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Global Distribution And Richness Of Armillaria And Related Species Inferred From Public Databases And Amplicon Sequencing Datasets, Rachel A. Koch, Joshua Herr Nov 2021

Global Distribution And Richness Of Armillaria And Related Species Inferred From Public Databases And Amplicon Sequencing Datasets, Rachel A. Koch, Joshua Herr

Department of Plant Pathology: Faculty Publications

Armillaria is a globally distributed fungal genus most notably composed of economically important plant pathogens that are found predominantly in forest and agronomic systems. The genus sensulato has more recently received attention for its role in woody plant decomposition and in mycorrhizal symbiosis with specific plants. Previous phylogenetic analyses suggest that around 50 species are recognized globally. Despite this previous work, no studies have analyzed the global species richness and distribution of the genus using data derived from fungal community sequencing datasets or barcoding initiatives. To assess the global diversity and species richness of Armillaria, we mined publicly available sequencing …


A Global Database Of Soil Nematode Abundance And Functional Group Composition, Johan Van Den Hoogen, Stefan Geisen, Thomas W. Crowther, Peter Mullin, Many Co-Authors Jan 2020

A Global Database Of Soil Nematode Abundance And Functional Group Composition, Johan Van Den Hoogen, Stefan Geisen, Thomas W. Crowther, Peter Mullin, Many Co-Authors

Department of Plant Pathology: Faculty Publications

As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into …


A Global Database Of Soil Nematode Abundance And Functional Group Composition, Johan Hoogen, Peter Mullen, 72 Other Scholars Jan 2014

A Global Database Of Soil Nematode Abundance And Functional Group Composition, Johan Hoogen, Peter Mullen, 72 Other Scholars

Department of Plant Pathology: Faculty Publications

As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into …


Reflections On Plant And Soil Nematode Ecology: Past, Present And Future, Howard Ferris, Bryan S. Griffiths, Dorota L. Porazinska, Thomas O. Powers, Koon-Hui Wang, Mario Tenuta Jan 2012

Reflections On Plant And Soil Nematode Ecology: Past, Present And Future, Howard Ferris, Bryan S. Griffiths, Dorota L. Porazinska, Thomas O. Powers, Koon-Hui Wang, Mario Tenuta

Department of Plant Pathology: Faculty Publications

The purpose of this review is to highlight key developments in nematode ecology from its beginnings to where it stands today as a discipline within nematology. Emerging areas of research appear to be driven by crop production constraints, environmental health concerns, and advances in technology. In contrast to past ecological studies which mainly focused on management of plant-parasitic nematodes, current studies reflect differential sensitivity of nematode faunae. These differences, identified in both aquatic and terrestrial environments include response to stressors, environmental conditions, and management practices. Methodological advances will continue to influence the role nematodes have in addressing the nature of …


Characterization Of Three-Dimensional Spatial Aggregation And Association Patterns Of Brown Rot Symptoms Within Intensively Mapped Sour Cherry Trees, Sydney E. Everhart, Ashley Askew, Lynne Seymour, Imre J. Holb, Harald Scherm Jan 2011

Characterization Of Three-Dimensional Spatial Aggregation And Association Patterns Of Brown Rot Symptoms Within Intensively Mapped Sour Cherry Trees, Sydney E. Everhart, Ashley Askew, Lynne Seymour, Imre J. Holb, Harald Scherm

Department of Plant Pathology: Faculty Publications

Characterization of spatial patterns of plant disease can provide insights into important epidemiological processes such as sources of inoculum, mechanisms of dissemination, and reproductive strategies of the pathogen population. While two-dimensional patterns of disease (among plants within fields) have been studied extensively, there is limited information on three-dimensional patterns within individual plant canopies. Reported here are the detailed mapping of different symptom types of brown rot (caused by Monilinia laxa) in individual sour cherry tree (Prunus cerasus) canopies, and the application of spatial statistics to the resulting data points to de-termine patterns of symptom aggregation and association. …


A Dgge-Cloning Method To Characterize Arbuscular Mycorrhizal Community Structure In Soil, Zhanbei Liang, Rhae A. Drijber, Donald J. Lee, Ismail M. Dwiekat, Steven D. Harris, David A. Wedin Jan 2008

A Dgge-Cloning Method To Characterize Arbuscular Mycorrhizal Community Structure In Soil, Zhanbei Liang, Rhae A. Drijber, Donald J. Lee, Ismail M. Dwiekat, Steven D. Harris, David A. Wedin

Department of Plant Pathology: Faculty Publications

Although arbuscular mycorrhizal fungi (AMF) are crucial for ecosystem functioning, characterizing AMF community structure in soil is challenging. In this study, nested polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) were combined with cloning of fungal 18S ribosomal gene fragments for the rapid comparison of AMF community structure in soil. Reference AMF isolates, representing four major genera of AMF, were used to develop the method. Sequential amplification of 18S rDNA fragments by nested PCR using primer pairs AM1-NS31 and Glo1-NS31GC followed by DGGE analysis yielded a high-resolution band profile. In parallel, 18S rDNA fragment clone libraries were constructed …


Fungal Biology And Agriculture: Revisiting The Field, O. Yarden, D. J. Ebbole, S. Freeman, R. J. Rodriguez, M. B. Dickman Jan 2003

Fungal Biology And Agriculture: Revisiting The Field, O. Yarden, D. J. Ebbole, S. Freeman, R. J. Rodriguez, M. B. Dickman

Department of Plant Pathology: Faculty Publications

Plant pathology has made significant progress over the years, a process that involved overcoming a variety of conceptual and technological hurdles. Descriptive mycology and the advent of chemical plant-disease management have been followed by biochemical and physiological studies of fungi and their hosts. The later establishment of biochemical genetics along with the introduction of DNA-mediated transformation have set the stage for dissection of gene function and advances in our understanding of fungal cell biology and plant–fungus interactions. Currently, with the advent of high-throughput technologies, we have the capacity to acquire vast data sets that have direct relevance to the numerous …


The Role Of Chitinase Production By Stenotrophomonas Maltophilia Strain C3 In Biological Control Of Bipolaris Sorokiniana, Zhongge Zhang, Gary Y. Yuen Jan 2000

The Role Of Chitinase Production By Stenotrophomonas Maltophilia Strain C3 In Biological Control Of Bipolaris Sorokiniana, Zhongge Zhang, Gary Y. Yuen

Department of Plant Pathology: Faculty Publications

The role of chitinase production by Stenotrophomonas maltophilia strain C3 in biological control of leaf spot on tall fescue (Festuca arundinacea), caused by Bipolaris sorokiniana, was investigated in vitro and in vivo. The filtrate of a broth culture of C3, with chitin as the carbon source, was separated into fractions. A high molecular-weight fraction (>8 kDa) was chitinolytic and more inhibitory than a low-molecularweight, nonchitinolytic fraction to conidial germination and hyphal growth by B. sorokiniana and to leaf spot development. A protein fraction derived by ammonium sulfate precipitation and a chitinase fraction purified by chitin affinity …


The Plant Pathogenic Corynebacteria, Anne K. Vidaver Jan 1982

The Plant Pathogenic Corynebacteria, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

The plant pathogenic corynebacteria are a fascinating group of bacteria that produce effects as diverse as any in the microbial world, ranging from wilts to abnormal growths. Several new pathogens have been discovered since this group was reviewed by Jensen (75), Starr (157), and Lelliott (96). Most subsequent reviews have dealt with taxonomy. The areas covered in this review necessarily reflect my biases and limitations. However, this review attempts to be comprehensive in some areas, and it calls attention to other areas that would benefit from more detailed investigation.


Comparative Water Relations And Photosynthesis Of Mycorrhizal And Non-Mycorrhizal Bouteloua Gracilis H.B.K. Lag Ex Steud., Michael F. Allen, William K. Smith, Thomas S. Moore Jr., Martha Christensen Jan 1981

Comparative Water Relations And Photosynthesis Of Mycorrhizal And Non-Mycorrhizal Bouteloua Gracilis H.B.K. Lag Ex Steud., Michael F. Allen, William K. Smith, Thomas S. Moore Jr., Martha Christensen

Department of Plant Pathology: Faculty Publications

The rangeland grass, Bouteloua gracilis was inoculated with its mycorrhizal symbiont, Glomus fasciculatus, to determine the influence of vesicular-arhuscular mycorrhizae on water status, stomatal behaviour and photosynthesis as well as gross plant morphology, biomass and phosphorus content. Mycorrhizal infection increased transpiration rates by over 100% with 50 to 70% lower leaf resistances to water vapour diffusion. Leaf xylem pressure was not different between mycorrhizal and non-mycorrhizal plants indicating that whole-plant resistance to water transport was reduced by more than 50%. Photosynthetic rates under saturating light conditions increased 68% with infection as a consequence of a 33% reduction in stomatal …


Bacteriocin-Like Substances Produced By Rhizobium Japonicum And Other Slow-Growing Rhizobia, D. C. Gross, A. K. Vidaver Dec 1978

Bacteriocin-Like Substances Produced By Rhizobium Japonicum And Other Slow-Growing Rhizobia, D. C. Gross, A. K. Vidaver

Department of Plant Pathology: Faculty Publications

Bacteriocin-like substances were commonly produced by slow-growing Rhizobium japonicum and cowpea rhizobia on an L-arabinose medium. Antagonism between strains of R. japonicum was not detected in vitro; however, such strains were often sensitive to some bacteriocins produced by cowpea rhizobia. Inhibitory zones (2 to 8 mm from colony margins), produced by 58 of 66 R. japonicum test strains, were reproducibly detected with Corynebacterium nebraskense as an indicator. Quantitative production was not related to symbiotic properties of effective strains, since nine noninfective strains and one ineffective strain produced bacteriocin. Eight R. japonicum strains that did not produce bacteriocin nevertheless formed effective …


Prospects For Control Of Phytopathogenic Bacteria By Bacteriophages And Bacteriocins, Anne K. Vidaver Jan 1976

Prospects For Control Of Phytopathogenic Bacteria By Bacteriophages And Bacteriocins, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

The last review on bacteriophages and bacteriocins of phytopathogenic bacteria was that of Okabe & Goto (98). All but one (21) of the subsequent reviews (II, 12, 60, 94, 104) have dealt primarily with viruses and bacteriocins of bacteria other than phytopathogens. The most recent microbiological compendia that in­ clude bacteriophages and bacteriocins are of limited value for phytobacteriolo­ gists because the authors generally overlook or ignore such agents (29, 47, 77, 119). However, Adam's classic .book (4), the review by Bradley (II), and the bibliography of Raettig (102) are still of value to phytobacteriologists as are reviews dealing principally …