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Leslie A. Wanner - One of the best experts on this subject based on the ideXlab platform.
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Cultivar Resistance to Common Scab Disease of Potato Is Dependent on the Pathogen Species.
Phytopathology, 2019Co-Authors: Christopher R. Clarke, Leslie A. Wanner, Charles G. Kramer, Raghavendhar R. Kotha, Devanand L. Luthria, Matthew KramerAbstract:Common Scab of potato is a superficial tuber disease caused by Streptomyces species that produce the phytotoxin thaxtomin. Because Common Scab development is highly dependent on the effects of this single toxin, the current operating paradigm in Common Scab pathology is that a potato cultivar resistant to one strain of the Common Scab pathogen is resistant to all strains. However, cultivar resistance to Common Scab disease identified in one breeding program is often not durable when tested in other potato breeding programs across the United States. We infected 55 potato cultivar populations with three distinct species of the Common Scab pathogen and identified cultivars that were resistant or susceptible to all three species and cultivars that had widely varying resistance dependent on the pathogen species. Overall lower virulence was associated with the strain that produces the least thaxtomin. This result showcases several cultivars of potato that are expected to be resistant to the majority of Common Scab populations but also highlights that many potato cultivars are resistant to only specific species of the pathogen. These results demonstrate that extension specialists and growers must consider their local population of the Common Scab pathogen when selecting which cultivars to plant for Common Scab resistance.
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multiplex real time pcr taqman assay for the simultaneous detection and discrimination of potato powdery and Common Scab diseases and pathogens
Journal of Applied Microbiology, 2011Co-Authors: Leslie A. Wanner, Barbara Jane ChristAbstract:Aims: To develop a multiplex real-time PCR assay using TaqMan probes for the simultaneous detection and discrimination of potato powdery Scab and Common Scab, two potato tuber diseases with similar symptoms, and the causal pathogens Spongospora subterranea and plant pathogenic Streptomyces spp. Methods and Results: Real-time PCR primers and a probe for S. subterranea were designed based on the DNA sequence of the ribosomal RNA ITS2 region. Primers and a probe for pathogenic Streptomyces were designed based on the DNA sequence of the txtAB genes. The two sets of primer pairs and probes were used in a single real-time PCR assay. The multiplex real-time PCR assay was confirmed to be specific for S. subterranea and pathogenic Streptomyces. The assay detected DNA quantities of 100 fg for each of the two pathogens and linear responses and high correlation coefficients between the amount of DNA and Ct values for each pathogen were achieved. The presence of two sets of primer pairs and probes and of plant extracts did not alter the sensitivity and efficiency of multiplex PCR amplification. Using the PCR assay, we could discriminate between powdery Scab and Common Scab tubers with similar symptoms. Common Scab and powdery Scab were detected in some tubers with no visible symptoms. Mixed infections of Common Scab and powdery Scab on single tubers were also revealed. Conclusions: This multiplex real-time PCR assay is a rapid, cost efficient, specific and sensitive tool for the simultaneous detection and discrimination of the two pathogens on infected potato tubers when visual symptoms are inconclusive or not present. Significance and Impact of the Study: Accurate and quick identification and discrimination of the cause of Scab diseases on potatoes will provide critical information to potato growers and researchers for disease management. This is important because management strategies for Common and powdery Scab diseases are very different.
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Multiplex real‐time PCR (TaqMan) assay for the simultaneous detection and discrimination of potato powdery and Common Scab diseases and pathogens
Journal of applied microbiology, 2011Co-Authors: Leslie A. Wanner, Barbara Jane ChristAbstract:Aims: To develop a multiplex real-time PCR assay using TaqMan probes for the simultaneous detection and discrimination of potato powdery Scab and Common Scab, two potato tuber diseases with similar symptoms, and the causal pathogens Spongospora subterranea and plant pathogenic Streptomyces spp. Methods and Results: Real-time PCR primers and a probe for S. subterranea were designed based on the DNA sequence of the ribosomal RNA ITS2 region. Primers and a probe for pathogenic Streptomyces were designed based on the DNA sequence of the txtAB genes. The two sets of primer pairs and probes were used in a single real-time PCR assay. The multiplex real-time PCR assay was confirmed to be specific for S. subterranea and pathogenic Streptomyces. The assay detected DNA quantities of 100 fg for each of the two pathogens and linear responses and high correlation coefficients between the amount of DNA and Ct values for each pathogen were achieved. The presence of two sets of primer pairs and probes and of plant extracts did not alter the sensitivity and efficiency of multiplex PCR amplification. Using the PCR assay, we could discriminate between powdery Scab and Common Scab tubers with similar symptoms. Common Scab and powdery Scab were detected in some tubers with no visible symptoms. Mixed infections of Common Scab and powdery Scab on single tubers were also revealed. Conclusions: This multiplex real-time PCR assay is a rapid, cost efficient, specific and sensitive tool for the simultaneous detection and discrimination of the two pathogens on infected potato tubers when visual symptoms are inconclusive or not present. Significance and Impact of the Study: Accurate and quick identification and discrimination of the cause of Scab diseases on potatoes will provide critical information to potato growers and researchers for disease management. This is important because management strategies for Common and powdery Scab diseases are very different.
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A Patchwork of Streptomyces Species Isolated from Potato Common Scab Lesions in North America
American Journal of Potato Research, 2009Co-Authors: Leslie A. WannerAbstract:To determine distribution and prevalence of Streptomyces species associated with Common Scab in North America, more than 1,400 isolates were made from Scabby potato tubers. Samples were obtained from locations across the continent, and from multiple sites in close geographic proximity. Most potentially pathogenic isolates belonged to four species previously associated with Common Scab, S. Scabies , S. europaeiScabiei , S. stelliScabiei , and S. sp. IdahoX. Additionally, small numbers of potentially pathogenic isolates were identified as S. acidiScabies , S. turgidiScabies and six additional ribotypes. S. europaeiScabiei was most Common in the west and S. Scabies predominated in the middle and eastern Midwest. Beyond this geographic trend, species distribution was patchy. A single species often predominated in a field while neighboring fields had different species. Local and regional variation was seen when isolates were genotyped for repetitive sequence element patterns, reflecting the conserved or core genome, and genes characteristic of the Streptomyces pathogenicity island, reflecting flexible components of the Streptomyces genome. This is the largest survey to date of the distribution of Common Scab-causing species, and will be a resource for population biology studies and for tracing the evolutionary history and spread of Common Scab-associated Streptomyces . Para determinar la distribución y prevalencia de especies de Streptomyces asociadas con la sarna común en Norteamérica, se hicieron más de 1,400 aislamientos de tubérculos de papa con sarna. Las muestras fueron obtenidas de localidades de todo el continente y de múltiples lugares geográficamente próximos. Los aislamientos potencialmente más patogénicos fueron de cuatro especies previamente asociadas con sarna común, S. Scabies, S. europaeiScabiei, S. stellicabiei y S. sp. IdahoX. Adicionalmente, un número pequeño de aislamientos potencialmente patogénicos fueron identificados como S. acidiScabies, S. turgidiScabies y seis ribotipos adicionales. S. europaeiScabiei fue el más común en el oeste y S. Scabies predominó en el centro y este del Medio Oeste. Más allá de esta tendencia geográfica, la distribución de especies fue en parches. Una sola especie a menudo predominó en un campo mientras en los campos vecinos se encontraron diferentes especies. Se vieron variaciones locales y regionales cuando a los aislamientos se les determinó el genotipo para patrones de elementos con secuencias repetitivas que reflejan el genoma conservado o central, y genes característicos de la isla de patogenicidad de Streptomyces , reflejando componentes flexibles del genoma de Streptomyces . Este es la pesquisa más extensa a la fecha sobre la distribución de las especies que causan sarna común, y será un recurso para estudios de biología poblacional y para determinar la historia evolutiva y diseminación de Streptomyces asociado a la sarna común.
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A Patchwork of Streptomyces Species Isolated from Potato Common Scab Lesions in North America
American Journal of Potato Research, 2009Co-Authors: Leslie A. WannerAbstract:To determine distribution and prevalence of Streptomyces species associated with Common Scab in North America, more than 1,400 isolates were made from Scabby potato tubers. Samples were obtained from locations across the continent, and from multiple sites in close geographic proximity. Most potentially pathogenic isolates belonged to four species previously associated with Common Scab, S. Scabies, S. europaeiScabiei, S. stelliScabiei, and S. sp. IdahoX. Additionally, small numbers of potentially pathogenic isolates were identified as S. acidiScabies, S. turgidiScabies and six additional ribotypes. S. europaeiScabiei was most Common in the west and S. Scabies predominated in the middle and eastern Midwest. Beyond this geographic trend, species distribution was patchy. A single species often predominated in a field while neighboring fields had different species. Local and regional variation was seen when isolates were genotyped for repetitive sequence element patterns, reflecting the conserved or core genome, and genes characteristic of the Streptomyces pathogenicity island, reflecting flexible components of the Streptomyces genome. This is the largest survey to date of the distribution of Common Scab-causing species, and will be a resource for population biology studies and for tracing the evolutionary history and spread of Common Scab-associated Streptomyces.
Calum R. Wilson - One of the best experts on this subject based on the ideXlab platform.
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Determining specific window period for Common Scab disease infection in potato tubers
Journal of Nepal Agricultural Research Council, 2017Co-Authors: Bhim Bahadur Khatri, Robert S. Tegg, Philip H. Brown, Calum R. WilsonAbstract:A series of experiments was conducted under glasshouse and hydroponic conditions to determine the specific window period for Common Scab disease infection in potato tubers. The study was performed in a glasshouse system where separate tubers from the root zone were inoculated at different intervals during plant growth along with a novel hydroponic system to inoculate individual tubers at specific times of development growth allowing non-destructive observations of Common Scab symptoms developing. The window of tuber susceptibility to Common Scab disease infection was shown to vary with the season or conditions under which the plants were grown. Different internodes on tubers were found susceptible to infection at different times during tuber development. Basal internodes, which are the first sections of the tuber to expand, were susceptible to infection in the beginning of tuber development, whereas apical internodes only became susceptible later in tuber growth when the basal internodes were no longer susceptible.
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Optimal rates of 2,4-dichlophenoxyacetic acid foliar application for control of Common Scab in potato
Annals of Applied Biology, 2014Co-Authors: Hk Thompson, Robert S. Tegg, Ross Corkrey, Calum R. WilsonAbstract:Applications of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) to the foliage of potato plants can reduce Common Scab, a tuber disease. However, in prior research effective applications at 200 mg L−1 2,4-D resulted in phytotoxic side effects with reduced tuber yield and quality. This study showed that minimal significant threshold rates from 8.3 to 23.6 mg L−1 2,4-D reduced disease incidence in pot trials, and from 10.8 to 41.0 mg L−1 minimised disease severity in both pot and field trials. In only one pot trial, significant phytotoxicity was found with rates of 100 mg L−1 or greater, reducing mean total tuber mass per plot and 38 mg L−1 or greater, reducing mean mass per tuber. Notably, within the field trial, a more reliable plant growth system for estimation of yield, no significant impacts were observed. Disease control was associated with decreased sensitivity of tubers to thaxtomin A, the phytotoxin produced by the Common Scab pathogen essential for disease induction. The amount of residual 2,4-D in tubers at harvest varied with cultivar, Russet Burbank accumulating more 2,4-D than Desiree. Application rates less than 100 mg L−1 resulted in levels of 2,4-D below the Australian standard maximum residue limit. These data suggest that applications of 2,4-D at low rates could provide a commercially suitable control strategy for Common Scab.
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Determination of optimal timing of 2,4-dichlorophenoxyacetic acid foliar applications for Common Scab control in potato
Annals of Applied Biology, 2013Co-Authors: Hk Thompson, Robert S. Tegg, Noel W. Davies, John Ross, Calum R. WilsonAbstract:Application of 2,4-dichlorophenoxyacetic acid (2,4-D) has been shown to be an effective control method for Common Scab of potato. Prior research targeted applications at or shortly after tuber initiation during the period of known susceptibility, with later treatment providing little or no control. This study examined the effect of a range of application dates and the influence of multiple applications at low and high rates on Common Scab control in both Russet Burbank and Desiree cultivars. We show that applications as early as 5 days after average plant emergence gave the greater disease control for both cultivars. These early treatments provide sufficient material to the tuber to induce resistance that lasts throughout the tuber susceptibility period with no requirement for, or benefit of repeated applications. Agronomic assessments suggested minor effects on total tuber mass produced with 2,4-D treatment but these were not consistent. Effective treatments result in levels of 2,4-D at harvest below the Australian maximum residue limit.
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In vitro cell selection techniques for enhancing disease resistance - case study: Common Scab resistance in Russet Burbank
Sustainable Potato Production: Global Case Studies, 2012Co-Authors: Calum R. Wilson, Robert S. TeggAbstract:Here we demonstrate the value of in vitro cell selection techniques for potato cultivar improvement using enhancement of Common Scab resistance as a case study. Common Scab is an important disease of potato world-wide. A diversity of Streptomyces species are associated with disease, however all pathogenic species and strains produce the phytotoxin, thaxtomin A. This toxin is an essential pathogenicity factor and provides a convenient positive selection agent for in vitro cell selection to obtain disease resistant potato variants. Using such techniques we obtained many variants of Russet Burbank with enhanced resistance to Common Scab, interestingly some of which did not express toxin tolerance. Agronomic assessments showed many variants had impaired yield, however several variants had equivalent or even superior yield to the unselected parent cultivar and these have been progressed toward commercial exploitation. Associated studies showed many of the Common Scab resistant variants showed resistance to a second unrelated disease, powdery Scab. Preliminary studies suggest altered suberisation within lenticels may be a possible mechanism for broad spectrum disease resistance to tuber-invading pathogens.
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Relationship Between the Application of Foliar Chemicals to Reduce Common Scab Disease of Potato and Correlation with Thaxtomin A Toxicity.
Plant disease, 2012Co-Authors: Robert S. Tegg, Ross Corkrey, Calum R. WilsonAbstract:Abstract Production of the phytotoxin thaxtomin A by pathogenic Streptomyces spp. is essential for induction of Common Scab disease in potato. The disease can be significantly reduced by a range of chemicals applied as foliar sprays before tuber initiation. We tested a range of chemicals that had previously demonstrated varying capacities to reduce Common Scab for both disease suppression and their ability to inhibit thaxtomin A toxicity in both ‘Desiree’ and ‘Russet Burbank’ potato. Our results for disease suppression generally supported previous studies. Our tuber slice assays with thaxtomin A showed a strong correlation between the ability of the chemical to suppress Common Scab symptom development and the ability of the chemical to inhibit thaxtomin A toxicity. A Bayesian measurement error linear regression model was derived for each cultivar and trial and demonstrated a clear positive relationship between disease and thaxtomin-A-induced necrosis. The relationships obtained were much stronger than wou...
Barbara Jane Christ - One of the best experts on this subject based on the ideXlab platform.
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multiplex real time pcr taqman assay for the simultaneous detection and discrimination of potato powdery and Common Scab diseases and pathogens
Journal of Applied Microbiology, 2011Co-Authors: Leslie A. Wanner, Barbara Jane ChristAbstract:Aims: To develop a multiplex real-time PCR assay using TaqMan probes for the simultaneous detection and discrimination of potato powdery Scab and Common Scab, two potato tuber diseases with similar symptoms, and the causal pathogens Spongospora subterranea and plant pathogenic Streptomyces spp. Methods and Results: Real-time PCR primers and a probe for S. subterranea were designed based on the DNA sequence of the ribosomal RNA ITS2 region. Primers and a probe for pathogenic Streptomyces were designed based on the DNA sequence of the txtAB genes. The two sets of primer pairs and probes were used in a single real-time PCR assay. The multiplex real-time PCR assay was confirmed to be specific for S. subterranea and pathogenic Streptomyces. The assay detected DNA quantities of 100 fg for each of the two pathogens and linear responses and high correlation coefficients between the amount of DNA and Ct values for each pathogen were achieved. The presence of two sets of primer pairs and probes and of plant extracts did not alter the sensitivity and efficiency of multiplex PCR amplification. Using the PCR assay, we could discriminate between powdery Scab and Common Scab tubers with similar symptoms. Common Scab and powdery Scab were detected in some tubers with no visible symptoms. Mixed infections of Common Scab and powdery Scab on single tubers were also revealed. Conclusions: This multiplex real-time PCR assay is a rapid, cost efficient, specific and sensitive tool for the simultaneous detection and discrimination of the two pathogens on infected potato tubers when visual symptoms are inconclusive or not present. Significance and Impact of the Study: Accurate and quick identification and discrimination of the cause of Scab diseases on potatoes will provide critical information to potato growers and researchers for disease management. This is important because management strategies for Common and powdery Scab diseases are very different.
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Multiplex real‐time PCR (TaqMan) assay for the simultaneous detection and discrimination of potato powdery and Common Scab diseases and pathogens
Journal of applied microbiology, 2011Co-Authors: Leslie A. Wanner, Barbara Jane ChristAbstract:Aims: To develop a multiplex real-time PCR assay using TaqMan probes for the simultaneous detection and discrimination of potato powdery Scab and Common Scab, two potato tuber diseases with similar symptoms, and the causal pathogens Spongospora subterranea and plant pathogenic Streptomyces spp. Methods and Results: Real-time PCR primers and a probe for S. subterranea were designed based on the DNA sequence of the ribosomal RNA ITS2 region. Primers and a probe for pathogenic Streptomyces were designed based on the DNA sequence of the txtAB genes. The two sets of primer pairs and probes were used in a single real-time PCR assay. The multiplex real-time PCR assay was confirmed to be specific for S. subterranea and pathogenic Streptomyces. The assay detected DNA quantities of 100 fg for each of the two pathogens and linear responses and high correlation coefficients between the amount of DNA and Ct values for each pathogen were achieved. The presence of two sets of primer pairs and probes and of plant extracts did not alter the sensitivity and efficiency of multiplex PCR amplification. Using the PCR assay, we could discriminate between powdery Scab and Common Scab tubers with similar symptoms. Common Scab and powdery Scab were detected in some tubers with no visible symptoms. Mixed infections of Common Scab and powdery Scab on single tubers were also revealed. Conclusions: This multiplex real-time PCR assay is a rapid, cost efficient, specific and sensitive tool for the simultaneous detection and discrimination of the two pathogens on infected potato tubers when visual symptoms are inconclusive or not present. Significance and Impact of the Study: Accurate and quick identification and discrimination of the cause of Scab diseases on potatoes will provide critical information to potato growers and researchers for disease management. This is important because management strategies for Common and powdery Scab diseases are very different.
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Heritability of Resistance to Common Scab in Diploid Potatoes
American Journal of Potato Research, 2009Co-Authors: Kathleen G. Haynes, Barbara Jane Christ, Christopher R. Burkhart, Bryan T. VinyardAbstract:Common Scab, caused by several species of Streptomyces, is a serious soil-borne disease of potatoes that may cause superficial, raised or pitted lesions on potato tubers. Little is known about the genetic basis of resistance to this disease. The purpose of this study was to determine if genetic resistance to Common Scab exists in a diploid Solanum phureja-S. stenotomum (phu-stn) population and to estimate broad-sense (H) and narrow-sense (h2) heritability for resistance to Common Scab. Two hundred seventy-one clones from a randomly mated phu-stn population were grown from 2003–2005 in naturally Streptomyces infested soil on a grower’s field in Northampton Co., PA, in a randomized complete block design replicated twice. After harvest, the proportion of tubers with Scab lesions was determined. The variable analyzed by the general linear models procedure in SAS using the maximum likelihood estimation method was the arcsine ( √ proportion of Scabby tubers). There were significant differences among clones and the year x clone interaction was significant. H for resistance was estimated as 0.18 with a 95% confidence interval of 0.15 to 0.35. The clonal source of variation was partitioned into among families and within families. All the variation occurred within families. There was no additive genetic variance for resistance in this population, hence, h2 was estimated as 0.00. Although levels of resistance to Common Scab cannot be improved by breeding in this diploid population, it may be feasible to transfer the high levels of resistance in this population to the tetraploid level via 4x-2x crosses.
Robert S. Tegg - One of the best experts on this subject based on the ideXlab platform.
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Determining specific window period for Common Scab disease infection in potato tubers
Journal of Nepal Agricultural Research Council, 2017Co-Authors: Bhim Bahadur Khatri, Robert S. Tegg, Philip H. Brown, Calum R. WilsonAbstract:A series of experiments was conducted under glasshouse and hydroponic conditions to determine the specific window period for Common Scab disease infection in potato tubers. The study was performed in a glasshouse system where separate tubers from the root zone were inoculated at different intervals during plant growth along with a novel hydroponic system to inoculate individual tubers at specific times of development growth allowing non-destructive observations of Common Scab symptoms developing. The window of tuber susceptibility to Common Scab disease infection was shown to vary with the season or conditions under which the plants were grown. Different internodes on tubers were found susceptible to infection at different times during tuber development. Basal internodes, which are the first sections of the tuber to expand, were susceptible to infection in the beginning of tuber development, whereas apical internodes only became susceptible later in tuber growth when the basal internodes were no longer susceptible.
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Optimal rates of 2,4-dichlophenoxyacetic acid foliar application for control of Common Scab in potato
Annals of Applied Biology, 2014Co-Authors: Hk Thompson, Robert S. Tegg, Ross Corkrey, Calum R. WilsonAbstract:Applications of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) to the foliage of potato plants can reduce Common Scab, a tuber disease. However, in prior research effective applications at 200 mg L−1 2,4-D resulted in phytotoxic side effects with reduced tuber yield and quality. This study showed that minimal significant threshold rates from 8.3 to 23.6 mg L−1 2,4-D reduced disease incidence in pot trials, and from 10.8 to 41.0 mg L−1 minimised disease severity in both pot and field trials. In only one pot trial, significant phytotoxicity was found with rates of 100 mg L−1 or greater, reducing mean total tuber mass per plot and 38 mg L−1 or greater, reducing mean mass per tuber. Notably, within the field trial, a more reliable plant growth system for estimation of yield, no significant impacts were observed. Disease control was associated with decreased sensitivity of tubers to thaxtomin A, the phytotoxin produced by the Common Scab pathogen essential for disease induction. The amount of residual 2,4-D in tubers at harvest varied with cultivar, Russet Burbank accumulating more 2,4-D than Desiree. Application rates less than 100 mg L−1 resulted in levels of 2,4-D below the Australian standard maximum residue limit. These data suggest that applications of 2,4-D at low rates could provide a commercially suitable control strategy for Common Scab.
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Determination of optimal timing of 2,4-dichlorophenoxyacetic acid foliar applications for Common Scab control in potato
Annals of Applied Biology, 2013Co-Authors: Hk Thompson, Robert S. Tegg, Noel W. Davies, John Ross, Calum R. WilsonAbstract:Application of 2,4-dichlorophenoxyacetic acid (2,4-D) has been shown to be an effective control method for Common Scab of potato. Prior research targeted applications at or shortly after tuber initiation during the period of known susceptibility, with later treatment providing little or no control. This study examined the effect of a range of application dates and the influence of multiple applications at low and high rates on Common Scab control in both Russet Burbank and Desiree cultivars. We show that applications as early as 5 days after average plant emergence gave the greater disease control for both cultivars. These early treatments provide sufficient material to the tuber to induce resistance that lasts throughout the tuber susceptibility period with no requirement for, or benefit of repeated applications. Agronomic assessments suggested minor effects on total tuber mass produced with 2,4-D treatment but these were not consistent. Effective treatments result in levels of 2,4-D at harvest below the Australian maximum residue limit.
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In vitro cell selection techniques for enhancing disease resistance - case study: Common Scab resistance in Russet Burbank
Sustainable Potato Production: Global Case Studies, 2012Co-Authors: Calum R. Wilson, Robert S. TeggAbstract:Here we demonstrate the value of in vitro cell selection techniques for potato cultivar improvement using enhancement of Common Scab resistance as a case study. Common Scab is an important disease of potato world-wide. A diversity of Streptomyces species are associated with disease, however all pathogenic species and strains produce the phytotoxin, thaxtomin A. This toxin is an essential pathogenicity factor and provides a convenient positive selection agent for in vitro cell selection to obtain disease resistant potato variants. Using such techniques we obtained many variants of Russet Burbank with enhanced resistance to Common Scab, interestingly some of which did not express toxin tolerance. Agronomic assessments showed many variants had impaired yield, however several variants had equivalent or even superior yield to the unselected parent cultivar and these have been progressed toward commercial exploitation. Associated studies showed many of the Common Scab resistant variants showed resistance to a second unrelated disease, powdery Scab. Preliminary studies suggest altered suberisation within lenticels may be a possible mechanism for broad spectrum disease resistance to tuber-invading pathogens.
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Relationship Between the Application of Foliar Chemicals to Reduce Common Scab Disease of Potato and Correlation with Thaxtomin A Toxicity.
Plant disease, 2012Co-Authors: Robert S. Tegg, Ross Corkrey, Calum R. WilsonAbstract:Abstract Production of the phytotoxin thaxtomin A by pathogenic Streptomyces spp. is essential for induction of Common Scab disease in potato. The disease can be significantly reduced by a range of chemicals applied as foliar sprays before tuber initiation. We tested a range of chemicals that had previously demonstrated varying capacities to reduce Common Scab for both disease suppression and their ability to inhibit thaxtomin A toxicity in both ‘Desiree’ and ‘Russet Burbank’ potato. Our results for disease suppression generally supported previous studies. Our tuber slice assays with thaxtomin A showed a strong correlation between the ability of the chemical to suppress Common Scab symptom development and the ability of the chemical to inhibit thaxtomin A toxicity. A Bayesian measurement error linear regression model was derived for each cultivar and trial and demonstrated a clear positive relationship between disease and thaxtomin-A-induced necrosis. The relationships obtained were much stronger than wou...
Craig G Yencho - One of the best experts on this subject based on the ideXlab platform.
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quantitative trait locus mapping for Common Scab resistance in a tetraploid potato full sib population
Plant Disease, 2021Co-Authors: Guilherme Da Silva Pereira, Kathleen G. Haynes, Marcelo Mollinari, Christian A Thill, Zhaobang Zeng, Craig G YenchoAbstract:Despite the negative impact of Common Scab (Streptomyces spp.) on the potato industry, little is known about the genetic architecture of resistance to this bacterial disease in the crop. We evaluated a mapping population (~150 full-sibs) derived from a cross between two tetraploid potatoes ('Atlantic' × B1829-5) in three environments (MN11, PA11, ME12) under natural Common Scab pressure. Three measures to Common Scab reaction, namely percentage of Scabby tubers, and disease area and lesion indices, were found to be highly correlated (>0.76). Due to the large environmental effect, heritability values were zero for all three traits in MN11, but moderate to high in PA11 and ME12 (0.44~0.79). We identified a single quantitative trait locus (QTL) for lesion index in PA11, ME12 and joint analyses on linkage group 3, explaining 22~30% of the total variation. The identification of QTL haplotypes and candidate genes contributing to disease resistance can support genomics-assisted breeding approaches in the crop.