Pmr1, a Gene for Resistance to Powdery Mildew in Sweet Cherry

Most sweet cherry (Prunus avium L.) cultivars grown commercially in the United States are susceptible to powdery mildew, caused by the fungus Podosphaera clandestina (Wall.:Fr.) Lev. Recently, hybrid populations segregating for resistance to powdery mildew were developed by crossing a mildew-resistant sweet cherry selection, PMR-1, with the susceptible cultivars Bing, Rainier, and Van. Although segregation within these populations indicated a single gene was responsible for the powdery mildew resistance conferred by PMR-1, the gene action could not be determined. Therefore, a reciprocal cross between `Bing' and `Van' was made to determine the allelic state of the susceptible parents used previously. All progeny (n = 286) from this cross were susceptible to powdery mildew. This information, combined with results from previous segregation data, indicate the powdery mildew resistance gene is inherited in a dominant manner and is present in PMR-1 in the heterozygous allelic state. We have named this gene Pmr1. Furthermore, in combination with known pedigree information, we have been able to predict the susceptibility of more than 60 additional commercial and recently released sweet cherry cultivars.

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Inheritance of Powdery Mildew Resistance in Sweet Cherry

HortScience ◽

10.21273/hortsci.36.2.337 ◽

2001 ◽

Vol 36 (2) ◽

pp. 337-340 ◽

Cited By ~ 7

Author(s):

James W. Olmstead ◽

Gregory A. Lang ◽

Gary G. Grove

Keyword(s):

Powdery Mildew ◽

Sweet Cherry ◽

Prunus Avium ◽

Powdery Mildew Resistance ◽

Single Gene ◽

Genetic Resistance ◽

The United States ◽

Washington State ◽

Irrigated Agriculture ◽

Mildew Resistance

Most sweet cherry (Prunus avium L.) cultivars grown commercially in the Pacific Northwestern states of the United States are susceptible to powdery mildew, caused by the fungus Podosphaera clandestina (Wall.:Fr.) Lev. The disease is prevalent in the irrigated arid region east of the Cascade Mountains in Washington State. Little is known about genetic resistance to powdery mildew in sweet cherry, although a selection (PMR-1) was identified at Washington State Univ.'s Irrigated Agriculture Research and Extension Center that exhibits apparent foliar immunity to the disease. The objective of this research was to determine the inheritance of powdery mildew resistance from PMR-1. Reciprocal crosses were made between PMR-1 and three high-quality, widely-grown susceptible cultivars (`Bing', `Rainier', and `Van'). Resultant progenies were screened for reaction to powdery mildew colonization using a laboratory leaf disk assay. Assay results were verified by natural spread of powdery mildew among the progeny in a greenhouse and later by placing them among infected trees in a cherry orchard. Segregation within the progenies for powdery mildew reaction fit a 1 resistant: 1 susceptible segregation ratio (P ≤ 0.05), indicating that resistance to powdery mildew derived from PMR-1 was conferred by a single gene.

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089 Inheritance of Powdery Mildew Resistance in Sweet Cherry (Prunus avium L.)

HortScience ◽

10.21273/hortsci.35.3.404a ◽

2000 ◽

Vol 35 (3) ◽

pp. 404A-404

Author(s):

James W. Olmstead ◽

Gregory A. Lang ◽

Gary G. Grove

Keyword(s):

Powdery Mildew ◽

Sweet Cherry ◽

Prunus Avium ◽

Powdery Mildew Resistance ◽

Single Gene ◽

Genetic Resistance ◽

Segregation Ratio ◽

Washington State ◽

Irrigated Agriculture ◽

Mildew Resistance

Most sweet cherry (Prunus avium L.) cultivars grown commercially in the Pacific Northwest U.S. are susceptible to powdery mildew caused by the fungus Podosphaera clandestina (Wall.:Fr.) Lev. The disease is prevalent in the irrigated arid region east of the Cascade Mountains in Washington State. Little is known about genetic resistance to powdery mildew in sweet cherry, although a selection (`PMR-1') was identified at the Washington State Unive. Irrigated Agriculture Research and Extension Center that exhibits apparent foliar immunity to the disease. The objective of this research was to characterize the inheritance of powdery mildew resistance from `PMR-1'. Reciprocal crosses between `PMR-1' and three high-quality, widely-grown susceptible cultivars (`Bing', `Rainier', and ëVaní) were made to generate segregating progenies for determining the mode of inheritance of `PMR-1' resistance. Progenies were screened for susceptibility to powdery mildew colonization using a laboratory leaf disk assay. Assay results were verified by natural spread of powdery mildew among the progeny seedlings in a greenhouse and later by placement among infected trees in a cherry orchard. Progenies from these crosses were not significantly different (P > 0.05) when tested for a 1:1 resistant to susceptible segregation ratio, indicating that `PMR-1' resistance is conferred by a single gene, which we propose to designate as PMR-1.

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Revisiting the S-allele Nomenclature in Sweet Cherry (Prunus avium) Using RFLP Profiles

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.126.6.654 ◽

2001 ◽

Vol 126 (6) ◽

pp. 654-660 ◽

Cited By ~ 17

Author(s):

Nathanael R. Hauck ◽

Amy F. Iezzoni ◽

Hisayo Yamane ◽

Ryutaro Tao

Keyword(s):

Dna Analysis ◽

Sweet Cherry ◽

Prunus Avium ◽

Restriction Enzymes ◽

The United States ◽

Correct Assignment ◽

Enzyme Combination ◽

Incompatibility Alleles ◽

S Allele ◽

Sweet Cherry Cultivars

Correct assignment of self-incompatibility alleles (S-alleles) in sweet cherry (Prunus avium L.) is important to assure fruit set in field plantings and breeding crosses. Until recently, only six S-alleles had been assigned. With the determination that the stylar product of the S-locus is a ribonuclease (RNase) and subsequent cloning of the S-RNases, it has been possible to use isoenzyme and DNA analysis to genotype S-alleles. As a result, numerous additional S-alleles have been identified; however, since different groups used different strategies for genotype analysis and different cultivars, the nomenclature contained inconsistencies and redundancies. In this study restriction fragment-length polymorphism (RFLP) profiles are presented using HindIII, EcoRI, DraI, or XbaI restriction digests of the S-alleles present in 22 sweet cherry cultivars which were chosen based upon their unique S-allele designations and/or their importance to the United States sweet cherry breeding community. Twelve previously published alleles (S1, S2, S3, S4, S5, S6, S7, S9, S10, S11, S12, and S13) could be differentiated by their RFLP profiles for each of the four restriction enzymes. Two new putative S-alleles, both found in `NY1625', are reported, bringing the total to 14 differentiable alleles. We propose the adoption of a standard nomenclature in which the sweet cherry cultivars `Hedelfingen' and `Burlat' are S3S5 and S3S9, respectively. Fragment sizes for each S-allele/restriction enzyme combination are presented for reference in future S-allele discovery projects.

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Characterization of a Segregation Distortion Locus with Powdery Mildew Resistance in a Wheat-Thinopyrum intermedium Introgression Line WE99

Plant Disease ◽

10.1094/pdis-11-15-1352-re ◽

2016 ◽

Vol 100 (8) ◽

pp. 1541-1547 ◽

Cited By ~ 2

Author(s):

Pengtao Ma ◽

Hongxing Xu ◽

Guohao Han ◽

Qiaoling Luo ◽

Yunfeng Xu ◽

...

Keyword(s):

Powdery Mildew ◽

Powdery Mildew Resistance ◽

Single Gene ◽

Introgression Line ◽

Triticum Aestivum L ◽

Thinopyrum Intermedium ◽

Seedling Resistance ◽

Mildew Resistance ◽

Genotype Frequencies ◽

Chromosome Arm

Exploitation of host resistance is important for controlling powdery mildew of wheat (Triticum aestivum L.). In this study, a wheat-Thinopyrum intermedium introgression line, designated WE99, conferred seedling resistance to 47 of 49 Blumeria graminis f. sp. tritici isolates. Genetic analysis demonstrated that the resistance segregation deviated significantly from a single gene Mendelian ratio. However, marker analysis indicated that only a single recessive resistance gene, temporarily designated PmWE99, conferred powdery mildew resistance (Pm). PmWE99 was mapped to chromosome arm 2BS and linked to the three simple-sequence repeat markers Gwm148, Gwm271, and Barc55. Using race spectrum analysis, PmWE99 was shown to be significantly different from the documented genes Pm42 and MlIW170 located on chromosome arm 2BS and, thus, appeared to be a new Pm gene. Examination of the genotype frequencies in the F2:3 families showed that a genetic variation in the PmWE99 interval that favored the transmission of the WE99 allele could be the cause of the deviated segregation. Further investigation revealed that the abnormal segregation only occurred at the PmWE99 interval and was not common at other loci in this population. Identification of PmWE99 will increase the diversity of the Pm genes for wheat improvement.

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Analysis of Sweet Cherry (Prunus avium L.) Cultivars Using SSR and AFLP Markers

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.128.6.0904 ◽

2003 ◽

Vol 128 (6) ◽

pp. 904-909 ◽

Cited By ~ 65

Author(s):

Darush Struss ◽

Riaz Ahmad ◽

Stephen M. Southwick ◽

Manuela Boritzki

Keyword(s):

Sweet Cherry ◽

Prunus Avium ◽

Pcr Primers ◽

The United States ◽

Aflp Markers ◽

Phage Library ◽

Grocery Stores ◽

Market Place ◽

Fruit Flesh ◽

Sweet Cherry Cultivars

Simple sequence repeats (SSRs) and amplified fragment-length polymorphisms (AFLPs) were used to evaluate sweet cherry (Prunus avium L.) cultivars using quality DNA extracted from fruit flesh and leaves. SSR markers were developed from a phage library using genomic DNA of the sweet cherry cultivar Valerij Tschkalov. Microsatellite containing clones were sequenced and 15 specific PCR primers were selected for identification of cultivars in sweet cherry and for cross-species amplification in Prunus. In total, 48 alleles were detected by 15 SSR primer pairs, with an average of 3.2 putative alleles per primer combination. The number of putative alleles ranged from one to five in the tested cherry cultivars. Forty polymorphic fragments were scored in the tested cherry cultivars by 15 SSRs. All sweet cherry cultivars were identified by SSRs from their unique fingerprints. We also demonstrated that the technique of using DNA from fruit flesh for analysis can be used to maintain product purity in the market place by comparing DNA fingerprints from 12 samples of `Bing' fruit collected from different grocery stores in the United States to that of a standard `Bing' cultivar. Results indicated that, with one exception, all `Bing'samples were similar to the standard. Amplification of more than 80% of the sweet cherry primer pairs in plum (P. salicina), apricot (P. armeniaca) and peach (P. persica L.) showed a congeneric relationship within Prunus species. A total of 63 (21%) polymorphic fragments were recorded in 15 sweet cherry cultivars using four EcoRI-MseI AFLP primer combinations. AFLP markers generated unique fingerprints for all sweet cherry cultivars. SSRs and AFLP polymorphic fragments were used to calculate a similarity matrix and to perform UPGMA cluster analysis. Most of the cultivars were grouped according to their pedigree. The SSR and AFLP molecular markers can be used for the grouping and identification of sweet cherry cultivars as a complement to pomological studies. The new SSRs developed here could be used in cherry as well as in other Prunus species for linkage mapping, evolutionary and taxonomic study.

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A Leaf Disk Assay for Screening Sweet Cherry Genotypes for Susceptibility to Powdery Mildew

HortScience ◽

10.21273/hortsci.35.2.274 ◽

2000 ◽

Vol 35 (2) ◽

pp. 274-277 ◽

Cited By ~ 11

Author(s):

James W. Olmstead ◽

Gregory A. Lang ◽

Gary G. Grove

Keyword(s):

Powdery Mildew ◽

Sweet Cherry ◽

Prunus Avium ◽

Leaf Age ◽

Nutrient Content ◽

Field Resistance ◽

Leaf Disk ◽

Detached Leaf ◽

Breeding Populations ◽

Sweet Cherry Cultivars

A detached leaf disk assay for screening sweet cherry (Prunus avium L.) genotypes for susceptibility to powdery mildew (PM) [Podosphaera clandestina (Wallr.:Fr.) Lev.] was developed by evaluating the effects of photoperiod (24 hours light, 0 hours light, 14 hours light/10 hours dark), substrate nutrient content (sterile distilled water, 1% sucrose), leaf age (old, young, emergent), and leaf explant size (intact leaf, 30 mm, 20 mm) on PM growth on leaves from the susceptible cultivar Bing. The only parameter described that had a significant (P ≤ 0.001) effect on PM growth was leaf age. Old leaves, designated as the third fully expanded leaf from the basal end of current-year's shoot growth, were never infected with PM under controlled inoculations. In the absence of significant differences between treatments, those parameters with the highest treatment means were selected for subsequent evaluation. To test the leaf disk assay, 14 sweet cherry cultivars were screened in two experiments, and rated according to level of PM susceptibility. Rank sum comparison of results from cultivars used for leaf disk screening agreed with earlier field rankings of the same cultivars. The developed leaf disk assay greatly reduced the space required to screen sweet cherry cultivars, and was a repeatable and objective predictor of field resistance that may be useful for screening germplasm or breeding populations.

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Genetics of Resistance to Wheat Leaf Rust, Stem Rust, and Powdery Mildew in Aegilops sharonensis

Phytopathology ◽

10.1094/phyto-98-3-0353 ◽

2008 ◽

Vol 98 (3) ◽

pp. 353-358 ◽

Cited By ~ 12

Author(s):

P. D. Olivera ◽

E. Millet ◽

Y. Anikster ◽

B. J. Steffenson

Keyword(s):

Powdery Mildew ◽

Leaf Rust ◽

Stem Rust ◽

Powdery Mildew Resistance ◽

Single Gene ◽

Adult Plant ◽

Mildew Resistance ◽

Aegilops Sharonensis ◽

Plant Stage ◽

Allelism Tests

Aegilops sharonensis (Sharon goatgrass) is a wild relative of wheat and a rich source of genetic diversity for disease resistance. The objectives of this study were to determine the genetic basis of leaf rust, stem rust, and powdery mildew resistance in A. sharonensis and also the allelic relationships between genes controlling resistance to each disease. Progeny from crosses between resistant and susceptible accessions were evaluated for their disease reaction at the seedling and/or adult plant stage to determine the number and action of genes conferring resistance. Two different genes conferring resistance to leaf rust races THBJ and BBBB were identified in accessions 1644 and 603. For stem rust, the same single gene was found to confer resistance to race TTTT in accessions 1644 and 2229. Resistance to stem rust race TPMK was conferred by two genes in accessions 1644 and 603. A contingency test revealed no association between genes conferring resistance to leaf rust race THBJ and stem rust race TTTT or between genes conferring resistance to stem rust race TTTT and powdery mildew isolate UM06-01, indicating that the respective resistance genes are not linked. Three accessions (1644, 2229, and 1193) were found to carry a single gene for resistance to powdery mildew. Allelism tests revealed that the resistance gene in accession 1644 is different from the respective single genes present in either 2229 or 1193. The simple inheritance of leaf rust, stem rust, and powdery mildew resistance in A. sharonensis should simplify the transfer of resistance to wheat in wide crosses.

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