journal
MENU ▼
Read by QxMD icon Read
search

Phytopathology

journal
https://www.readbyqxmd.com/read/28517959/pomics-a-simulation-disease-model-for-timing-fungicide-applications-in-management-of-powdery-mildew-of-cucurbits
#1
Zaiton Sapak, Moin U Salam, Elizabeth J Minchinton, Garry P V MacManus, Daryl Joyce, Victor Joseph Galea
A weather-based simulation model, called POMICS, was constructed to predict fungicide application scheduling to manage powdery mildew of cucurbits. The model was developed on the principle that conditions favorable for Podosphaera xanthii, a causal pathogen of this crop disease, generate a number of infection cycles in a single growing season. The model consists of two components that: (i) simulate the disease progression of P. xanthii in secondary infection cycles under natural conditions and (ii) predict the disease severity with application of fungicides at any recurrent disease cycles...
May 18, 2017: Phytopathology
https://www.readbyqxmd.com/read/28513284/best-practices-for-population-genetic-analyses
#2
Niklaus J Grünwald, Sydney Everhart, Brian J Knaus, Zhian N Kamvar
Population genetic analysis is a powerful tool to understand how pathogens emerge and adapt. However, determining the genetic structure of populations requires complex knowledge on a range of subtle skills that are often not explicitly stated in book chapters or review articles on population genetics. What is a good sampling strategy? How many isolates should I sample? How do I include positive and negative controls in my molecular assays? What marker system should I use? This review will attempt to address many of these practical questions that are often not readily answered from reading books or reviews on the topic, but emerge from discussions with colleagues and from practical experience...
May 17, 2017: Phytopathology
https://www.readbyqxmd.com/read/28513283/molecular-characterisation-of-australian-isolates-of-puccinia-graminis-f-sp-tritici-supports-long-term-clonality-but-also-reveals-cryptic-genetic-variation
#3
Jianping Zhang, Peng Zhang, Haydar Karaoglu, Robert F Park
Long term surveys of pathogenicity in Puccinia graminis f. sp. tritici (Pgt) in Australia have implicated mutation as a major source of virulence, at times leading to the demise of stem rust resistant wheat cultivars and substantial yield losses. Since 1925, these surveys have identified at least four occasions on which exotic isolates of Pgt appeared in Australia, with each acting as a founding isolate that gave rise sequentially to derivative pathotypes via presumed single step mutation. The current study aimed to examine the relationship between virulence and molecular patterns using SSR markers on selected isolates of Pgt collected in Australia during a 52 year period in order to propose an evolutionary pathway...
May 17, 2017: Phytopathology
https://www.readbyqxmd.com/read/28504619/standard-area-diagrams-for-aiding-severity-estimation-scientometrics-pathosystems-and-methodological-trends-in-the-last-25-years
#4
Emerson Del Ponte, Sarah Jane Pethybridge, Clive Bock, Sami Jorge Michereff, Franklin Jackson Machado, Pierri Spolti
Standard area diagrams (SADs) have long been used as a tool to aid the estimation of plant disease severity, an essential variable in phytopathometry. Formal validation of SADs was not considered prior to the early 1990s, when considerable effort began to be invested developing SADs and assessing their value for improving accuracy of estimates of disease severity in many pathosystems. Peer-reviewed literature post-1990 was identified, selected and cataloged in bibliographic software for further scrutiny and extraction of scientometric, pathosystem- and methodological-related data...
May 15, 2017: Phytopathology
https://www.readbyqxmd.com/read/28414631/rathayibacter-toxicus-other-rathayibacter-species-inducing-bacterial-head-blight-of-grasses-and-the-potential-for-livestock-poisonings
#5
Timothy D Murray, Brenda K Schroeder, William L Schneider, Douglas G Luster, Aaron Sechler, Elizabeth E Rogers, Sergei A Subbotin
Rathayibacter toxicus, a Select Agent in the United States, is one of six recognized species in the genus Rathayibacter and the best known due to its association with annual ryegrass toxicity, which occurs only in parts of Australia. The Rathayibacter species are unusual among phytopathogenic bacteria in that they are transmitted by anguinid seed gall nematodes and produce extracellular polysaccharides in infected plants resulting in bacteriosis diseases with common names such as yellow slime and bacterial head blight...
May 15, 2017: Phytopathology
https://www.readbyqxmd.com/read/28475025/resistance-to-bean-common-mosaic-necrosis-virus-conferred-by-the-bc-1-gene-affects-systemic-spread-of-the-virus-in-common-bean
#6
Xue Feng, Pablo Guzmán, James R Myers, Alexander V Karasev
Bean common mosaic necrosis virus (BCMNV) isolates belong to two pathogroups (PG), PG-III and PG-VI, which are distinguished in common bean due to the inability of the PG-III isolates of BCMNV to overcome the two recessive resistance alleles bc-1 and bc-1(2). The biological and molecular basis of this distinction between PG-III and PG-VI isolates of BCMNV is not known. Here, three isolates of BCMNV were typed biologically on a set of 12 bean differentials and molecularly through whole-genome sequencing. Two isolates (1755b and TN1a) were assigned to PG-VI and one isolate (NL8-CA) was assigned to PG-III...
May 5, 2017: Phytopathology
https://www.readbyqxmd.com/read/28368237/assessment-of-the-virulence-spectrum-and-its-association-with-genetic-diversity-in-magnaporthe-oryzae-populations-from-sub-saharan-africa
#7
S K Mutiga, F Rotich, V Devi Ganeshan, D T Mwongera, E M Mgonja, V M Were, J W Harvey, B Zhou, L Wasilwa, C Feng, I Ouédraogo, G-L Wang, T K Mitchell, N J Talbot, J C Correll
A collection of 122 isolates of Magnaporthe oryzae, from nine sub-Saharan African countries, was assessed for virulence diversity and genetic relatedness. The virulence spectrum was assessed by pathotype analysis with a panel of 43 rice genotypes consisting of differential lines carrying 24 blast resistance genes (R-genes), contemporary African rice cultivars, and susceptible checks. The virulence spectrum among isolates ranged from 5 to 80%. Five isolates were avirulent to the entire rice panel, while two isolates were virulent to ∼75% of the panel...
May 5, 2017: Phytopathology
https://www.readbyqxmd.com/read/28471321/evaluation-of-probabilistic-disease-forecasts
#8
Gareth Hughes, Fiona Burnett
The statistical evaluation of probabilistic disease forecasts often involves calculation of metrics defined conditionally on disease status, such as sensitivity and specificity. However, for the purpose of disease management decision making, metrics defined conditionally on the result of the forecast - predictive values - are also important, although less frequently reported. In this context, the application of scoring rules in the evaluation of probabilistic disease forecasts is discussed. An index of separation with application in the evaluation of probabilistic disease forecasts, described in the clinical literature, is also considered and its relation to scoring rules illustrated...
May 4, 2017: Phytopathology
https://www.readbyqxmd.com/read/28323535/effector-gene-suites-in-some-soil-isolates-of-fusarium-oxysporum-are-not-sufficient-predictors-of-vascular-wilt-in-tomato
#9
Nicolas A Jelinski, Karen Broz, Wilfried Jonkers, Li-Jun Ma, H Corby Kistler
Seventy-four Fusarium oxysporum soil isolates were assayed for known effector genes present in an F. oxysporum f. sp. lycopersici race 3 tomato wilt strain (FOL MN-25) obtained from the same fields in Manatee County, Florida. Based on the presence or absence of these genes, four haplotypes were defined, two of which represented 96% of the surveyed isolates. These two most common effector haplotypes contained either all or none of the assayed race 3 effector genes. We hypothesized that soil isolates with all surveyed effector genes, similar to FOL MN-25, would be pathogenic toward tomato, whereas isolates lacking all effectors would be nonpathogenic...
May 4, 2017: Phytopathology
https://www.readbyqxmd.com/read/28453412/identification-and-characterization-of-citrus-tristeza-virus-isolates-breaking-resistance-in-trifoliate-orange-in-california
#10
Raymond K Yokomi, Vijayanandraj Selvaraj, Yogita Maheshwari, Maria Saponari, Annalisa Giampetruzzi, Michela Chiumenti, Subhas Hajeri
Most Citrus tristeza virus (CTV) isolates in California are biologically mild and symptomless in commercial cultivars on CTV tolerant rootstocks. However, to better define California CTV isolates showing divergent serological and genetic profiles, selected isolates were subjected to deep sequencing of small RNAs. Full-length sequences were assembled, annotated and trifoliate orange resistance-breaking (RB) isolates of CTV were identified. Phylogenetic relationships based on their full genomes placed three isolates in the RB clade: CA-RB-115, CA-RB-AT25, and CA-RB-AT35...
April 28, 2017: Phytopathology
https://www.readbyqxmd.com/read/28453406/crop-fertilisation-impacts-epidemics-and-optimal-latent-period-of-biotrophic-fungal-pathogens
#11
Pierre-Antoine Précigout, David Claessen, Corinne Robert
Crop pathogens are known to rapidly adapt to agricultural practices. Although cultivar resistance breakdown and resistance to pesticides have been broadly studied, little is known about the adaptation of crop pathogens to fertilization regimes and no epidemiological model has addressed that question. However this is a critical issue for developing sustainable low-input agriculture. In this paper, we use a model of life history evolution of biotrophic wheat fungal pathogens aiming to understand how they could adapt to changes in fertilization practices...
April 28, 2017: Phytopathology
https://www.readbyqxmd.com/read/28323536/on-social-and-political-effects-of-plant-pest-and-disease-epidemics
#12
J C Zadoks
Selected historical pest and disease outbreaks in the Old World are discussed in view of their social and political consequences. Large-scale epidemics always caused social unrest, and often hunger, pestilence, and death. When coming on top of deeply rooted and widely spread social unrest such epidemics contributed to political change. Examples are the revolts following epidemics in 1789 and 1846. Epidemics, regardless of causal and target organisms, have elements in common. The notion of a common concept grew into a firmly established discipline: epidemiology...
April 28, 2017: Phytopathology
https://www.readbyqxmd.com/read/28440700/selection-and-assessment-of-plant-growth-promoting-rhizobacteria-pgpr-for-biological-control-of-multiple-plant-diseases
#13
Ke Liu, Molli Newman, John A McInroy, Chia-Hui Hu, Joseph W Kloepper
A study was designed to screen individual strains of plant growth-promoting rhizobacteria (PGPR) for broad-spectrum disease suppression in vitro and in planta. In a preliminary screen, 28 of 196 strains inhibited eight different tested pathogens in vitro. In a secondary screen, these 28 strains showed broad spectrum antagonistic activity to six different genera of pathogens, and 24 of the 28 strains produced five traits reported to be related to plant growth promotion, including nitrogen fixation, phosphate solubilization, indole-3-acetic acid (IAA) production, siderophore production, and biofilm formation...
April 25, 2017: Phytopathology
https://www.readbyqxmd.com/read/28437139/protection-against-common-bean-rust-conferred-by-a-gene-silencing-method
#14
Bret Cooper, Kimberly B Campbell
Rust disease of the dry bean plant, Phaseolus vulgaris, is caused by the fungus Uromyces appendiculatus. The fungus acquires its nutrients and energy from bean leaves using a specialized cell structure, the haustorium, through which it secretes effector proteins that contribute to pathogenicity by defeating the plant immune system. Candidate effectors have been identified by DNA sequencing and motif analysis, and some candidates have been observed in infected leaves by mass spectrometry. To assess their roles in pathogenicity, we have inserted small fragments of genes for five candidates into bean pod mottle virus...
April 24, 2017: Phytopathology
https://www.readbyqxmd.com/read/28437138/epidemiology-of-basil-downy-mildew
#15
Yigal Cohen, Yariv Ben-Naim, Lidan Falach, Evgenia Rubin
Basil downy mildew (BDM) caused by the oomycete Peronospora belbahrii is a destructive disease of sweet basil (Ocimum basilicum) worldwide. It has originated in Uganda in the 1930's and recently spread to Europe, Middle East, Americas and the Far East. Seed transmission may be responsible to its quick global spread. The pathogen attacks leaf blades, producing chlorotic lesions with ample dark asexual spores on the lower leaf surface. Oospores may occur in the mesophyll of infected leaves. The asexual spores germinate on a wet leaf surface within 2h and penetrate into the epidermis within 4h...
April 24, 2017: Phytopathology
https://www.readbyqxmd.com/read/28430024/cacao-phylloplane-the-first-battlefield-against-moniliophthora-perniciosa-the-causal-agent-of-witches-broom-disease
#16
Dayanne Silva Monteiro Almeida, Karina Peres Gramacho, Thyago H Santana Cardoso, Fabienne Micheli, Fátima Cerqueira Alvim, Carlos Priminho Priminho Pirovani
The phylloplane is the first contact surface between Theobroma cacao and the fungus Moniliophthora perniciosa, which causes witches' broom disease (WBD). We evaluated the index of short glandular trichomes (SGTs) in the cacao phylloplane and the effect of irrigation on the disease index of cacao genotypes with/without resistance to WBD, and identified proteins present in the phylloplane. The resistant and susceptible genotype CCN51 and Catongo presented a mean index of 1600 and 700 SGTs•cm-2, respectively...
April 21, 2017: Phytopathology
https://www.readbyqxmd.com/read/28430023/harnessing-effector-triggered-immunity-for-durable-disease-resistance
#17
Meixiang Zhang, Gitta Coaker
Genetic control of plant diseases has traditionally included the deployment of single immune receptors with nucleotide-binding leucine-rich repeat (NLR) domain architecture. These NLRs recognize corresponding pathogen effector proteins inside plant cells, resulting in effector-triggered immunity (ETI). Although ETI triggers robust resistance, deployment of single NLRs can be rapidly overcome by pathogen populations within a single or a few growing seasons. In order to generate more durable disease resistance against devastating plant pathogens, a multi-tiered strategy that incorporates stacked NLRs combined with other sources of disease resistance is necessary...
April 21, 2017: Phytopathology
https://www.readbyqxmd.com/read/28430019/characterization-of-rph24-a-gene-conferring-adult-plant-resistance-to-puccinia-hordei-in-barley
#18
Laura A Ziems, Lee T Hickey, Gregory J Platz, Jerome D Franckowiak, Peter M Dracatos, Davinder Singh, Robert F Park
We identified Rph24 as a locus in barley (Hordeum vulgare L.) controlling adult plant resistance (APR) to leaf rust, caused by Puccinia hordei. The locus was previously reported as a quantitative trait locus in barley line ND24260-1 and named qRphND. We crossed ND24260-1 to the leaf-rust-susceptible standard Gus and determined inheritance patterns in the progeny. For the comparative marker frequency analysis (MFA), resistant and susceptible tails of the F2 were genotyped with Diversity Arrays Technology genotyping-by-sequencing (DArT-Seq) markers...
April 21, 2017: Phytopathology
https://www.readbyqxmd.com/read/28414633/genome-wide-analysis-provides-evidence-on-the-genetic-relatedness-of-the-emergent-xylella-fastidiosa-genotype-in-italy-to-isolates-from-central-america
#19
Annalisa Giampetruzzi, Maria Saponari, Giuliana Loconsole, Donato Boscia, Vito Nicola Savino, Rodrigo Almeida, Stefania Zicca, Blanca Landa, Carlos Chacon Diaz, Pasquale Saldarelli
Xylella fastidiosa is a plant pathogenic bacterium recently introduced in Europe that is causing decline in olive trees in the South of Italy. Genetic studies have consistently shown that the bacterial genotype recovered from infected olive trees belongs to the sequence type ST53 within subspecies pauca. This genotype, ST53, has also been reported to occur in Costa Rica. The ancestry of ST53 was recently clarified, showing it contains alleles which are monophyletic with those of subsp. pauca in South America...
April 17, 2017: Phytopathology
https://www.readbyqxmd.com/read/28414632/analysis-of-the-spatial-pattern-of-strawberry-angular-leaf-spot-in-california-nursery-production
#20
Christophe Gigot, William W Turechek, Neil McRoberts
In California, angular leaf spot (ALS) is a common disease in strawberry nursery production, and a major concern for nurseries wishing to export plants. As the spatial pattern of a disease can offer insight into pathogen source, mode of dissemination, and how current crop management practices affect epidemic development, an understanding of the spatial pattern of ALS would allow nursery growers to make informed decisions regarding disease management. Ninety seven field assessments of disease incidence were performed at different nursery locations in 2014 and 2015 to quantify ALS spatial pattern under commercial conditions...
April 17, 2017: Phytopathology
journal
journal
31861
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"