Gene-for-gene relationships in the Avena: Puccinia graminis host–parasite system in Canada

1970 ◽  
Vol 48 (5) ◽  
pp. 969-975 ◽  
Author(s):  
J. W. Martens ◽  
R. I. H. McKenzie ◽  
G. J. Green
Keyword(s):  
North America ◽  
Resistance Genes ◽  
Stem Rust ◽  
Host Population ◽  
Puccinia Graminis ◽  
Physiologic Race ◽  
Host Genotype ◽  
Physiologic Races ◽  
Host Parasite ◽  
Gene For Gene

The results of 48 years of oat stem rust physiologic race surveys are interpreted in terms of the prevailing host genotype. Changes in the frequencies of genes that govern virulence in the pathogen can be explained only in part by changes in the resistance genes carried by the host population. Genes for virulence on newly released types of resistance have spread very quickly through the rust population, after initial 'breakdown' of the resistance. The most successful physiologic races carry genes for virulence in excess of those required for successful parasitism in North America. Many races carry genes for virulence on types of resistance that have never been used on this continent.

scholarly journals Seedling Stage Resistance of Iranian Bread Wheat Germplasm to Race Ug99 of Puccinia graminis f. sp. tritici

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Mohsen Mohammadi ◽  
Davoud Torkamaneh ◽  
Mehran Patpour
Keyword(s):  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Wheat Cultivars ◽  
Breeding Lines ◽  
Wheat Germplasm ◽  
Stem Rust Resistance Genes ◽  
Rust Resistance Genes

Following emergence of Ug99, the new virulent race of Puccinia graminis f. sp. tritici in Africa, a global effort for identification and utilization of new sources of Ug99-resistant germplasm has been undertaken. In this study, we conducted replicated experiments to evaluate the resistance of Iranian wheat germplasm to the TTKSK lineage of the Ug99 race of P. graminis f. sp. tritici. We also evaluated for presence of stem rust resistance genes (i.e., Sr2, Sr24, Sr26, Sr38, Sr39, Sr31, and Sr1RSAmigo) in wheat cultivars and breeding lines widely cultivated in Iran. Our phenotyping data revealed high levels of susceptibility to Ug99 in Iranian bread wheat germplasm. Our genotyping data revealed that Iranian cultivars do not carry Sr24, Sr26, or Sr1RSAmigo. Only a few salt-tolerant cultivars and breeding lines tested positively for Sr2, Sr31, Sr38, or Sr39 markers. In conclusion, the genetic basis for resistance to Ug99 in Iranian wheat cultivars was found to be vulnerable. Acquiring knowledge about existing resistance genes and haplotypes in wheat cultivars and breeding lines will help breeders, cereal pathologists, and policy makers to select and pyramid effective stem rust resistance genes.

PHYSIOLOGIC SPECIALIZATION OF OAT STEM RUST IN CANADA

1944 ◽  
Vol 22c (5) ◽  
pp. 201-216 ◽  
Author(s):  
Margaret Newton ◽  
T. Johnson
Keyword(s):  
Stem Rust ◽  
Wide Distribution ◽  
Puccinia Graminis ◽  
Characteristic Type ◽  
Influence Of Temperature ◽  
Physiologic Specialization ◽  
Influence Of Temperature On ◽  
Physiologic Races

An account is given of the results of studies on the physiologic specialization of Puccinia graminis Avenae Erikss. and Henn. in Canada since the inception of the work. Twelve physiologic races were identified from 2586 isolates studied during the period 1921 to 1943. The annual surveys of the prevalence of physiologic races during this period show that each year races 1, 2, and 5 have comprised the bulk of the oat stem rust in all parts of Canada. The predominance of these races has been greatest in the three Prairie Provinces, where barberry is virtually non-existent. In regions where barberry is present, other races of greater range of pathogenicity have been found more frequently than in these three provinces. The occurrence of such races, however, was sporadic until 1943, in which year races 8, 10, and 11 attained a wide distribution, apparently traceable to wind-borne urediospores from the south. There is evidence that the strains of these races present in 1943 remain in the uredial stage for much longer periods than do strains of the same races collected in previous years—a fact that may have favoured their spread in this year.The role of barberry in the origination of generally virulent physiologic races is discussed. The possibility that such races may also originate by mutation is suggested by spontaneous pathogenic changes that occurred, in the greenhouse, in a culture of race 3 that gave rise to several cultures of race 7.The effect of environment on the identification of physiologic races is demonstrated by the seasonal influences on the reaction of the variety Sevnothree to races 1 and 11. On this variety the characteristic type 1 is frequently replaced, in summer, by type x.Experiments on the influence of temperature on the reaction of adult oat plants to stem rust showed that a constant temperature of about 80° F. does not appreciably affect the reaction of White Tartar and Richland, or of other varieties with the same type of resistance, but is capable of breaking down the resistance of certain varieties derived from the crosses Hajira × Joanette, Hajira × Banner, and Victoria × (Hajira × Banner).

THE EFFECT OF DDT ON THE STEM RUST REACTION OF KHAPLI WHEAT

1946 ◽  
Vol 24c (2) ◽  
pp. 23-25 ◽  
Author(s):  
T. Johnson
Keyword(s):  
North America ◽  
Stem Rust ◽  
Wheat Stem Rust ◽  
Physiologic Races

Seedling leaves of Khapli wheat—a variety highly resistant to physiologic races of wheat stem rust prevalent in North America—became susceptible to stem rust a few days after they had been sprayed with DDT (1 oz. in 5 gal. water). The response to DDT was highly specific, as only one other of the resistant wheats tested (Arnautka) showed any indication of susceptibility consequent on spraying. Specificity of response was also indicated by the development of marked chlorosis on leaves of some varieties, whereas other varieties remained unaffected.

THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: XVIII. DISTRIBUTION OF TRITIUM-LABELLED CYTIDINE, URIDINE, AND LEUCINE IN WHEAT LEAVES INFECTED WITH THE STEM RUST FUNGUS

1967 ◽  
Vol 45 (5) ◽  
pp. 555-563 ◽  
Author(s):  
P. K. Bhattacharya ◽  
Michael Shaw
Keyword(s):  
Stem Rust ◽  
Rust Fungus ◽  
Host Cells ◽  
Fungal Mycelium ◽  
Puccinia Graminis ◽  
Mesophyll Cells ◽  
Wheat Leaves ◽  
Host Parasite

Wheat leaves were detached 6 days after inoculation with the stem rust fungus (Puccinia graminis var. tritici Erikss. and Henn.) and fed with tritiated leucine, cytidine, uridine, or thymidine. Mesophyll cells in infected zones incorporated more leucine into protein and more cytidine and uridine into RNA than did cells in adjacent uninfected tissue. Leucine, cytidine, and uridine were also heavily incorporated by fungal mycelium and developing uredospores. Grain counts over host nuclei in the infected zone were two to three-fold of those over nuclei in adjacent uninfected zones. There was no detectable incorporation of thymidinemethyl-3H into either the fungus or the host cells. The results are discussed.

THE SOURCE OF RESISTANCE AND THE INHERITANCE OF REACTION TO 12 PHYSIOLOGIC RACES OF STEM RUST, PUCCINIA GRAMINIS AVENAE (ERIKSS. AND HENN.)

1951 ◽  
Vol 29 (3) ◽  
pp. 189-205 ◽  
Author(s):  
J. N. Welsh ◽  
T. Johnson
Keyword(s):  
United States ◽  
Stem Rust ◽  
Adult Stage ◽  
The United States ◽  
Puccinia Graminis ◽  
Probable Explanation ◽  
Main Gene ◽  
Physiologic Races

Resistance to 12 races of oat stem rust was unexpectedly obtained from three crosses, Hajira–Jostrain, Hajira–Richland, and Hajira–Banner, between the years 1932 and 1940. Recent investigations have shown that the Hajira parent was the source of this resistance, as 10% of plants selected from this variety were found to be highly resistant. Inheritance studies have shown that, in some crosses involving this source of resistance, two main genes are involved and in others only a single main gene. A probable explanation is that the highly resistant plants in Hajira may have differed genetically. The studies also reveal that the Hajira type of resistance to race 8, either in the seedling or adult stage, is indicative of resistance to the 12 races that occur in Canada and the United States.

Molecular aspects of avirulence genes of the tomato pathogen Cladosporium fulvum

1995 ◽  
Vol 73 (S1) ◽  
pp. 490-494 ◽  
Author(s):  
Pierre J. G. M. de Wit ◽  
Matthieu H. A. J. Joosten ◽  
Guy Honée ◽  
Paul J. M. J. Vossen ◽  
Ton J. Cozijnsen ◽  
...  
Keyword(s):  
Host Plant ◽  
Resistance Genes ◽  
Hypersensitive Response ◽  
Fungal Pathogens ◽  
Direct Interaction ◽  
Defense Responses ◽  
Cladosporium Fulvum ◽  
Avirulence Genes ◽  
Host Genotype ◽  
Gene For Gene

Host genotype specificity in interactions between biotrophic fungal pathogens and plants in most cases complies with the gene-for-gene model. Success or failure of infection is determined by the absence or presence of complementary genes, avirulence and resistance genes, in the pathogen and the host plant, respectively. Resistance, expressed by the induction of a hypersensitive response followed by other defence responses in the host, is envisaged to be based on recognition of the pathogen, mediated through direct interaction between products of avirulence genes of the pathogen (the so-called race-specific elicitors) and receptors in the host plant, the putative products of resistance genes. The interaction between the biotrophic fungus Cladosporium fulvum and its only host, tomato, is a model system to study fungus–plant gene-for-gene relationships. Here we review research on isolation, characterization, and biological function of two race-specific elicitors AVR4 and AVR9 of C. fulvum and cloning and regulation of their encoding genes. Key words: avirulence genes, race-specific elicitors, resistance genes, hypersensitive response, host defense responses.

scholarly journals Pathogenic Variability of Wheat Stem Rust Pathogen (Puccinia graminis f. sp. tritici) in Hararghe Highlands, Ethiopia

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Arif Abrahim ◽  
Temam Hussein ◽  
Ayele Badebo
Keyword(s):  
Resistance Genes ◽  
Stem Rust ◽  
Agricultural Research ◽  
Low Frequency ◽  
Puccinia Graminis ◽  
Total Production ◽  
Rust Disease ◽  
Wheat Stem Rust ◽  
Pathogenic Variability ◽  
Infection Types

Wheat is one of the important major crops of Hararghe Highlands. It is third in land coverage and total production after sorghum and maize. However, the wheat stem rust disease is threatening production of wheat in this region. So, this research was conducted with the following objective: to determine the population of Puccinia graminis f. sp. tritici in Hararghe Highlands. A total of 200 fields were surveyed and stem rust samples were collected and transported to Kulumsa Agricultural Research Center for race analysis. Inoculation of differentials carrying resistance genes Sr24 and Sr-Tmp indicated typical low infection types on all isolates. Isolates EH5, EH8, and EH3 from East Hararghe and WH2, WH1, and WH3 from West Hararghe showed high virulence of infection in all differential lines. Ten (10) races were identified by using Puccinia graminis tritici code system: TTGSK, PTJQK, TTSSK, TTKSK, TRSSK, and TTJQK from East Hararghe and TTTSK and TTSQK from West Hararghe zones. Race TTSSK was most frequent (25%) followed by TTKSK (25%) in East Hararghe. Race TTSSK showed 50% frequency of occurrence in West Hararghe zones. The low frequency of occurrences indicated high variability of the races in the survey areas. Therefore, monitoring of populations of pathogens is important for the national and regional research centers. Detection of pathogen virulence evolution and of currently effective resistance genes is necessary and must be applied within a system of resistance gene management.

Physiologic races of wheat stem rust in Canada from 1919 to 1969

1971 ◽  
Vol 49 (9) ◽  
pp. 1575-1588 ◽  
Author(s):  
G. J. Green
Keyword(s):  
Resistance Genes ◽  
Stem Rust ◽  
Single Gene ◽  
Effective Resistance ◽  
Stabilizing Selection ◽  
New Combinations ◽  
Wheat Stem Rust ◽  
The Past ◽  
Physiologic Races ◽  
New System

The races of wheat stem rust found in Canada and identified by the "standard" and "formula" methods are described. Seven races or race groups made up 90.8% of the isolates. In 1964 a new system of race identification was introduced. It makes use of virulence formulas consisting of the numbers of effective resistance genes in the numerator and ineffective genes in the denominator. Resistance genes Sr6, Sr8, Sr9a, Sr9b, and Sr13 confer resistance to most isolates obtained since 1964, but no single gene confers resistance to all isolates. Experience shows that 250 isolates per year are sufficient to establish the trends of prevalence of the main races. The detection of rare, new combinations of virulence requires screening varieties carrying combinations of resistance genes. The main races in the past 50 years have been 56 and 15B. Race 56 is uniform with a single subrace but 15B is variable with many subraces. There is no evidence that unnecessary virulence is harmful or that "stabilizing selection" is operative in Canada, nor is there evidence that virulence on resistance genes Sr6 and Sr11 is harmful to the rust.

SELFING STUDIES WITH PHYSIOLOGIC RACES OF WHEAT STEM RUST, PUCCINIA GRAMINIS VAR TRITICI

1954 ◽  
Vol 32 (4) ◽  
pp. 506-522 ◽  
Author(s):  
T. Johnson
Keyword(s):  
Stem Rust ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Recessive Character ◽  
Triticum Vulgare ◽  
Pathogenic Variation ◽  
Differential Hosts ◽  
Physiologic Races ◽  
Parent Race

Forty-two cultures of wheat stem rust (Puccinia graminis var. tritici Erikss. and Henn.), comprising 34 physiologic races, were subjected to selfing studies each of which involved the inoculation of barberry plants with the sporidia of a race, and the determination of the races in the uredial cultures derived from the aeciospores. In all of the cultures studied, the pathogenic properties expressed on the differential hosts appeared to be inherited according to the same principles. On the varieties Marquis and Kota (Triticum vulgare), pathogenicity of the races in the progeny tended to resemble that of the parent race. On Reliance (T. vulgare), avirulence was a dominant character, virulence a recessive one. On the durum wheats Arnautka, Mindum, and Spelmar, virulence was a dominant and avirulence a recessive character. On Einkorn (T. monococcum) and on Vernal (T. dicoccum), avirulence was dominant to virulence. In the progenies of some races, pathogenic variation occurred though it did not transgress the circumscribed limits of the parent race; the population therefore consisted chiefly of substrains (biotypes) of the same race.

scholarly journals Two Properties of a Gene-for-Gene Coevolution System under Human Perturbations

1999 ◽  
Vol 89 (9) ◽  
pp. 811-816 ◽  
Author(s):  
P. Sun ◽  
X. B. Yang
Keyword(s):  
Real World ◽  
Host Population ◽  
Resistant Genotype ◽  
Human Perturbation ◽  
Boom And Bust ◽  
Human Perturbations ◽  
Pathogen Populations ◽  
Host Parasite ◽  
Over Time ◽  
Gene For Gene

Recently, the gene-for-gene host-parasite coevolution model of Leonard was extended by incorporating two kinds of perturbations. The first kind was the natural perturbations that include those caused by pathogen migration between the two subpopulations of the host, forward and backward mutations in the host or pathogen populations, and some others. The second kind was human perturbations, such as constantly increasing the percentage of the resistant genotype within the host population each season. In this study, we quantitatively compared the two kinds of perturbations and extended the constantly changing human perturbation to include non-constant perturbations that are more likely to occur in the real world. Two properties of the modified Leonard model were revealed from this study. First, when both human perturbations and natural perturbations are involved, the effects of natural perturbations are very small compared with those of human perturbations. This finding ensures that, in the study of human perturbations, we can simplify the study by ignoring the effects of natural perturbations. Second, through the simulation of nonconstant perturbations, which assumes that the proportion of the resistant genotype of the host population increases over time, we found that the model reproduces the “boom and bust” epidemic cycles that are often found in agroecosystems.

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