Phylogeography of the Solanaceae-infecting Basidiomycota fungus Rhizoctonia solani AG-3 based on sequence analysis of two nuclear DNA loci

<p>Abstract</p> <p>Background</p> <p>The soil fungus <it>Rhizoctonia solani </it>anastomosis group 3 (AG-3) is an important pathogen of cultivated plants in the family Solanaceae. Isolates of <it>R. solani </it>AG-3 are taxonomically related based on the composition of cellular fatty acids, phylogenetic analysis of nuclear ribosomal DNA (rDNA) and beta-tubulin gene sequences, and somatic hyphal interactions. Despite the close genetic relationship among isolates of <it>R. solani </it>AG-3, field populations from potato and tobacco exhibit comparative differences in their disease biology, dispersal ecology, host specialization, genetic diversity and population structure. However, little information is available on how field populations of <it>R. solani </it>AG-3 on potato and tobacco are shaped by population genetic processes. In this study, two field populations of <it>R. solani </it>AG-3 from potato in North Carolina (NC) and the Northern USA; and two field populations from tobacco in NC and Southern Brazil were examined using sequence analysis of two cloned regions of nuclear DNA (pP42F and pP89).</p> <p>Results</p> <p>Populations of <it>R. solani </it>AG-3 from potato were genetically diverse with a high frequency of heterozygosity, while limited or no genetic diversity was observed within the highly homozygous tobacco populations from NC and Brazil. Except for one isolate (TBR24), all NC and Brazilian isolates from tobacco shared the same alleles. No alleles were shared between potato and tobacco populations of <it>R. solani </it>AG-3, indicating no gene flow between them. To infer historical events that influenced current geographical patterns observed for populations of <it>R. solani </it>AG-3 from potato, we performed an analysis of molecular variance (AMOVA) and a nested clade analysis (NCA). Population differentiation was detected for locus pP89 (Φ_{<it>ST </it>}= 0.257, significant at P < 0.05) but not for locus pP42F (Φ_{<it>ST </it>}= 0.034, not significant). Results based on NCA of the pP89 locus suggest that historical restricted gene flow is a plausible explanation for the geographical association of clades. Coalescent-based simulations of genealogical relationships between populations of <it>R. solani </it>AG-3 from potato and tobacco were used to estimate the amount and directionality of historical migration patterns in time, and the ages of mutations of populations. Low rates of historical movement of genes were observed between the potato and tobacco populations of <it>R. solani </it>AG-3.</p> <p>Conclusion</p> <p>The two sisters populations of the basidiomycete fungus <it>R. solani </it>AG-3 from potato and tobacco represent two genetically distinct and historically divergent lineages that have probably evolved within the range of their particular related Solanaceae hosts as sympatric species.</p

Analysis of mycobiomes to uncover biodiversity: a case study between soil fungi and orchid species in Sweden

Abstracts from the April 12-14, 2019 MASC Conferenc

Editorial: The Use and Understanding of Style Differences to Enhance Learning

Comparison of Molecular Function annotations of R. solani genes between the induced (log2FPKM > 0) and repressed (log2FPKM < 0) genes when challenged with S4 Serratia proteamaculans. (FPMK = fragments per kilobase of exon per million fragments mapped

Draft genome sequence of the plant-pathogenic soil fungus Rhizoctonia solani anastomosis group 3 strain Rhs1AP

The soil fungus Rhizoctonia solani is a pathogen of agricultural crops. Here, we report on the 51,705,945 bp draft consensus genome sequence of R. solani strain Rhs1AP. A comprehensive understanding of the heterokaryotic genome complexity and organization of R. solani may provide insight into the plant disease ecology and adaptive behavior of the fungus

"Jumping Jack": Genomic Microsatellites Underscore the Distinctiveness of Closely Related Pseudoperonospora cubensis and Pseudoperonospora humuli and Provide New Insights Into Their Evolutionary Past

Downy mildews caused by obligate biotrophic oomycetes result in severe crop losses worldwide. Among these pathogens, Pseudoperonospora cubensis and P. humuli, two closely related oomycetes, adversely affect cucurbits and hop, respectively. Discordant hypotheses concerning their taxonomic relationships have been proposed based on host-pathogen interactions and specificity evidence and gene sequences of a few individuals, but population genetics evidence supporting these scenarios is missing. Furthermore, nuclear and mitochondrial regions of both pathogens have been analyzed using microsatellites and phylogenetically informative molecular markers, but extensive comparative population genetics research has not been done. Here, we genotyped 138 current and historical herbarium specimens of those two taxa using microsatellites (SSRs). Our goals were to assess genetic diversity and spatial distribution, to infer the evolutionary history of P. cubensis and P. humuli, and to visualize genome-scale organizational relationship between both pathogens. High genetic diversity, modest gene flow, and presence of population structure, particularly in P. cubensis, were observed. When tested for cross-amplification, 20 out of 27 P. cubensis-derived gSSRs cross-amplified DNA of P. humuli individuals, but few amplified DNA of downy mildew pathogens from related genera. Collectively, our analyses provided a definite argument for the hypothesis that both pathogens are distinct species, and suggested further speciation in the P. cubensis complex

A Model for Creating Connections and Building Collections-Based Curricula for Pre-College Educators

Science is increasingly emphasized in high school classrooms and compliments current Science, Technology, Engineering, and Math (STEM) and Science, Technology, Engineering, the Arts, and Math (STEAM) educational initiatives. Successful educational programs and activities must now be aligned to state and national science standards, including Next Generation Science Standards (NGSS). The NGSS contain three dimensions: practices, crosscutting concepts, and disciplinary core ideas. Natural history collections and collections data naturally complement these three dimensions. However, many educators are unfamiliar with collections and unaware of the resources available through data aggregators such as the Integrated Digitized Biocollections (iDigBio). How can we make educators aware of these resources and empower them to implement these resources as educational tools in their classrooms? At the 2016 Incorporating K-12 Outreach into Digitized Collections Programs workshop and 2017 National Science Teacher Association meeting, iDigBio staff discussed these questions with educational experts from the United States. The consensus was that activities needed to align with appropriate teaching standards, as a bare minimum, and that building relationships with the target audience was crucial to introducing new educational materials into the classroom. Once educators become comfortable and familiar with new resources via hands-on training, they would be more likely to implement them into their respective classrooms. In July 2018, a 3-day workshop “Drawers, Jars, and Databases: Teaching the Hidden Science of Natural History Museums" was held at the North Carolina Museum of Natural Sciences (NCMNS) in Raleigh. The workshop was designed to serve as a pilot program to determine if training and building of relationships with local educators will increase use of digitized collections data in the classroom. Partners hosting this workshop included staff from iDigBio, the MicroFungi Thematic Collections Network, and NCMNS. This presentation will expand upon methods used to address and achieve workshop goals of increasing the knowledge of natural history collections and collections data, as well as, increasing the competency for implementing collections-based activities utilizing data aggregators in the classroom

A Model for Creating Connections and Building Collections-Based Curricula for Pre-College Educators

Science is increasingly emphasized in high school classrooms and compliments current Science, Technology, Engineering, and Math (STEM) and Science, Technology, Engineering, the Arts, and Math (STEAM) educational initiatives. Successful educational programs and activities must now be aligned to state and national science standards, including Next Generation Science Standards (NGSS). The NGSS contain three dimensions: practices, crosscutting concepts, and disciplinary core ideas. Natural history collections and collections data naturally complement these three dimensions. However, many educators are unfamiliar with collections and unaware of the resources available through data aggregators such as the Integrated Digitized Biocollections (iDigBio). How can we make educators aware of these resources and empower them to implement these resources as educational tools in their classrooms? At the 2016 Incorporating K-12 Outreach into Digitized Collections Programs workshop and 2017 National Science Teacher Association meeting, iDigBio staff discussed these questions with educational experts from the United States. The consensus was that activities needed to align with appropriate teaching standards, as a bare minimum, and that building relationships with the target audience was crucial to introducing new educational materials into the classroom. Once educators become comfortable and familiar with new resources via hands-on training, they would be more likely to implement them into their respective classrooms. In July 2018, a 3-day workshop “Drawers, Jars, and Databases: Teaching the Hidden Science of Natural History Museums" was held at the North Carolina Museum of Natural Sciences (NCMNS) in Raleigh. The workshop was designed to serve as a pilot program to determine if training and building of relationships with local educators will increase use of digitized collections data in the classroom. Partners hosting this workshop included staff from iDigBio, the MicroFungi Thematic Collections Network, and NCMNS. This presentation will expand upon methods used to address and achieve workshop goals of increasing the knowledge of natural history collections and collections data, as well as, increasing the competency for implementing collections-based activities utilizing data aggregators in the classroom

Association of Ceratobasidium theobromae and Lasiodiplodia species with symptom variation in vascular streak disease of cacao

Abstracts from the April 12-14, 2019 MASC Conferenc

Using digital resources to enhance georeferencing of herbarium collections

Abstracts from the April 12-14, 2019 MASC Conferenc

Geography and hosts of the wood decay fungi Fomes fasciatus and Fomes fomentarius in the United States

Comprehensive United States county distribution maps of Fomes fasciatus and F. fomentarius were developed based on peer-reviewed publications, records from mycological herbaria and collections made for this study. The geographic distribution was expanded for both species to include a total of seven counties in five states not included in previous publications and records. North Carolina and Tennessee were the only states where both species occurred, but their distributions did not overlap when resolved to the county level. Both fungi occurred on a diverse range of hardwood tree hosts, and in this study, 11 and 17 new hosts associations were identified for F. fasciatus and F. fomentarius, respectively. The extension of host distributions beyond the known range for each fungus suggests that other delimiting factors may contribute to the distribution of F. fasciatus and F. fomentarius