Download or read book Studies of Fusarium Virguliforme Causing Sudden Death Syndrome of Soybean written by Ramiz Mahdi Salih Alabdalsaid and published by . This book was released on 2021 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fusarium virguliforme is one of the important pathogens on soybeans, and it is a soil borne pathogen. This pathogen causes sudden death syndrome on soybean (SDS). The fungus remains in the soil or on the plant residues for many years in the form of chlamydospores. When the appropriate conditions are available for the infection, the pathogen penetrates the soybean's roots and causes symptoms on the roots that appear in the form of reddish-brown, discoloration and necrosis. On the leaves the symptoms appear in the form of irregular spots shape. In the development of the infection the fall of leaves, abortion of flowers and pods occur. Due to the economic importance of the disease and the fungus that causes it. This study conducted to gain more information and understand the behavior of the pathogen. The results study of the effect of some culture media, pH and nitrogen sources on F. virguliforme growth in vitro showed that the pathogen has able to grow on all culture media that used. on culture media Czapek Dox agar (CDA) and Malt Extract Agar (MEA), the F. virguliforme was grown fast to cover plate in 8 days of incubation. Potato Sucrose Agar (PSA) and Malt Extract Agar (MEA) were the best culture media for fungal sporulation while the lowest number of spores was on Glucose yeast peptone Agar (GYPA). Also, the study showed the best pH for radial growth was 7 at 20, 25 and 30 C. But the radial growth of Fungus was slow at pH 10. The fungal sporulation at pH 6 was good comparing to fungal sporulation at pH 10 which was less. The radial growth of fungus was affected by different nitrogen sources and concentration. In general, the ammonium sulphate was not suitable for fungal radial growth and The best fungal sporulation was on media with peptone 2 g comparing with other nitrogen sources. In the second chapter, the results of histopathology of roots for two soybean varieties infected by F. virguliforme showed that the pathogen uses the same strategy to attack the roots of soybean varieties, penetration and colonization. The pathogen can grow intercellular and intracellular. During infection the pathogen causes damage to the root cells. Accumulating of materials inside root's cells because pathogen invasion. The last chapter in this study is, effect light on F. virguliforme growth. The study showed that the radial growth of the fungus was the maximum under continuous darkness comparing to fungal radial growth under light/dark cycle 12/12 LD, 16/8 LD and 18/6 LD. In addition to that colorful bands were formed when the fungus grew under under light/dark cycle. The results showed the ability of pathogen to cause Lesion on soybean stems under light/dark cycle. Also, using two inoculum 105, 106 of pathogen to test it pathogenicity on soybean roots showed no significant differences.

Download or read book Isolation and Characterization of a Fusarium Virguliforme Toxin that Induces Foliar Sudden Death Syndrome in Soybean Glycine Max L Merr written by Hargeet Kaur Brar and published by . This book was released on 2010 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification and Characterization of Pathogenicity Genes in Fusarium Virguliforme the Causal Agent of Sudden Death Syndrome SDS in Soybean written by Saara Mansouri and published by . This book was released on 2012 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fusarium virguliforme is a soil-borne pathogen that causes sudden death syndrome (SDS) disease in soybean. SDS is one of the most significant diseases of soybean in the United States. Fungal infection results in root and crown rot as well as SDS typical foliar symptoms including chlorosis, necrosis and complete defoliation. The use of soybean cultivars tolerant to SDS is still the most effective way to overcome the disease. On the other hand, the fungal isolates are known to have varied levels of aggressiveness on soybean indicated by the field and greenhouse experiments. Understanding the pathogen and its defense mechanism is the first step in exploring the pathogen-plant interaction. Therefore, the primary aim of this research was to elucidate the mechanism behind F. virguliforme response to soybean defense mechanisms. We further attempted to identify chromosome length polymorphism among F. virguliforme isolates and characterize the possible relationship to their level of aggressiveness. The findings are instrumental in identifying novel pathogenicity such as the ones involved in phytotoxin production, fungicide resistance and aggressiveness.

Download or read book Developing Novel Molecular Tools to Study the Fusarium Virguliforme soybean Interaction written by Saara Mansouri and published by . This book was released on 2007 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fusarium virguliforme is a soil-borne pathogen that causes Sudden Death Syndrome (SDS) in soybeans. Since the use of resistant varieties is still the most effective way to combat the disease, the need to develop new molecular tools to study the interaction between the fungus and the plant is required. To reach this goal, we have developed a protoplast based fungal transformation system for F. virguliforme. One of the applications of the transformation system was the production of a green fluorescent protein (GFP)-expressing fungal transformant. The GFP-expressing fungus can be used to study the fungal infection process including fungal penetration, colonization, and spread, especially at the early stages of disease development. Furthermore, in an attempt to increase the genetic resources available to identify and characterize fungal virulence genes involved in the F. virguliforme-soybean system, we generated random insertional mutations in F. virguliforme using Restriction Enzyme Mediated Integration (REMI).

Download or read book Molecular Quantification and Carbon Source Utilization of Fusarium Virguliforme the Causal Agent of Soybean Sudden Death Syndrome written by Eugenia Tang and published by . This book was released on 2008 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification and Characterizations of Pathogenicity Genes in Fusarium Virguliforme the Causal Agent of Soybean Sudden Death Syndrome SDS written by Kazi Tariqul Islam and published by . This book was released on 2015 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification of Phytotoxins Produced by Fusarium Virguliforme Associated with Foliar Symptoms of Sudden Death Syndrome and Genome wide Association Studies for Soybean Disease Resistance written by Hao-Xun Chang and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigating Management and Genetics of Soybean Sudden Death Syndrome Pathogens Fusarium Virguliforme and F Brasiliense written by Mitchell G. Roth and published by . This book was released on 2019 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annual soybean production in the U.S. is worth nearly $40 billion, valued for its oils and protein content. Many pathogens and pests cause significant soybean yield losses each year, but one of the top threats is sudden death syndrome (SDS). At least five fungal species cause soybean SDS globally, but only two have been found in the U.S.; Fusarium virguliforme and F. brasiliense. These soil-borne pathogens infect root tissues and cause root rot, with continued infection leading to foliar interveinal chlorosis, interveinal necrosis, leaf drop, and yield loss. The pathogens are strong saprophytes that can overwinter in soybean and corn residue, so successful management is difficult. Long-term crop rotations and seed treatments with fungicides show some efficacy, but these strategies can be costly for growers. Growers desire genetic resistance to SDS, but no soybean germplasm has shown 100% resistance to SDS to date. Therefore, the overall goals of projects presented in this dissertation were to help improve SDS management and explore the biology and genetics of F. virguliforme and F. brasiliense. To achieve these goals, I developed a risk prediction tool for integration with current SDS management strategies (Chapter 2). This study revealed that pathogen data collected from soil at-planting can be used to accurately model spatial distributions pathogens and model future SDS development and yield loss at a field level. This risk prediction study used a qPCR assay specific for F. virguliforme, but a similar qPCR assay for F. brasiliense did not exist. Therefore, I developed a qPCR assay that can distinguish F. brasiliense from close relatives (Chapter 3). This tool that can be used to generate SDS-prediction models for F. brasiliense and I predict will be valuable in diagnostic labs across the country to distinguish between these two species. To advance our understanding of the biology and genetics of these pathogens, I developed a new protoplast generation and transformation method to generate fluorescent strains of each pathogen (Chapter 4). This chapter is the first to report genetic transformation in F. brasiliense. Furthermore, I used the fluorescent strains to investigate the synergistic role of soil-borne nematodes in SDS (Chapter 5). The interactions between these fungal pathogens and nematodes in vitro show that F. virguliforme and F. brasiliense can colonize immobile nematodes, but suggest that they are not actively vectored into soybean roots by nematodes. The genetic mechanisms of SDS development are poorly understood, so I developed high quality genome sequences for F. virguliforme and F. brasiliense (Chapter 6) and investigated two recognized effector proteins; FvTox1 and FvNIS1 (Chapter 7). The genome assemblies developed here have significantly improved continuity, with improved genome assembly metrics like contig length (N50) and contig number. However, whole-genome alignments between F. virguliforme and F. brasiliense from soybean (Glycine max) or dry bean (Phaseolus vulgaris) did not reveal obvious mobile pathogenicity chromosomes that have been observed in the close relative F. oxysporum. However, these genome resources should facilitate discovery of new fungal effector proteins like FvTox1 and FvNIS1. Interestingly, my results show that FvNIS1 is able to induce a hypersensitive response in tobacco, while FvTox1 is not, suggesting a conserved mechanism between soybean and tobacco for FvNIS1 recognition. Overall, this work provides valuable tools for managing and studying SDS-causing fungi, while also revealing insights into the genetics and genomics of the SDS-causing pathogens F. virguliforme and F. brasiliense.

Download or read book Impact of Arbuscular Mycorrhizas on Sustainable Agriculture and Natural Ecosystems written by Silvio Gianiazzi and published by Birkhäuser. This book was released on 2012-12-06 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, prepared by participants of the European network COST ACTION 810 (1989-93) is the outcome of a meeting held in Switzerland (Einsiedeln, September 29 to October 2, 1993) on the "Impact of arbuscular mycorrhizas on sustainable agriculture and natural ecosystems". COST(Cooperation Scientifique et Technique) Networks were created in 1971 by the Commission of European Communities, and later enlarged to include non-European Member States, to promote pre-competitive scientific and technical research in fields of common interest. During the eighties, COST ACTIONS were launched in bio technological fields, including the network on arbuscular mycorrhizas. Arbuscular mycorrhizas are a universally found symbiosis between plants and certain soil fungi and essential components of soil-plant systems. They act as a major inter face by influencing or regulating resource allocation between abiotic and biotic components of the soil-plant system. Arbuscular mycorrhizas are involved in many key ecosystem processes including nutrient cycling and conservation of soil struc ture, and have been shown to improve plant health through increased protection against abiotic and biotic stresses. Sustainability can be defined as the successful management of resources to satisfy changing human needs while maintaining or enhancing the quality of the environ ment and conserving resources. Increasing environmental degradation and instability, due to anthropogenic activities and in particular the increasing fragility of the soil resource, has led to an increased awareness of the need to develop practices resulting in more sustainable natural and agroecosystems.

Download or read book Optimizing Conditions for Production of Toxin Culture Filtrate of Fusarium Virguliforme Comparing Isolates Causing Sudden Death Syndrome and the Use of Soy Milk to Culture Soybean Pathogens written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Fusarium Laboratory Manual written by John F. Leslie and published by John Wiley & Sons. This book was released on 2008-02-28 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the first time in over 20 years, a comprehensive collection of photographs and descriptions of species in the fungal genus Fusarium is available. This laboratory manual provides an overview of the biology of Fusarium and the techniques involved in the isolation, identification and characterization of individual species and the populations in which they occur. It is the first time that genetic, morphological and molecular approaches have been incorporated into a volume devoted to Fusarium identification. The authors include descriptions of species, both new and old, and provide protocols for genetic, morphological and molecular identification techniques. The Fusarium Laboratory Manual also includes some of the evolutionary biology and population genetics thinking that has begun to inform the understanding of agriculturally important fungal pathogens. In addition to practical “how-to” protocols it also provides guidance in formulating questions and obtaining answers about this very important group of fungi. The need for as many different techniques as possible to be used in the identification and characterization process has never been greater. These approaches have applications to fungi other than those in the genus Fusarium. This volume presents an introduction to the genus Fusarium, the toxins these fungi produce and the diseases they can cause. "The Fusarium Laboratory Manual is a milestone in the study of the genus Fusarium and will help bridge the gap between morphological and phylogenetic taxonomy. It will be used by everybody dealing with Fusarium in the Third Millenium." --W.F.O. Marasas, Medical Research Council, South Africa

Download or read book Response of Fusarium Solani to Fluctuating Temperatures written by Keith F. Jensen and published by . This book was released on 1971 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Host Range of Fusarium Virguliforme on Rotational Crops and Common Plant Species and Its Survival and Growth on Crop Residue written by Tammy Mae Kolander and published by . This book was released on 2010 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Fungicide Seed Treatments on Fusarium Virguliforme and Development of Sudden Death Syndrome in Soybean written by Japheth D. Weems and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sudden death syndrome (SDS) is a soilborne disease responsible for causing significant yield reductions across soybean-producing states. Recent research indicates that infection of the soybean radicle early in the season by Fusarium virguliforme (Fv), the SDS pathogen, is critical for disease development. This suggests fungicide seed treatments could be effective in limiting early infection possibly resulting in disease control. Field, greenhouse, and laboratory studies were conducted to evaluate eight fungicides in multiple seed treatment combinations for effects on Fv infection and SDS development. Seed treatments were applied to cultivars that were moderately resistant and moderately susceptible to SDS. Field studies were conducted at two locations: in 2008, the Valmeyer, IL location was naturally infested with Fv, and in 2008 and 2009 the Urbana, IL location had a natural Fv infestation and soil was augmented with sterilized grain sorghum colonized by Fv. Similarly, the greenhouse study was inoculated with sterilized, Fv infested grain sorghum to evaluate the same seed treatments on moderately resistant and moderately susceptible cultivars. The rolled-paper towel laboratory assay tested the individual fungicides in the growth chamber using a Fv macroconidial suspension to inoculate treated seed and assess effects on seed germination, plant length, lesion size, and disease severity. Fv DNA concentrations in soybean roots were measured using quantitative polymerase chain reaction (qPCR) in early vegetative stage roots. Soybean roots from the field were collected at three timings for digital scanning and analysis with root analysis software to measure root disease symptoms. Roots were scanned and analyzed at the completion of the greenhouse trial. SDS foliar symptoms were rated several times throughout plant growth and the area under disease progress curve (AUDPC) was calculated. Harvest data were collected for the field study. In the field, seed treatments had no effect on Fv DNA concentrations in roots. Seed treatments had very little effect on roots analyzed from the field. Most seed treatments did significantly decrease SDS foliar symptoms at the Valmeyer field study compared to the control, but no differences in foliar symptoms were observed for the Urbana field studies. Yield was unaffected by seed treatments. In the greenhouse, Fv DNA concentrations were reduced by a treatment combining mefenoxam + thiophanate-methyl + azoxystrobin + B. pumilus + prothioconazole + fludioxonil compared to the non-treated control; however, the reduction in Fv DNA did not improve root growth or decrease SDS foliar symptoms compared to the non-treated control. The Fv DNA concentrations in roots did not significantly correlate to SDS foliar symptoms in the field; however, a significant positive correlation was found in the greenhouse between Fv DNA and SDS foliar symptoms. Several seed treatments decreased lesion length and disease severity compared to the non-treated inoculated control in the rolled-towel laboratory assay, but the biological seed treatment, B. pumilus, significantly decreased seed germination and plant length while increasing lesion length and SDS severity compared to the non-treated inoculated control. In conclusion, none of the seed treatments evaluated proved to have consistent effects on Fv or SDS.

Download or read book Molecular Diagnostics Epidemiology and Population Genetics of the Soybean Sudden Death Syndrome Pathogen Fusarium Virguliforme written by Jie Wang and published by . This book was released on 2016 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Insights of Chemical Cultural and Genetic Exploration for Soybean Sudden Death Syndrome Management and Fusarium Virguliforme written by Amy Marie Baetsen-Young and published by . This book was released on 2019 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soybean sudden death syndrome, caused by Fusarium virguliforme, is a key limitation in reaching soybean (Glycine max) yield potential, stemming from limited disease management through cultural practices and partial host resistance. The research within this thesis reveals the economic potential of fungicide seed treatment SDS fluopyram to alleviate yield loss, provides insights into field management of F. virguliforme and highlights transcriptomic plasticity of diverse host-fungal interactions. Previously, farm level studies have found the fungicide seed treatment of fluopyram profitable, yet the benefit across an aggregate level of soybean production at risk to SDS yield loss is unknown. To estimate economic benefits of fluopyram adoption in SDS at risk acres, in the light of U.S public research and outreach costs, an economic surplus approach was applied to calculate ex ante net benefits from 2018 to 2032. Through this framework of fluopyram adoption for alleviation of SDS associated yield losses, we estimated a net benefit of $5,829 million over 15 years, considering public seed treatment research costs from 2014 to present and future extension communication. While chemical seed treatments aid disease management of SDS, the ability of this pathogen to colonize asymptomatic hosts may increase the prevalence of F. virguliforme. Thus, the impact of cultural tactics upon F. virguliforme colonization of an asymptomatic host, and the ability of this colonization to alter subsequent SDS symptoms when rotated to soybean were explored. The exploration of tillage, and residue management across four U.S. states provided clarity to variable reports, revealing that no-tillage inconsistently enhances F. virguliforme colonization of corn and soybean roots, while corn residue did not alter pathogen colonization. Alternatively, an asymptomatic host provides a unique application to discover genetic factors facilitating soybean sudden death syndrome through investigation host-fungal interactions. Exploring this plant disease through a comparative orthologous mRNA-Seq on soybean and corn hosts under colonization of F. virguliforme uncovered transcriptional responses enabling a robust defense response in corn, and delayed immune induction within soybean permitting pathogenic colonization and susceptibility. To colonize both hosts, F. virguliforme exhibited a massive transcriptional rewiring of an infection program. Transcriptomic responses suggest, F. virguliforme is less suited for colonization of monocots by delayed colonization, and lower induction of CAZymes and effector proteins. Integration of the data generated through the mRNA-Seq experiments, including a micro-like RNA-Seq analysis of soybean host during colonization by F. virguliforme revealed an intimate communication between the plant and fungal pathogen; we posit that a micro-like RNA cross-talk potentially regulates host susceptibility. Overall, several hypotheses were generated surrounding hemibiotrophic enhancement of host senescence, and fungal ecological plasticity through transcriptomic reprogramming, which will deliver transparency upon a currently difficult and enigmatic syndrome.

Download or read book The Existence of Fusarium Solani F Phaseoli in Nature written by Shirley Mae Nash and published by . This book was released on 1962 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: