scholarly journals Large-Scale Data Integration Reveals Colocalization of Gene Functional Groups with Meta-QTL for Multiple Disease Resistance in Barley

2011 ◽  
Vol 24 (12) ◽  
pp. 1492-1501 ◽  
Author(s):  
Patrick Schweizer ◽  
Nils Stein
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Data Integration ◽  
Functional Groups ◽  
Crop Production ◽  
Large Scale ◽  
Durable Resistance ◽  
Added Value ◽  
Powdery Mildew Fungus ◽  
Polygenic Inheritance

Race-nonspecific and durable resistance of plant genotypes to major pathogens is highly relevant for yield stability and sustainable crop production but difficult to handle in practice due to its polygenic inheritance by quantitative trait loci (QTL). As far as the underlying genes are concerned, very little is currently known in the most important crop plants such as the cereals. Here, we integrated publicly available data for barley (Hordeum vulgare subsp. vulgare) in order to detect the most important genomic regions for QTL-mediated resistance to a number of fungal pathogens and localize specific functional groups of genes within these regions. This identified 20 meta-QTL, including eight hot spots for resistance to multiple diseases that were distributed over all chromosomes. At least one meta-QTL region for resistance to the powdery mildew fungus Blumeria graminis was found to be co-linear between barley and wheat, suggesting partial evolutionary conservation. Large-scale genetic mapping revealed that functional groups of barley genes involved in secretory processes and cell-wall reinforcement were significantly over-represented within QTL for resistance to powdery mildew. Overall, the results demonstrate added value resulting from large-scale genetic and genomic data integration and may inform genomic-selection procedures for race-nonspecific and durable disease resistance in barley.

scholarly journals Evaluation of resistance to powdery mildew and identification of resistance genes in wheat cultivars

2020 ◽  
Author(s):  
Xian Xin Wu ◽  
Yue Gao ◽  
Qiang Bian ◽  
Qian Sun ◽  
Xin Yu Ni ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Large Scale ◽  
Durable Resistance ◽  
Cost Effective ◽  
Blumeria Graminis ◽  
Wheat Cultivars ◽  
Seedling Resistance ◽  
Initial Inoculum ◽  
Wheat Powdery Mildew

Abstract Background: Wheat powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici ( Bgt ), is a serious disease of wheat worldwide that can cause significant yield losses. Growing resistant cultivars is the most cost-effective and eco-soundly strategy to manage the disease. Therefore, a high breeding priority is to identify genes that can be readily used either singly or in combination for effective resistance to powdery mildew and alos in combination with genes for resistance to other diseases. Yunnan Province, with complex and diverse ecological environments and climates, is one of the main wheat growing regions in China. This region provides initial inoculum for starting epidemics of wheat powdery mildew in the region and other regions and thus, plays a key role in the regional and large-scale epidemics of the disease throughout China. The objectives of this study were to evaluate seedling resistance of 69 main wheat cultivars to powdery mildew and to determine the presence of resistance genes Pm3 , Pm8 , Pm13 , Pm16 , and Pm21 in these cultivars using gene specific DNA markers. Results: Evaluation of 69 wheat cultivars with six Bgt isolates showed that only four cultivars were resistant to all tested isolates, indicating that the overall level of powdery mildew resistance of Yunnan wheat cultivars is inadequate. The molecular marker results showed that 27 cultivars likely have at least one of these genes. Six cultivars were found likely to have Pm3 , 18 likely to have Pm8 , 5 likely to have Pm16 , and 3 likely to have Pm21 . No cultivar was found to carry Pm13 . Conclusion: The information on the presence of the Pm resistance genes in Yunnan wheat cultivars can be used in future wheat disease breeding programs. In particular, cultivars carrying Pm21 , which is effective against all Bgt races in China, should be pyramided with other effective genes to developing new cultivars with durable resistance to powdery mildew. Keywords: Blumeria graminis f. sp. tritici , Pm gene, molecular markers, wheat

scholarly journals The Ambivalence of the Barley Mlo Locus: Mutations Conferring Resistance Against Powdery Mildew (Blumeria graminis f. sp. hordei) Enhance Susceptibility to the Rice Blast Fungus Magnaporthe grisea

1999 ◽  
Vol 12 (6) ◽  
pp. 508-514 ◽  
Author(s):  
Birgit Jarosch ◽  
Karl-Heinz Kogel ◽  
Ulrich Schaffrath
Keyword(s):  
Powdery Mildew ◽  
Rice Blast ◽  
Magnaporthe Grisea ◽  
Durable Resistance ◽  
Rice Blast Fungus ◽  
Blumeria Graminis ◽  
Negative Regulator ◽  
Powdery Mildew Fungus ◽  
Mesophyll Cells ◽  
Blast Fungus

Recessive alleles of the barley Mlo locus confer non-race-specific resistance against the powdery mildew fungus Blumeria graminis f. sp. hordei (Bgh). Recently the Mlo gene has been isolated and it was suggested that the Mlo product is a negative regulator of cell death. Thus, loss of function can precondition cells to a higher responsiveness for the onset of multiple defense functions. Here, we document an enhanced susceptibility of barley mlo mutants to the rice blast fungus Magnaporthe grisea. The disease phenotype is independent of the barley cultivar in which the mlo allele has been introgressed and occurs in equal amounts in barley backcross lines of cv. Ingrid carrying the mlo-1, mlo-3, or mlo-5 allele. Ror genes, which are required for the full expression of mlo resistance in barley against Bgh, do not affect the specific mlo-mediated phenotype observed after M. grisea infection. Formation of an effective papilla restricts blast development in epidermal cells of Mlo plants. In contrast, papillae are mostly penetrated in mlo mutants and, as a consequence, the fungus spreads into adjacent mesophyll cells. Both wild-type plants and mlo mutants did not differ in perception of a purified elicitor derived from M. grisea. Thus, we hypothesize that a functional Mlo protein is a prerequisite for penetration resistance of barley to fungal pathogens like M. grisea. The benefit of mlo alleles for durable resistance in barley and a proposed role of mlo-type-mutations in rice are discussed.

scholarly journals Evaluation of resistance to powdery mildew and identification of resistance genes in wheat cultivars

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10425
Author(s):  
Xianxin Wu ◽  
Qiang Bian ◽  
Yue Gao ◽  
Xinyu Ni ◽  
Yanqiu Sun ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Large Scale ◽  
Durable Resistance ◽  
Cost Effective ◽  
Wheat Cultivars ◽  
Seedling Resistance ◽  
Initial Inoculum ◽  
Wheat Powdery Mildew ◽  
Serious Disease

Wheat powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), is a serious disease of wheat worldwide that can cause significant yield losses. Growing resistant cultivars is the most cost-effective and eco-soundly strategy to manage the disease. Therefore, a high breeding priority is to identify genes that can be readily used either singly or in combination for effective resistance to powdery mildew and also in combination with genes for resistance to other diseases. Yunnan Province, with complex and diverse ecological environments and climates, is one of the main wheat growing regions in China. This region provides initial inoculum for starting epidemics of wheat powdery mildew in the region and other regions and thus, plays a key role in the regional and large-scale epidemics of the disease throughout China. The objectives of this study were to evaluate seedling resistance of 69 main wheat cultivars to powdery mildew and to determine the presence of resistance genes Pm3, Pm8, Pm13, Pm16, and Pm21in these cultivars using gene specific DNA markers. Evaluation of 69 wheat cultivars with six Bgt isolates showed that only four cultivars were resistant to all tested isolates, indicating that the overall level of powdery mildew resistance of Yunnan wheat cultivars is inadequate. The molecular marker results showed that 27 cultivars likely have at least one of these genes. Six cultivars were found likely to have Pm3,18 likely to have Pm8,5 likely to have Pm16,and 3 likely to have Pm21. No cultivar was found to carry Pm13. The information on the presence of the Pmresistance genes in Yunnan wheat cultivars can be used in future wheat disease breeding programs. In particular, cultivars carrying Pm21, which is effective against all Bgtraces in China, should be pyramided with other effective genes to developing new cultivars with durable resistance to powdery mildew.

scholarly journals A Single Dominant Locus, Ren4, Confers Rapid Non-Race-Specific Resistance to Grapevine Powdery Mildew

2011 ◽  
Vol 101 (4) ◽  
pp. 502-508 ◽  
Author(s):  
David W. Ramming ◽  
Franka Gabler ◽  
Joe Smilanick ◽  
Molly Cadle-Davidson ◽  
Paola Barba ◽  
...  
Keyword(s):  
New York ◽  
Powdery Mildew ◽  
Natural Infection ◽  
Durable Resistance ◽  
Resistance Mechanism ◽  
Segregation Ratio ◽  
Powdery Mildew Fungus ◽  
Grapevine Powdery Mildew ◽  
Highly Correlated ◽  
Resistant Progeny

In the present study we screened the progeny of Vitis vinifera × V. romanetii populations segregating for resistance to powdery mildew and determined the presence of a single, dominant locus, Ren4, conferring rapid and extreme resistance to the grapevine powdery mildew fungus Erysiphe necator. In each of nine Ren4 pseudo-backcross 2 (pBC2) and pBC3 populations (1,030 progeny), resistance fit a 1:1 segregation ratio and overall segregated as 543 resistant progeny to 487 susceptible. In full-sib progeny, microscopic observations revealed the reduction of penetration success rate (as indicated by the emergence of secondary hyphae) from 86% in susceptible progeny to below 10% in resistant progeny. Similarly, extreme differences were seen macroscopically. Ratings for Ren4 pBC2 population 03-3004 screened using natural infection in a California vineyard and greenhouse and using artificial inoculation of an aggressive New York isolate were fully consistent among all three pathogen sources and environments. From 2006 to 2010, Ren4 pBC2 and pBC3 vines were continuously screened in California and New York (in the center of diversity for E. necator), and no sporulating colonies were observed. For population 03-3004, severity ratings on leaves, shoots, berries, and rachises were highly correlated (R2 = 0.875 to 0.996) in the vineyard. Together, these data document a powdery mildew resistance mechanism not previously described in the Vitaceae or elsewhere, in which a dominantly inherited resistance prevents hyphal emergence and is non-race-specific and tissue-independent. In addition to its role in breeding for durable resistance, Ren4 may provide mechanistic insights into the early events that enable powdery mildew infection.

scholarly journals Involvement of nonhost resistance genes in disease resistance plausible for future crop improvement

2019 ◽  
Author(s):  
Eram Sultan ◽  
Kalpana Dalei ◽  
Prashant Singh ◽  
Binod Bihari Sahu
Keyword(s):  
Disease Resistance ◽  
Broad Spectrum ◽  
Crop Production ◽  
Crop Improvement ◽  
Durable Resistance ◽  
Resistance Mechanisms ◽  
Phytophthora Sojae ◽  
Nonhost Resistance ◽  
R Genes ◽  
Disease Resistant

A plant species is infected by handful of pathogenic organism despite the fact that it is constantly exposed to innumerable pathogens. The chemical anti-bio agents exploited against these pathogens were harmful to environment and human health as well. So the only alternative way is to grow disease resistant varieties of crops by introducing resistant (R) genes. However, new pathogenic races evolve constantly and are notorious for their ability to withstand race specific resistance mediated by R-genes . Plants deploy robust, broad-spectrum and durable resistance mechanisms called nonhost resistance (NHR) against most pathogenic organisms. Such disease resistance mechanisms are nonspecific and effective against all nonhost or non-adaptive pathogens. The NHR defence response includes production of phytoalexins and other antimicrobial compounds, hypersensitive response by rapid localized cell death, deposition of callose and expression of pathogenesis related genes at the site of infection that restricts further growth of pathogen. Although NHR has immense potential to improve crop production in agriculture, very little is known about the mechanism of NHR and its genetic pathways at molecular level. Detail knowledge about the NHR genes from a nonhost plant and engineering the NHR gene into the host plant will be helpful in making broad-spectrum and durable disease resistant crops. In this mini review, we report the list of NHR genes and their function against various phytopathogens. We further report a method to identify or map putative NHR gene/s in Arabidopsis against soybean pathogen Phytophthora sojae nonhost with a goal to improve disease resistance in crop species.

scholarly journals Recognition Specificity and RAR1/SGT1 Dependence in Barley Mla Disease Resistance Genes to the Powdery Mildew Fungus

2003 ◽  
Vol 15 (3) ◽  
pp. 732-744 ◽  
Author(s):  
Qian-Hua Shen ◽  
Fasong Zhou ◽  
Stephane Bieri ◽  
Thomas Haizel ◽  
Ken Shirasu ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Resistance Genes ◽  
Disease Resistance Genes ◽  
Powdery Mildew Fungus ◽  
Recognition Specificity

scholarly journals Involvement of nonhost resistance genes in disease resistance plausible for future crop improvement

2019 ◽  
Author(s):  
Eram Sultan ◽  
Kalpana Dalei ◽  
Prashant Singh ◽  
Binod Bihari Sahu
Keyword(s):  
Disease Resistance ◽  
Broad Spectrum ◽  
Crop Production ◽  
Crop Improvement ◽  
Durable Resistance ◽  
Resistance Mechanisms ◽  
Phytophthora Sojae ◽  
Nonhost Resistance ◽  
R Genes ◽  
Disease Resistant

A plant species is infected by handful of pathogenic organism despite the fact that it is constantly exposed to innumerable pathogens. The chemical anti-bio agents exploited against these pathogens were harmful to environment and human health as well. So the only alternative way is to grow disease resistant varieties of crops by introducing resistant (R) genes. However, new pathogenic races evolve constantly and are notorious for their ability to withstand race specific resistance mediated by R-genes . Plants deploy robust, broad-spectrum and durable resistance mechanisms called nonhost resistance (NHR) against most pathogenic organisms. Such disease resistance mechanisms are nonspecific and effective against all nonhost or non-adaptive pathogens. The NHR defence response includes production of phytoalexins and other antimicrobial compounds, hypersensitive response by rapid localized cell death, deposition of callose and expression of pathogenesis related genes at the site of infection that restricts further growth of pathogen. Although NHR has immense potential to improve crop production in agriculture, very little is known about the mechanism of NHR and its genetic pathways at molecular level. Detail knowledge about the NHR genes from a nonhost plant and engineering the NHR gene into the host plant will be helpful in making broad-spectrum and durable disease resistant crops. In this mini review, we report the list of NHR genes and their function against various phytopathogens. We further report a method to identify or map putative NHR gene/s in Arabidopsis against soybean pathogen Phytophthora sojae nonhost with a goal to improve disease resistance in crop species.

scholarly journals Agricultural Technical Efficiency of Smallholder Farmers in Ethiopia: A Stochastic Frontier Approach

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 246
Author(s):  
Markose Chekol Zewdie ◽  
Michele Moretti ◽  
Daregot Berihun Tenessa ◽  
Zemen Ayalew Ayele ◽  
Jan Nyssen ◽  
...  
Keyword(s):  
Technical Efficiency ◽  
Crop Production ◽  
Large Scale ◽  
Positive Impact ◽  
Smallholder Farmers ◽  
Stochastic Frontier ◽  
Crop Productivity ◽  
Small Scale ◽  
Stochastic Frontier Approach ◽  
Small Scale Irrigation

In the past decade, to improve crop production and productivity, Ethiopia has embarked on an ambitious irrigation farming expansion program and has introduced new large- and small-scale irrigation initiatives. However, in Ethiopia, poverty remains a challenge, and crop productivity per unit area of land is very low. Literature on the technical efficiency (TE) of large-scale and small-scale irrigation user farmers as compared to the non-user farmers in Ethiopia is also limited. Investigating smallholder farmers’ TE level and its principal determinants is very important to increase crop production and productivity and to improve smallholder farmers’ livelihood and food security. Using 1026 household-level cross-section data, this study adopts a technology flexible stochastic frontier approach to examine agricultural TE of large-scale irrigation users, small-scale irrigation users and non-user farmers in Ethiopia. The results indicate that, due to poor extension services and old-style agronomic practices, the mean TE of farmers is very low (44.33%), implying that there is a wider room for increasing crop production in the study areas through increasing the TE of smallholder farmers without additional investment in novel agricultural technologies. Results also show that large-scale irrigation user farmers (21.05%) are less technically efficient than small-scale irrigation user farmers (60.29%). However, improving irrigation infrastructure shifts the frontier up and has a positive impact on smallholder farmers’ output.

scholarly journals Predicting Shifts in Land Suitability for Maize Cultivation Worldwide Due to Climate Change: A Modeling Approach

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 295
Author(s):  
Yuan Gao ◽  
Anyu Zhang ◽  
Yaojie Yue ◽  
Jing’ai Wang ◽  
Peng Su
Keyword(s):  
Climate Change ◽  
Crop Production ◽  
Large Scale ◽  
Land Suitability ◽  
Large Scale Assessment ◽  
Scale Assessment ◽  
Maize Cultivation ◽  
Large Scale Screening ◽  
Selection Of

Suitable land is an important prerequisite for crop cultivation and, given the prospect of climate change, it is essential to assess such suitability to minimize crop production risks and to ensure food security. Although a variety of methods to assess the suitability are available, a comprehensive, objective, and large-scale screening of environmental variables that influence the results—and therefore their accuracy—of these methods has rarely been explored. An approach to the selection of such variables is proposed and the criteria established for large-scale assessment of land, based on big data, for its suitability to maize (Zea mays L.) cultivation as a case study. The predicted suitability matched the past distribution of maize with an overall accuracy of 79% and a Kappa coefficient of 0.72. The land suitability for maize is likely to decrease markedly at low latitudes and even at mid latitudes. The total area suitable for maize globally and in most major maize-producing countries will decrease, the decrease being particularly steep in those regions optimally suited for maize at present. Compared with earlier research, the method proposed in the present paper is simple yet objective, comprehensive, and reliable for large-scale assessment. The findings of the study highlight the necessity of adopting relevant strategies to cope with the adverse impacts of climate change.

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