Download or read book Diversity and Virulence of Soybean Cyst Nematode Heterodera Glycines Ichinohe in Nebraska written by Kyle C. Broderick and published by . This book was released on 2016 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is one of the most economically important soybean pathogens in the United States. Best management practices are the use of resistant cultivars and crop rotation. Though there are several genetic sources of SCN resistance, most of the SCN-resistant cultivars are derived from a single resistance source (PI 88788). Other states have reported an increase in virulence to PI 88788 due to prolonged use of this resistance. In this thesis, two studies were conducted to characterize the diversity and virulent phenotypes of SCN populations in Nebraska. The first study assessed the virulent phenotypes of SCN field populations and their diversity in Nebraska by conducting HG type tests on 118 populations from 36 soybean-producing counties. 46.6%, 29.7%, and 88.1% of populations were virulent on PI 88788, Peking, and PI 548316 resistance respectively. No populations were virulent on PI 437654 (Hartwig). Virulence to PI 88788, PI 209332, and PI 548316 was common and found in nearly every county. Many counties also had populations virulent on Peking, PI 90763, and PI 89772. The second study investigated the mitochondrial diversity of SCN in Nebraska as well as the diversity within a field. Previous work examining the haplotype diversity of SCN using CO1 mitochondrial markers found low diversity and two primary haplotypes – one common and found throughout the U.S. while the second, the MNNE haplotype, was only found in Minnesota and northeast Nebraska. Markers were developed to determine if there is association of the MNNE haplotype with HG type and the incidence of the MNNE haplotype in Nebraska. No association was found between the MNNE haplotype and HG type. Populations from the original Nebraska field did not contain the MNNE haplotype, however it was confirmed to be in the original isolates suggesting the MNNE haplotype is found at very low frequencies in the field. Information on virulence and diversity of SCN in Nebraska will provide insight for development and selection of SCN resistant cultivars.
Download or read book Characterization of Soybean Cyst Nematode Diversity in Kansas written by Pamela Ann Rzodkiewicz and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The soybean cyst nematode (Heterodera glycines) (SCN) is an important pathogen of soybean in the United States. Annual yield losses from SCN are estimated to be over $2 billion worldwide. However, SCN virulence or the ability of a nematode to grow on resistant soybean genotypes varies widely among SCN populations. Fortunately there are several genetic sources of resistance to decrease the virulence of the pathogen on soybean. The objectives of this research were to: 1) characterize the genetic diversity of soybean cyst nematode populations in Kansas, 2) determine the frequency of Kansas SCN populations virulent on PI88788, 3) determine which plant introductions used in the HG Type Test provide the best level resistance, and 4) compare the performance of commercial soybean cultivars to the plant introduction from which their SCN resistance was derived. Soil samples were collected from SCN-infested fields across the state. Each soil sample was taken to the greenhouse and planted to a susceptible soybean cultivar to increase SCN population. Following an SCN population increase, a HG Type Test was planted. H. glycines field populations were highly variable, not only in population densities, but also in their abilities to develop on soybean genotypes. Collected from a diverse range of environments, ten HG types were identified. About 50% of the H. glycines populations were virulent on PI 88788, and most of the populations were virulent on commercial SCN resistant lines which derived their resistance from PI 88788. The commercial lines tended to be more susceptible to SCN than the lines from which they derived their resistance, but few HG populations were virulent on PI 437654 or the commercial line that derived its resistance from PI 437654. These results suggest that sources other than PI 88788 should be used in the development of H. glycines resistant cultivars for Kansas. One possible source of resistance is PI 437654. Information about SCN diversity in Kansas will improve decisions regarding cultivar development and selection for SCN management.
Download or read book Identifying the Genetic Determinants for Virulence in the Soybean Cyst Nematode Heterodera Glycines written by Dave T. Ste-Croix and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The soybean cyst nematode (SCN - Heterodera glycines) is the most economically important pathogen affecting soybean crops, causing significant reductions in yield on a global scale. Currently, the primary method for the management of this destructive root parasite is by utilizing natural host resistance. There are two main sources of genetic resistance commonly used in commercial practices to mitigate these losses: soybean plant introductions (PI) 548402 (Peking) and PI 88788. However, in North America, over 95% of resistant soybeans derive their resistance from PI 88788 genetics. Although still effective to a large extent, prolonged exposure to these limited genetic sources has led to the emergence of virulence within the SCN population, with subpopulations of nematodes now capable of overcoming host resistance. Given that soybean is expected to become one of the most economically significant grain crops in Quebec and Canada, it is crucial to understand how these nematodes overcome resistance. To gain insights into the genetic basis of virulence, a comparative transcriptomic analysis was conducted on individual nematodes isolated from multiple SCN populations with varying degrees of virulence against both main sources of resistance. By comparing the gene expression profiles of females categorized by their virulence phenotypes, we observed a significantly different transcriptomic response in females developing on Peking compared to those developing on PI 88788 or the susceptible control Essex. Indeed, overexpression and repression was observed in multiple effector genes of females developing on Peking. Further sequence analysis of expressed genes in Peking virulent nematodes also revealed a wide array of sequence polymorphisms and differential exon usage not shared by PI 88788 virulent or avirulent nematodes. Building upon the findings of potential alternative splicing in effector genes, a de-novo genome-guided transcriptome was generated in chapter two using long reads sequencing generated from single nematodes. This analysis aimed to assess the presence and extent of alternative splicing within effector genes and, more broadly, the SCN transcriptome. By comparing the expression profiles of these transcripts in PI 88788 virulent and avirulent females from different populations, simultaneously selected on both cultivars, two promising novel effector gene candidates (Hg-CPZ-1 and Hg16414.1) were identified, along with six other overexpressed effector candidates common to all virulent females from PI 88788. Although the two first chapters identified multiple candidate effectors associated with Peking and PI 88788 virulence, the regulatory mechanisms controlling these effectors remained unknown. Consequently, the third chapter explored the SCN microRNAs (miRNA) characterizing candidates potentially involved in the post-transcriptional regulation of effector genes. A comprehensive analysis of whole-nematodes and exosome-derived miRNAs revealed a diverse set of species- and lineage-specific candidates characterized for the first time in the SCN. By utilizing animal-specific and plant-specific miRNA target predictors, a subset of these miRNAs were also predicted to interact with nematode effectors and soybean resistance-related genes emphasizing the complex nature of SCN parasitism through the potential ability of nematodes to not only regulate its effectors genes but also its host genes. In summary, the findings from these chapters have not only enhanced our understanding of the mechanisms underlying the evolution and regulation of effector genes but also provide potential targets for improving resistance against SCN and detecting the presence of this destructive root parasite more effectively.
Download or read book Multifactorial Analysis of Mortality of Soybean Cyst Nematode Heterodera Glycines Ichinohe Populations in Soybean and in Soybean Fields Annually Rotated to Corn in Nebraska written by Oscar Pérez-Hernández and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The SCN Pf was modeled using an initial set of eight predictors. A negative binomial regression model with the log link function was applied to a 35-field training data set and a final model was selected. This model was used to estimate the nematode population density after annual corn rotation in the training data set and its prediction power was 82.1%. This predicting capability was confirmed in a validation data set in which the model's predicting capability was 79.6%.
Download or read book Identifying the genetic determinants for virulence in the soybean cyst nematode Heterodera glycines written by Dave Thibouthot-Ste-Croix and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Résumé en anglais
Download or read book Biology and Management of the Soybean Cyst Nematode written by Robert D. Riggs and published by American Phytopathological Society. This book was released on 1992 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1 History, distribution, and economics. 2 Systematics and morphology. 3 Epiphytology and life cycle. 4 Cellular responses to infection. 5 Population dynamics. 6 Genetics. 7 The race concept. 8 Nematode race identification, A look to the future. 9 Interactions with other organisms. 10 Host range. 11 Chemical control. 12 Management by cultural practices. 13 Biological control. 14 Breeding for resistance to soybean cyst nematode. 15 Cytopathological reactions of resistant soybean plants to nematode invasion. 16 Tolerance in soybean.
Download or read book Genetic and Molecular Analysis of Soybean Cyst Nematode Virulence written by Michael N. Gardner and published by . This book was released on 2017 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: The soybean cyst nematode (SCN) Heterodera glycines is the most economically important pathogen of soybean, capable of causing large scale yield loss on a global scale. Current management practices utilize host resistance, but commercial resistance is limited to three main sources, the soybean plant introductions (PI) 54802 (Peking), 88788, and 437654. More than 95% of soybean grown in the north central United States have resistance derived from PI 88788 and repeated use of this resistance has led to the development of highly virulent nematode populations capable of infecting these resistant plants and causing yield losses. In order to identify the mode of inheritance for virulence on the three primary sources of resistance to SCN a controlled crossing study was performed, mating a highly virulent nematode (TN20) with an avirulent nematode (PA3). By monitoring the offspring of this cross it was found that depending on the source of host resistance, virulence is inherited in a dominant or a recessive manner except for virulence on PI 437654, which is likely a multigenic trait dependent on multiple recessive genes. A de novo transcriptome assembly was then generated for SCN and mined for novel stylet-secreted effectors, identifying a new pool of candidates that may play a role in virulence. Finally, a comparative transcriptomic analysis was performed across multiple SCN populations to identify conserved expression patterns and genes associated with virulence. Results from these studies will be used to improve current management practices for SCN and provide new potential targets for improving SCN resistance.
Download or read book Cyst Nematodes written by Roland N Perry and published by CABI. This book was released on 2018-04-09 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a compendium of current information on all aspects of these economically important parasites. It provides comprehensive coverage of their biology, management, morphology and diagnostics, in addition to up-to-date information on molecular aspects of taxonomy, host-parasitic relationships and resistance. Written by a team of international experts, Cyst Nematodes will be invaluable to all researchers, lecturers and students in nematology, parasitology, agriculture and agronomy, industries with an interest in chemical and biological control products for management of plant-parasitic nematodes, and any courses, quarantine and advisory services.
Download or read book Multigenic and Induced Systemic Resistance in Plants written by Tuzun Sadik and published by Springer Science & Business Media. This book was released on 2006-10-26 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plants have developed very sophisticated mechanisms to combat pathogens and pestsusingtheleastamountofreservedorgeneratedenergypossible. Theydothis by activating major defense mechanisms after recognition of the organisms that are considered to be detrimental to their survival; therefore they have been able to exist on Earth longer than any other higher organisms. It has been known for the past century that plants carry genetic information for inherited resistance against many pathogenic organisms including fungi, bacteria, and viruses, and that the relationship between pathogenic organisms and hosts plants are rather complex and in some cases time dependent. This genetic information has been the basis for breeding for resistance that has been employed by plant breeders to develop better-yielding disease resistant varieties, some of which are still being cultivated. Single gene resistance is one type of resistance which has been extensively studied by many research groups all around the world using biotechnological methodologies that have been the subject of many books and journal articles; therefore, it is beyond the scope of this book. This type of resistance is very effective, although it can be overcome by the pressure of pathogenic organisms since it depends on interaction of a single elicitor molecule from the pathogen with a single receptor site in the host.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2002 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Systematics of Cyst Nematodes Nematoda Heteroderinae Part A written by Sergei A. Subbotin and published by BRILL. This book was released on 2010-08-23 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 8 in the series, appearing in two parts, A and B, deals with the systematics of cyst nematodes of the subfamily Heteroderinae. Cyst nematodes are important pathogens causing extensive damage and significant yield loss to many crops in both temperate and tropical regions. Part A presents summarised information on various aspects of morphology, biology, ecology, pathology, biogeography, control measures and diagnostics of these nematodes. Molecular diagnostic tables and comprehensive tabular and dichotomous keys for species identification, together with descriptions of protocols for extraction, light and electron microscopy studies, and molecular diagnostics are also included. The taxonomic section of part A provides diagnoses for six genera, viz., Globodera, Punctodera, Cactodera, Dolichodera, Betulodera and Paradolichodera, and includes descriptions and morphometrics of 30 valid species. The work is illustrated by 101 drawings and photos. The genus Heterodera is mainly covered in part B, complete descriptions and morphometrics of the 80 known valid species being provided and the species illustrated by 159 line drawings and photos. Identification of the species using morphological and molecular techniques is also covered. Each part includes an extensive bibliography.
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1973 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1974 with total page 1256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pest Management in Soybean written by L.G. Copping and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the third in a series of volumes on major tropical and sub-tropical crops. These books aim to review the current state of the art in management of the total spectrum of pests and diseases which affect these crops in each major growing area using a multi-disciplinary approach. Soybean is economically the most important legume in the world. It is nutritious and easily digested, and is one of the richest and cheapest sources of protein. It is currently vital for the sustenance of many people and it will play an integral role in any future attempts to relieve world hunger. Soybean seed contains about 17% of oil and about 63% of meal, half of which is protein. Modern research has developed a variety of uses for soybean oil. It is processed into margarine, shortening, mayonnaise, salad creams and vegetarian cheeses. Industrially it is used in resins, plastics, paints, adhesives, fertilisers, sizing for cloth, linoleum backing, fire extinguishing materials, printing inks and a variety of other products. Soybean meal is a high-protein meat substitute and is used in the developed countries in many processed foods, including baby foods, but mainly as a feed for livestock. Soybean (Glycine max), which evolved from Glycine ussuriensis, a wild legume native to northern China, has been known and used in China since the eleventh century Be. It was introduced into Europe in the eighteenth century and into the United States in 1804 as an ornamental garden plant in Philadelphia.
Download or read book Plant Parasitic Nematodes in Sustainable Agriculture of North America written by Sergei A. Subbotin and published by Springer. This book was released on 2018-12-17 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant-parasitic nematodes are recognized as one of the greatest threats to crop production throughout the world. Estimated annual crop losses of $8 billion in the United States and $78 billion worldwide are attributed to plant parasitic nematodes. Plant parasitic nematodes not only cause damage individually but form disease-complexes with other microorganisms thereby increasing crop loss. Nematode diseases of crops are difficult to control because of their insidious nature and lack of specific diagnostic symptoms which closely resemble those caused by other plant pathogens and abiotic diseases. Future developments of sustainable management systems for preventing major economical agricultural losses due to nematodes is focused on strategies that limit production costs, enhance crop yields, and protect the environment. This book presents a first compendium and overview for nematode problems and their management across North America. Each chapter provides essential information on the occurrence and distribution of plant parasitic nematodes, their major crop hosts, impact on crop production and sustainable management strategies for each region of the continent including, Canada, Mexico and all states of the USA. For each region, a thematic overview of changes in crop production affected by plant parasitic nematodes and their management strategies over time will provide invaluable information on the important role of plant parasitic nematodes in sustainable agriculture.
Download or read book Red Clover Science written by N.L. Taylor and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the literature on red clover since about 1985. In each of the 17 chapters, an effort was made to summarize the earlier literature and to integrate the recent findings into this background. The timing is appropriate with the present interest in sustainable agriculture, in which red clover was so prominent in the past. This is the first book to be published which deals solely with this important forage species. Audience: Primarily scientists and scientifically trained technicians who will appreciate an up-to-date summary on red clover.
Download or read book Management of Phytonematodes Recent Advances and Future Challenges written by Rizwan Ali Ansari and published by Springer Nature. This book was released on 2020-06-29 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book illustrates the currently available strategies for managing phytonematodes. It discusses the latest findings on plant-pathogen-microbiome interactions and their impacts on ecosystems, and provides extensive information on the application of microorganisms in the sustainable management of phytonematodes. This is followed by an in-depth discussion of the application of potential strains of biocontrol fungi, endophytes and actinomycetes to enhance plants’ ability to fend off phytonematode attacks, leading to improved plant health. In conclusion, the book addresses new aspects like the biofabrication of nanoparticles and their application in plant disease management, and presents an extensive list for further reading.
