scholarly journals Evaluation of Powdery Mildew Resistance in Hydrangea macrophylla

2011 ◽  
Vol 29 (2) ◽  
pp. 60-64 ◽  
Author(s):  
Mark T. Windham ◽  
Sandra M. Reed ◽  
Margaret T. Mmbaga ◽  
Alan S. Windham ◽  
Yonghao Li ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Late Summer ◽  
Sources Of Resistance ◽  
Mildew Resistance ◽  
Potted Plants ◽  
Hydrangea Macrophylla ◽  
Erysiphe Polygoni ◽  
High Level ◽  
Moderately Resistant

Abstract Powdery mildew, Erysiphe polygoni DC, can be a significant problem on Hydrangea macrophylla (Thunb.) Ser. in the landscape in late summer to fall and during greenhouse propagation or production of potted plants. Because very little information related to sources of resistance is available, 90 H. macrophylla cultivars were evaluated for resistance to powdery mildew over a 3-year period. This included 69 H. macrophylla ssp. macrophylla and 18 H. macrophylla ssp. serrata (Thunb.) Makino cultivars, along with three cultivars that are hybrids between the two subspecies. Significant differences among cultivars to powdery mildew were found in all three study years. Three cultivars, ‘Amagi Amacha’, ‘Shirofuji’ and ‘Veitchii’, were among the most resistant each year. ‘Diadem’, ‘Komachi’, and ‘Omacha’ were highly resistant in 2006 and 2008, but only moderately resistant in 2007. ‘Komachi’ and ‘Shirofuji’ were considered unsuitable for breeding purposes as they do not appear to produce fertile flowers. ‘Veitchii’ was the only member of H. macrophylla ssp. macrophylla with a high level of powdery mildew resistance; while all other resistant cultivars were members of H. macrophylla ssp. serrata, not all members of this subspecies are resistant. Results of this study will be useful in breeding powdery mildew resistant H. macrophylla.

scholarly journals Inheritance of Powdery Mildew Resistance in Sugar Beet Derived from Beta vulgaris subsp. maritima

Plant Disease ◽  
2001 ◽  
Vol 85 (6) ◽  
pp. 627-631 ◽  
Author(s):  
R. T. Lewellen ◽  
J. K. Schrandt
Keyword(s):  
Powdery Mildew ◽  
Sugar Beet ◽  
Beta Vulgaris ◽  
Powdery Mildew Resistance ◽  
Major Gene ◽  
Mildew Resistance ◽  
Breeding Lines ◽  
Erysiphe Polygoni ◽  
Moderate Resistance ◽  
High Level

Powdery mildew of sugar beet (Beta vulgaris), caused by Erysiphe polygoni, was introduced into North American in 1974. Since then, chemical control has been needed. Moderate resistance of a slow-mildewing type is known and has been used commercially. High resistance was identified recently in B. vulgaris subsp. maritima accessions WB97 and WB242 and has been backcrossed into sugar beet breeding lines. These enhanced lines were used as sources of powdery mildew resistance to determine the inheritance of resistance. Analyses of segregating testcross families showed that resistance from both sources is inherited as a single, dominant, major gene. The gene symbol Pm is proposed for the resistant allele. The allelism of the resistance from the two wild beet sources was not determined. Pm conditions a high level of resistance, but disease developed on matured leaves late in the season. This late development of mildew on lines and the slow-mildewing trait in susceptible, recurrent lines tended to obfuscate discrete disease ratings.

scholarly journals Evaluation of different sources of resistance for breeding powdery mildew resistant grapevine varieties

1999 ◽  
Vol 5 (1-2) ◽  
Author(s):  
J. Korbuly
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Wild Species ◽  
Powdery Mildew Resistance ◽  
East Asian ◽  
Close Correlation ◽  
Sources Of Resistance ◽  
Mildew Resistance ◽  
Additive Gene ◽  
Different Sources

The appearance of resistance to powdery mildew was investigated on seedling progenies of interspecific crossings. Hybrids of American and East-Asian wild species and one Vitis vinifera variety (Janjal kara) were used as source of resistance in the crossings. The resistance of foliage and of berries were tested in the field at the time of vintage. The degree of resistance was ranked into six classes. In American and Asian hybrid derivatives there were few highly resistant progenies, but in the hybrids of Janjal kara variety more than 90 % of the progenies proved to be highly resistant to powdery mildew. According to the distribution of classes of resistance in the populations the resistance of American and Asian sources are mostly influenced by additive gene affects. The resistance of Janjal kara seemed to be mono or digenic. No close correlation was found between the powdery mildew resistance of the foliage and that of the berries.  

scholarly journals Accumulation of a Protein Associated with Plant Defense in Powdery Mildew Resistant Dogwood (Cornus florida)

2006 ◽  
Vol 24 (2) ◽  
pp. 115-118
Author(s):  
M.T. Mmbaga ◽  
F.J. Avila ◽  
E.F. Howard ◽  
E.L. Myles
Keyword(s):  
Powdery Mildew ◽  
Plant Defense ◽  
Powdery Mildew Resistance ◽  
Cornus Florida ◽  
Defense Proteins ◽  
Mildew Resistance ◽  
Flowering Dogwood ◽  
Plant Defense Proteins ◽  
Powdery Mildew Pathogen ◽  
High Level

Abstract This study was conducted to better understand the nature of powdery mildew resistance in flowering dogwood (Cornus florida L.) and in particular to determine if inducible plant defense proteins are associated with powdery mildew resistance. Results from this study showed an accumulation of a new protein in resistant plants, but not in susceptible plants that were challenged with powdery mildew pathogen (Erysiphe (Sect. Microsphaera) pulchra). The protein accumulated in a high level in the resistant selections at 48 hr after inoculation with the pathogen and that was consistent with the production of pathogenesis related (PR) proteins. The protein was characterized as having an isoelectric point of 7.5 ± 0.5 and molecular weight of 18 ± 2 KD. Partial sequence analysis of this protein revealed homology with PR-10 protein associated with drought resistance in potato and was analogous to other proteins related to resistance in other crops. Repeated analysis showed similar results and suggested that a biochemical mode of resistance involving plant defense proteins may be associated with powdery mildew resistance in flowering dogwood.

scholarly journals New Pathotype Nomenclature for Better Characterisation the Virulence and Diversity of Blumeria graminis f.sp. avenae Populations

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1852
Author(s):  
Sylwia Okoń ◽  
Magdalena Cieplak ◽  
Adam Kuzdraliński ◽  
Tomasz Ociepa
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Host Resistance ◽  
Powdery Mildew Resistance ◽  
Blumeria Graminis ◽  
Sources Of Resistance ◽  
Mildew Resistance ◽  
Differential Set ◽  
Letter Code ◽  
First Time

Fungal cereal pathogens, including Blumeria graminis f.sp. avenae, have the ability to adapt to specific conditions, which in turn leads to overcoming host resistance. An important aspect is the standardized way of characterizing the races and pathotypes of the pathogen. In the presented work, for the first time it was proposed to use a unified letter code that allows describing the pathotypes of B. graminis f.sp. avenae. The set of 14 oat genotypes were used as a differential set. This set included genotypes having so far described powdery mildew resistance genes Pm1–Pm11, and two genotypes (A. sterilis and A. strigosa) with effective sources of resistance to Bga. Based on the analysis of 160 Bga isolates collected in 2016–2019 from 4 locations in Poland, the most numerous was the TBBB pathotype, represented by 30% of the tested isolates. It was present in all analyzed populations. Subsequently, 8.1% and 6.3% of the isolates represented the TBCB and RBBB pathotypes, respectively.

scholarly journals Validation of molecular marker associated with powdery mildew resistance in mungbean

2018 ◽  
Vol 78 (3) ◽  
Author(s):  
Sumangala Bhat ◽  
S. K. Pooja ◽  
A. P. Sarkale
Keyword(s):  
Powdery Mildew ◽  
Ssr Markers ◽  
Ssr Marker ◽  
Powdery Mildew Resistance ◽  
Phenotypic Variance ◽  
Single Marker Analysis ◽  
Mildew Resistance ◽  
F2 Population ◽  
Single Marker ◽  
Erysiphe Polygoni

Powdery mildew caused by Erysiphe polygoni, is one of the major diseases of mungbean (Vigna radiata L. Wilczek), causes yield loss up to 20-40%. The present investigation was undertaken to study the SSR markers associated with powdery mildew resistance in mungbean. The resistant line, TARM1 was crossed with highly susceptible, but popular variety DGGV2 and the F1s were selfed to obtain F2. F2 population was evaluated for response to PM under field conditions. Of the 64 SSR markers studied, only four were found to be polymorphic between two parents (TARM1 and DGGV2). Single marker analysis indicated that one SSR marker (MB-SSR238) showed association with powdery mildew resistance in mungbean, explaining the phenotypic variance of 11.64%.

Powdery mildew resistance in soybean PI 243540 is controlled by a single dominant gene

2010 ◽  
Vol 90 (6) ◽  
pp. 939-942 ◽  
Author(s):  
S.-T. Kang ◽  
M.A. Rouf Mian
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Dominant Gene ◽  
Genetic Resistance ◽  
Segregation Ratio ◽  
Common Disease ◽  
Growth Stages ◽  
Single Dominant Gene ◽  
Sources Of Resistance ◽  
Mildew Resistance

Powdery mildew (Microsphaera diffusa Cooke & Peck) is a common disease of soybean in many countries of the world, including the northern United States of America and parts of Canada. The genetic resistance of soybean to M. diffusa is known to be controlled by a single locus with three alleles designated as Rmd, Rmd-c and rmd. Identification and characterization of sources of resistance is a prerequisite for the development of resistant cultivars. The objective of this study was to determine the inheritance of powdery mildew resistance in a plant introduction (PI) from Japan, PI 243540. The inheritance of powdery mildew was determined in a segregating population from a cross between powdery mildew susceptible Ohio cultivar Wyandot and PI 243540. The parents and the progeny showed a consistent response to powdery mildew for all growth stages of plants. The two parents, the F1, F2, and F2:3 families from the cross were screened in a greenhouse and field following inoculation with M. diffusa. All F1 plants were resistant to M. diffusa and χ2 analysis for segregation in the population of 343 F2 plants indicated a tight fit for a 3:1 (P = 0.78) ratio, indicative of a single dominant gene. In the next generation, the 334 F2-derived families fit an expected 1 resistant:2 segregating:1 susceptible segregation ratio (P =0.88), which confirmed the results obtained in the F2 generation. Our results indicate that the powdery mildew resistance derived from PI 243540 is controlled by a single dominant gene linked to the Rmd/ Rmd-c/rmd locus. The simple inheritance of this gene should make it relatively easy to find linked DNA markers and transfer the gene to susceptible elite cultivars using the backcross breeding approach.

scholarly journals Powdery mildew resistance of barley in Southern Dagestan

2021 ◽  
Vol 182 (1) ◽  
pp. 153-156
Author(s):  
B. A. Batasheva ◽  
R. A. Abdullaev ◽  
O. N. Kovaleva ◽  
I. A. Zveinek ◽  
E. E. Radchenko
Keyword(s):  
Powdery Mildew ◽  
Western Europe ◽  
Field Experiments ◽  
Powdery Mildew Resistance ◽  
Intraspecific Variability ◽  
Barley Plant ◽  
Southern Plains ◽  
Mildew Resistance ◽  
Long Term Study ◽  
High Level

Background.The most effective way of protecting crops from diseases and pests is the breeding and cultivation of resistant varieties. The hydrothermal regime in the southern plains of Dagest an favors damage to barley plant s by the causative agent of powdery mildew. The high level of disease progress observed annually helps to reliably assess the resistance of collection accessions to the pathogen.Materials and methods.The research material included 1361 barley accessions (570 improved cultivars and 791 landraces) of different ecogeographic origin and growth habit. Field experiments were launched concurrently with winter sowing. Powdery mildew resistance was scored during the heading period and in the milk ripeness phase using a point scale. Each accession was assessed for at least three years.Results and conclusions.The results of a long-term study disclosed a significant intraspecific variability of barley collection accessions in their resistance to powdery mildew. A significant part of the studied barley accessions (63.1%) appeared susceptible to the pathogen. The occurrence frequency of disease-resistant accessions was 11.0%, while those with medium resistance reached 25.9%. Among the landraces, four resistant accessions from the Abyssinian, West Asian and Mediterranean centers of crop origin were identified. Seventeen barley varieties resistant to powdery mildew (predominantly originated from Western Europe) are recommended for use in breeding for immunity.

scholarly journals Physiological Changes in Barley mlo-11 Powdery Mildew Resistance Conditioned by Tandem Repeat Copy Number

2020 ◽  
Vol 21 (22) ◽  
pp. 8769
Author(s):  
Cynthia Ge ◽  
Paula Moolhuijzen ◽  
Lee Hickey ◽  
Elzette Wentzel ◽  
Weiwei Deng ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Copy Number ◽  
Powdery Mildew Resistance ◽  
Binding Motif ◽  
Small Interfering Rnas ◽  
Mildew Resistance ◽  
Barley Powdery Mildew ◽  
Highly Expressed Genes ◽  
Normal Gene ◽  
High Level

Wild barley accessions have evolved broad-spectrum defence against barley powdery mildew through recessive mlo mutations. However, the mlo defence response is associated with deleterious phenotypes with a cost to yield and fertility, with implications for natural fitness and agricultural productivity. This research elucidates the mechanism behind a novel mlo allele, designated mlo-11(cnv2), which has a milder phenotype compared to standard mlo-11. Bisulphite sequencing and histone ChIP-seq analyses using near-isogenic lines showed pronounced repression of the Mlo promoter in standard mlo-11 compared to mlo-11(cnv2), with repression governed by 24 nt heterochromatic small interfering RNAs. The mlo-11(cnv2) allele appears to largely reduce the physiological effects of mlo while still endorsing a high level of powdery mildew resistance. RNA sequencing showed that this is achieved through only partly restricted expression of Mlo, allowing adequate temporal induction of defence genes during infection and expression close to wild-type Mlo levels in the absence of infection. The two mlo-11 alleles showed copy number proportionate oxidase and peroxidase expression levels during infection, but lower amino acid and aromatic compound biosynthesis compared to the null allele mlo-5. Examination of highly expressed genes revealed a common WRKY W-box binding motif (consensus ACCCGGGACTAAAGG) and a transcription factor more highly expressed in mlo-11 resistance. In conclusion, mlo-11(cnv2) appears to significantly mitigate the trade-off between mlo defence and normal gene expression.

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