Gene-for-gene interactions between the rye mildew fungus and wheat cultivars

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 758-762 ◽  
Author(s):  
Y. Tosa
Keyword(s):  
Triticum Aestivum ◽  
Powdery Mildew ◽  
Chinese Spring ◽  
Single Gene ◽  
Erysiphe Graminis ◽  
Gene Interactions ◽  
Wheat Cultivars ◽  
Genetic Mechanisms ◽  
Host Parasite ◽  
Gene For Gene

Genetic mechanisms of the incompatibility between Erysiphe graminis f.sp. secalis and wheat cultivars were analyzed using F1 hybrids between E. graminis f.sp. secalis, Sk-1, and f.sp. tritici, Tk-1. The avirulence of Sk-1 on Triticum aestivum 'Norin 4', 'Chinese Spring', and 'Kokeshi-komugi' was controlled by a single gene. The resistance of the three cultivars to Sk-1 was also controlled by a single gene, Pm15, a gene for resistance to E. graminis f.sp. agropyri. Implications of these results were discussed in terms of host–parasite coevolution.Key words: powdery mildew, Erysiphe graminis, resistance, wheat.

scholarly journals A Gene-for-Gene Relationship Underlying the Species-Specific Parasitism of Avena/Triticum Isolates of Magnaporthe grisea on Wheat Cultivars

2002 ◽  
Vol 92 (11) ◽  
pp. 1182-1188 ◽  
Author(s):  
N. Takabayashi ◽  
Y. Tosa ◽  
H. S. Oh ◽  
S. Mayama
Keyword(s):  
Resistance Gene ◽  
Temperature Sensitivity ◽  
Chinese Spring ◽  
Magnaporthe Grisea ◽  
Gene Interactions ◽  
Wheat Cultivars ◽  
Genetic Mechanisms ◽  
Species Specific ◽  
Cultivar Specificity ◽  
Gene For Gene

To elucidate genetic mechanisms of the species-specific parasitism of Magnaporthe grisea, a Triticum isolate (pathogenic on wheat) was crossed with an Avena isolate (pathogenic on oat), and resulting F1 progeny were subjected to segregation analyses on wheat cvs. Norin 4 and Chinese Spring. We found two fungal loci, Pwt3 and Pwt4, which are involved in the specific parasitism on wheat. Pwt3 operated on both cultivars while Pwt4 operated only on ‘Norin 4’. Using the cultivar specificity of Pwt4, its corresponding resistance gene was successfully identified in ‘Norin 4’ and designated as Rmg1 (Rwt4). The presence of the corresponding resistance gene indicated that Pwt4 is an avirulence locus. Pwt3 was assumed to be an avirulence locus because of its temperature sensitivity. We suggest that gene-for-gene interactions underlie the species-specific parasitism of M. grisea.

Genetic analysis of the avirulence of wheatgrass powdery mildew fungus on common wheat

Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 913-917 ◽  
Author(s):  
Y. Tosa
Keyword(s):  
Triticum Aestivum ◽  
Powdery Mildew ◽  
Genetic Analysis ◽  
Common Wheat ◽  
Erysiphe Graminis ◽  
Wheat Cultivars ◽  
Avirulence Genes ◽  
Powdery Mildew Fungus ◽  
Major Genes ◽  
Formae Speciales

F1 hybrid cultures between Erysiphe graminis f.sp. agropyri (wheatgrass mildew fungus) and E. graminis f.sp. tritici (wheat mildew fungus) were produced by using a common host of the two formae spéciales. When three common wheat cultivars, Triticum aestivum cv. Norin 4, T. aestivum cv. Norin 10, and T. compactum cv. No. 44, were inoculated with a population of F1 cultures, avirulent and virulent cultures segregated in a 3:1 ratio. This indicated that two major genes are involved in the avirulence of E. graminis f.sp. agropyri, Ak-1, on each of the three cultivars. Further analyses revealed that the three pairs of avirulence genes have one gene in common. On T. aestivum cv. Shin-chunaga, T. aestivum cv. Norin 26, and a strain of T. macha, the F1 population segregated in the same pattern as on T. aestivum cv. Norin 4, indicating that the same pair of avirulence genes is operating on these four cultivars. On T. aestivum cv. Red Egyptian the distribution of F1 phenotypes was continuous, suggesting that no major genes are involved in the avirulence of Ak-1 on this cultivar.Key words: powdery mildew, Erysiphe graminis, avirulence, wheat, wheatgrass.

Identification of a gene for resistance to wheatgrass powdery mildew fungus in the common wheat cultivar Chinese Spring

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 612-614 ◽  
Author(s):  
Y. Tosa ◽  
H. Tokunaga ◽  
H. Ogura
Keyword(s):  
Triticum Aestivum ◽  
Powdery Mildew ◽  
Common Wheat ◽  
Chinese Spring ◽  
Wheat Cultivar ◽  
Erysiphe Graminis ◽  
Common Wheat Cultivar ◽  
Powdery Mildew Fungus ◽  
Hybrid Culture ◽  
The Common

A gene for resistance to Erysiphe graminis was detected in Triticum aestivum cv. Chinese Spring, strain Salmon, T. compactum cv. No. 44, and T. spelta var. duhamelianum, using a hybrid culture derived from E. graminis f. sp. agropyri × E. graminis f. sp. tritici. The gene was located on the short arm of chromosome 6B and designated Pm11. Pm11 was considered to be involved in the resistance of wheat to the wheatgrass powdery mildew fungus.Key words: wheat, resistance, powdery mildew, Erysiphe graminis.

The genetics of resistance of hexaploid wheat to the wheatgrass powdery mildew fungus

Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Y. Tosa ◽  
K. Sakai
Keyword(s):  
Triticum Aestivum ◽  
Powdery Mildew ◽  
Erysiphe Graminis ◽  
Cultivar Resistance ◽  
Genetics Of Resistance ◽  
Powdery Mildew Fungus ◽  
The Third ◽  
Forma Specialis ◽  
Cultivar Specificity ◽  
Gene For Gene

The avirulence of Erysiphe graminis f.sp. agropyri, Ak-1, on Triticum aestivum 'Norin 4' and 'Norin 10' and T. compactum 'No.44' is conditioned by four genes; three operate singly against each cultivar and one operates against all three cultivars. If the forma specialis – genus specificity follows the gene-for-gene relationship, four major genes should be involved in the resistance of the three cultivars to Ak-1, one carried only by 'Norin 4', one carried only by 'No.44', one carried only by 'Norin 10', and one carried by all three cultivars. The first and second genes were considered to be the previously reported genes Pm10 and Pm11, respectively. The third and fourth genes were successfully detected using F1 hybrid cultures between Ak-1 and E. graminis f.sp. tritici, Tk-1. They were located on chromosomes 6B and 7D and designated Pm14 and Pm15, respectively. These results strongly support the assumption that the forma specialis – genus specificity follows the gene-for-gene relationship. It is, therefore, concluded that this type of specificity belongs to cultivar specificity rather than plant-species specificity and that the resistance to inappropriate formae speciales is essentially cultivar resistance and not nonhost resistance.Key words: powdery mildew, Erysiphe graminis, wheat, wheatgrass, resistance.

INHERITANCE OF SEED COAT COLOR IN EIGHT SPRING WHEAT CULTIVARS

1981 ◽  
Vol 61 (3) ◽  
pp. 719-721 ◽  
Author(s):  
R. J. BAKER
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Seed Coat ◽  
Coat Color ◽  
Single Gene ◽  
Triticum Aestivum L ◽  
Seed Coat Color ◽  
Wheat Cultivars

Segregation for seed coat color was studied in F2 populations of crosses between eight red-seeded and three white-seeded cultivars of spring wheat (Triticum aestivum L. em Thell). Red Bobs and Pitic 62 each possessed a single gene for red seed coat color; Glenlea and NB320 each carried two genes; Neepawa, Park and RL4137 each possessed three genes. Data for crosses with Manitou were not sufficient to distinguish between the presence of two or three genes for seed coat color in this cultivar.

scholarly journals The impact of environmental change on host–parasite coevolutionary dynamics

2010 ◽  
Vol 278 (1716) ◽  
pp. 2283-2292 ◽  
Author(s):  
Rafal Mostowy ◽  
Jan Engelstädter
Keyword(s):  
Environmental Change ◽  
Environmental Changes ◽  
Selective Pressure ◽  
Time Windows ◽  
Gene Interactions ◽  
Genotype By Environment ◽  
Host Parasite ◽  
The Impact ◽  
Antagonistic Interactions ◽  
Gene For Gene

Environmental factors are known to affect the strength and the specificity of interactions between hosts and parasites. However, how this shapes patterns of coevolutionary dynamics is not clear. Here, we construct a simple mathematical model to study the effect of environmental change on host–parasite coevolutionary outcome when interactions are of the matching-alleles or the gene-for-gene type. Environmental changes may effectively alter the selective pressure and the level of specialism in the population. Our results suggest that environmental change altering the specificity of selection in antagonistic interactions can produce alternating time windows of cyclical allele-frequency dynamics and cessation thereof. This type of environmental impact can also explain the maintenance of polymorphism in gene-for-gene interactions without costs. Overall, our study points to the potential consequences of environmental variation in coevolution, and thus the importance of characterizing genotype-by-genotype-by-environment interactions in natural host–parasite systems, especially those that change the direction of selection acting between the two species.

The interface between the powdery mildew haustorium and the cytoplasm of the susceptible barley epidermal cell

1974 ◽  
Vol 20 (11) ◽  
pp. 1475-1478 ◽  
Author(s):  
W. E. McKeen
Keyword(s):  
Powdery Mildew ◽  
Thin Layer ◽  
Epidermal Cell ◽  
Erysiphe Graminis ◽  
Host Cytoplasm ◽  
Host Parasite

The host–parasite interface separating the haustorium of Erysiphe graminis and the cytoplasm of the barley epidermal cell is an invaginated portion of the host plasmalemma which becomes thicker, more osmophilic, highly invaginated toward the haustorium, and which loses its transparent central stratum. This extrahaustorial membrane is always 1–4 μm distant from the haustorial wall and at first is covered with a thin layer of normal cytoplasm. Later, the host cytoplasm greatly increases in volume, becomes much less dense, and organelles become less confined.

Cytogenetic studies on a heterozygous reciprocal translocation in the wheat (Triticum aestivum) cultivar Atlas 66

Genome ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 313-316
Author(s):  
Sandra J. Primard ◽  
Rosalind Morris ◽  
Charles M. Papa
Keyword(s):  
Triticum Aestivum ◽  
Reciprocal Translocation ◽  
Chinese Spring ◽  
Triticum Aestivum L ◽  
The Other ◽  
Wheat Cultivars ◽  
Cytogenetic Studies ◽  
A Chain ◽  
Seven Generations ◽  
I Cells

The wheat (Triticum aestivum L.) cultivar Atlas 66 possesses a heterozygous reciprocal translocation that has persisted through seven generations of self-pollination and also has appeared in progeny of crosses between cv. Atlas 66 and other wheat cultivars or lines. Crosses were made between cv. Atlas 66 and the 21 cv. Chinese Spring double ditelosomics to identify the chromosomes involved in the translocation. F1 plants testing chromosomes 2A and 2D had a chain with one telosome attached and the other unpaired in some metaphase I cells, indicating that 2A and 2D were involved in the translocation. The F1s testing the other 19 chromosomes had a chain of four and a trivalent that included the two telosomes. F1 meiotic configurations from crosses between cv. Altas 66 and cv. Chinese Spring ditelosomics 2AS, 2AL, 2DS, and 2DL indicated that the breakpoints were in 2AL and 2DL and that the breakpoint in 2DL was closer to the end of the arm than the breakpoint in 2AL. The short translocated 2DL segment could explain the occurrence of chains as well as rings when cv. Atlas 66 was self-pollinated, and a predominance of chains in crosses with other cultivars or lines. There was evidence for the transmission of duplicate-deficient gametes from the translocation.Key words: heterozygous reciprocal translocation, Triticum aestivum, wheat, cv. Atlas 66.

scholarly journals Genetic and Cytogenetic Studies of Stem Rust, Leaf Rust, and Powdery Mildew Resistances in Hope and Related Wheat Cultivars

1967 ◽  
Vol 20 (6) ◽  
pp. 1181 ◽  
Author(s):  
RA Mcintosh ◽  
NH Luig ◽  
EP Baker
Keyword(s):  
Powdery Mildew ◽  
Leaf Rust ◽  
Stem Rust ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Stem Rust Resistance ◽  
Gene Interactions ◽  
Adult Plant ◽  
Wheat Cultivars ◽  
Cytogenetic Studies

Three linked genes responsible for resistance respectively to stem rust, to leaf rust, and to powdery mildew are located on chromosome 7B of Hope wheat. The gene for stem rust resistance, operative in seedling and adult plant stages, is recessive and is designated Br17. The incompletely dominant gene for resistance to leaf rust, designated Lr14, showed 18% recombination with sr17, whilst in two different crosses recombination estimates of 6�0 and 2�5%, respectively, were obtained for the recessive gene for mildew resistance and Br17. All three genes were found to be present in a high proportion of Hope and H�44 derivatives. The gene Br 1'7 is apparently ineffective in conferring resistance to North American and pre.1954 Australian stem rust strains. Its incorporation into several cultivars selected for resistance to these strains presumably resulted from gene interactions or linkage with genes for resistance to other diseases.

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