@article {KNZ001266, title = {Relatedness of Macrophomina phaseolina isolates from tallgrass prairie, maize, soybean, and sorghum}, journal = {Molecular Ecology}, volume = {19}, year = {2010}, pages = {79 -91}, abstract = {

Agricultural and wild ecosystems may interact through shared pathogens such as Macrophomina phaseolina, a generalist clonal fungus with more than 284 plant hosts that is likely to become more important under climate change scenarios of increased heat and drought stress. To evaluate the degree of subdivision in populations of M. phaseolina in Kansas agriculture and wildlands, we compared 143 isolates from maize fields adjacent to tallgrass prairie, nearby sorghum fields, widely dispersed soybean fields and isolates from eight plant species in tallgrass prairie. Isolate growth phenotypes were evaluated on a medium containing chlorate. Genetic characteristics were analysed based on amplified fragment length polymorphisms and the sequence of the rDNA-internal transcribed spacer (ITS) region. The average genetic similarity was 58\% among isolates in the tallgrass prairie, 71\% in the maize fields, 75\% in the sorghum fields and 80\% in the dispersed soybean fields. The isolates were divided into four clusters: one containing most of the isolates from maize and soybean, two others containing isolates from wild plants and sorghum, and a fourth containing a single isolate recovered from Solidago canadensis in the tallgrass prairie. Most of the sorghum isolates had the dense phenotype on media containing chlorate, while those from other hosts had either feathery or restricted phenotypes. These results suggest that the tallgrass prairie supports a more diverse population of M. phaseolina per area than do any of the crop species. Subpopulations show incomplete specialization by host. These results also suggest that inoculum produced in agriculture may influence tallgrass prairie communities, and conversely that different pathogen subpopulations in tallgrass prairie can interact there to generate \‘hybrids\’ with novel genetic profiles and pathogenic capabilities.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-294X.2009.04433.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-294X.2009.04433.x}, author = {Saleh, A.A. and Ahmed, H.U. and Todd, T.C. and Travers, S.E. and Zeller, K.A. and Leslie, J.F. and Garrett, K.A.} } @article {KNZ00955, title = {Gibberella konza (Fusarium konzum) sp nov from prairie grasses, a new species in the Gibberella fujikuroi species complex}, journal = {Mycologia}, volume = {95}, year = {2004}, pages = {943 -954}, abstract = {The Gibberella fujikuroi species complex (Fusarium section Liseola and allied taxa) is composed of an increasingly large number of morphological, biological and phylogenetic species. Most of the known species in this group have been isolated from agricultural ecosystems or have been described from a small number of isolates. We sampled Fusarium communities from native prairie grasses in Kansas and recovered a large number of isolates that superficially resemble F. anthophilum. We used a combination of morphological, biological and molecular characters to describe a new species, Gibberella konza (Gibberella fujikuroi mating population I [MP-I]), from native prairie grasses in Kansas. Although female fertility for field isolates of this species appears to be low, G. konza is heterothallic, and we developed reliably female fertile mating population tester strains for this species. The F. konzum anamorph is differentiated from F. anthophilum and from other Fusarium species in section Liseola by mating compatibility, morphology, AFLP fingerprint profile and differences in β-tubulin DNA sequence.}, keywords = {LTER-KNZ, AFLP, biological species, DNA sequence, Fusarium anthophilum, mating population, β-tubulin}, url = {http://www.mycologia.org/content/95/5/943.short}, author = {Zeller, K.A. and Summerell, B.A. and Bullock, S. and Leslie, J.F.} } @article {KNZ00954, title = {Interfertility of two mating populations in the Gibberella fujikuroi species complex}, journal = {European Journal of Plant Pathology}, volume = {110}, year = {2004}, pages = {611 -618}, abstract = {Gibberella fujikuroi and Gibberella intermedia (mating populations {\textquoteleft}C{\textquoteright} and {\textquoteleft}D{\textquoteright} of the G. fujikuroi species complex) can be distinguished by differences in the spectrum of mycotoxins produced, the lack of sexual cross-fertility and diagnostic differences in their DNA sequences. Some isolates from these two biological species, however, can interbreed and complete meiosis to produce viable progeny. Analysis of marker segregation amongst such hybrid progeny can be used to estimate the degree of genomic rearrangement and genetic incompatibility that has accumulated since these sibling species diverged. Recombinant progeny were isolated from crosses of the standard tester strains for these two species and from crosses between these standard testers and a field isolate (KSU X-10626) that was cross-fertile with tester strains of both species. Progeny in all of the crosses segregated for amplified fragment length polymorphisms (AFLPs). Segregation of AFLP loci deviated from 1:1 for two thirds of the loci amongst the progeny of the cross between the {\textquoteleft}C{\textquoteright} and {\textquoteleft}D{\textquoteright} mating population tester strains, but <20\% of the polymorphic loci in the cross of either tester with KSU X-10626 showed such distortion. It was concluded that G. intermedia and G. fujikuroi are sufficiently interfertile to belong to the same biological species, but that changing the nomenclature to reflect this interfertility requires more evidence for the natural occurrence of a continuum in fertility than is presently available.}, keywords = {LTER-KNZ, AFLP, biological species, fumonisin, Fusarium fujikuroi, Fusarium proliferatum, Gibberella intermedia, interspecific hybrids, Konza Prairie, mating type, sexual crosses}, doi = {10.1007/978-1-4020-2285-2_15}, author = {Leslie, J.F. and Zeller, K.A. and Wohler, M. and Summerell, B.A.} } @article {KNZ00953, title = {Species diversity of and toxin production by Gibberella fujikuroi species complex strains isolated from native prairie grasses in Kansas}, journal = {Applied and Environmental Microbiology}, volume = {70}, year = {2004}, pages = {2254 -2262}, abstract = {Fusarium species from agricultural crops have been well studied with respect to toxin production and genetic diversity, while similar studies of communities from nonagricultural plants are much more limited. We examined 72 Fusarium isolates from a native North American tallgrass prairie and found that Gibberella intermedia (Fusarium proliferatum), Gibberella moniliformis (Fusarium verticillioides), and Gibberella konza (Fusarium konzum) dominated. Gibberella thapsina (Fusarium thapsinum) and Gibberella subglutinans (Fusarium subglutinans) also were recovered, as were seven isolates that could not be assigned to any previously described species on the basis of either morphological or molecular characters. In general, isolates from the prairie grasses produced the same toxins in quantities similar to those produced by isolates of the same species recovered from agricultural hosts. The G. konza isolates produce little or no fumonisins (up to 120 μg/g by one strain), and variable but generally low to moderate amounts of beauvericin (4 to 320 μg/g) and fusaproliferin (50 to 540 μg/g). Toxicity to Artemia salina larvae within most species was correlated with the concentration of either beauvericin or fusaproliferin produced. Organic isolates from some cultures of G. moniliformis were highly toxic towards A. salina even though they produced little, if any, beauvericin or fusaproliferin. Thus, additional potentially toxigenic compounds may be synthesized by G. moniliformis strains isolated from prairie grasses. The Fusarium community from these grasses appears to contain some species not found in surrounding agricultural communities, including some that probably are undescribed, and could be capable of serving as a reservoir for strains of potential agricultural importance.}, keywords = {LTER-KNZ}, doi = {10.1128/AEM.70.4.2254-2262.2004}, author = {Leslie, J.F. and Zeller, K.A. and Logrieco, A. and Mule, G. and Moretti, A. and Ritieni, A.} } @article {KNZ00322, title = {Root architecture of warm and cool-season grasses: relationship to mycorrhizal dependence}, journal = {Canadian Journal of Botany}, volume = {69}, year = {1991}, pages = {112 -118}, keywords = {LTER-KNZ}, doi = {10.1139/b91-016}, author = {Hetrick, B.A.D. and G.T. Wilson and Leslie, J.F.} } @article {KNZ00181, title = {Physical and topological assessment of vesicular-arbuscular mycorrhizal fungus on root architecture of big bluestem}, journal = {New Phytologist}, volume = {110}, year = {1988}, pages = {85 -96}, abstract = {

The influence of vesicular-arbuscular (VA) mycorrhizal fungus, phosphorus (P) fertilization, and soil microorganisms on growth and root architecture of big bluestem (Andropogon gerardii Vitman) was investigated. In pasteurized soil, mycorrhizal inoculation significantly improved plant growth and increased root length and the number and the diameter of the primary, secondary and tertiary roots. These differences between mycorrhizal and non-mycorrhizal plants diminished with added P. In pasteurized soil amended with non-sterile soil sievate, differences between mycorrhizal and non-mycorrhizal plants were still obvious, but in may treatments these plants grew more poorly (had less dry weight, root length, number or diameter) than their counterparts in unamended pasteurized soil. Growth in non-sterile soil was also suppressed, and mycorrhizal responses were not detected since all of the plants in non-sterile soil became mycorrhizal whether or not they were inoculated. Two analyses of calculated parameters which describe root- system architecture were conducted. The first, specific root length (SRL), revealed that mycorrhizal symbiosis dramatically alters root morphology in soils of low fertility. These changes were similar to the changes evoked by added P. The second, path length (Pe) revealed that mycorrhizal fungi (and to some degree other soil microbes) significantly alter root architecture by reducing the relative amount of root branching. Apparently, mycorrhizal plants develop a more elongate, exploratory growth pattern which permits the fungal hyphae to extract nutrients from a larger volume of soil. In contract roots of non-mycorrhizal plants maintain a more highly branched pattern of root growth, and the roots themselves play a more critical role in the direct extraction of nutrients from the soil. These differences in root topology were not directly associated with the concentration of exogenous P, but instead appeared to be controlled by the mycorrhizal fungi themselves. Thus, while internal P content of plants mediates the establishment of the mycorrhizal symbiosis, the fungi can alter the root architecture of the plant to a form which best accommodates the symbiosis under the prevailing fertility and rhizosphere conditions in the soil. By altering root-system architecture in this manner, the mycorrhizal fungi can control, at least to some degree, the dependence of the host on the symbiosis. Thus, the topology of the root system is contingent upon the microflora in the rhizosphere. The topological analysis revealed differences in root architecture not detected by any of the other measures of root morphology. These differences suggest that mycorrhizal fungi affect root architecture and plant growth in ways not directly associated with phosphorus uptake. Key words: path length, phosphorus, root morphology, specific root length

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1469-8137.1988.tb00240.x}, author = {Hetrick, B.A.D. and Leslie, J.F. and G.T. Wilson and Kitt, D.G.} }