines with Sr7, Sr8, and Sr9 was affected only slightly by temperature but the resistance of lines with Sr10 and especially of those with Sr6 diminished at high temperature.


1995 ◽  
Vol 75 (4) ◽  
pp. 781-788 ◽  
Author(s):  
S. L. Fox ◽  
D. E. Harder

Twenty-two barley (Hordeum vulgare L.) cultivars and lines were evaluated for resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.) race QCC in field trials over a 3-yr period, and the inheritance of resistance of several genotypes to race QCC was investigated using replicated F3 lines. Rust severities ranged from 17 to 58% between 14 different cultivars and lines which carried the stem rust resistance gene Rpg1, indicating that factors other than Rpg1 conferred resistance. Hietpas-5 (Rpg2) had moderate resistance while PI 382313 (Rpg3) had good resistance to race QCC. In the cross Hiproly-15/Peatland-9, F2 adult plants segregated 3R: 1S to race MCC, confirming the presence of gene Rpg1 in Peatland-9. Some F3 lines derived from F2 plants with Rpg1 were susceptible to race QCC, however, indicating that Rpg1 was ineffective against race QCC. A second gene in Peatland-9, designated for the interim as RpgU and independent of Rpg1, was shown to confer a moderate level of resistance to race QCC. Similar segregation patterns in the presence of race QCC and pedigree analysis suggested that the cultivars Husky and Diamond contain this gene. This gene is likely present in other related cultivars such as Vantage and Bonanza. Segregation in progeny of the cross Hiproly-15/Q21861 indicated that resistance to race QCC was controlled by two recessive genes in Q21861. Gene Rpg2, tested in F3 lines, was found to provide a moderate level of resistance to race QCC, similar to RpgU, but was less effective in the heterozygous condition. The phenotypic expression of RpgU differed from Rpg1, Rpg2, and Rpg3, suggesting that RpgU is a previously unreported gene for stem rust resistance in cultivated barley. Key words: Barley, Hordeum vulgare, stem rust, Puccinia graminis, resistance


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