1
|
Lekberg Y, Jansa J, McLeod M, DuPre ME, Holben WE, Johnson D, Koide RT, Shaw A, Zabinski C, Aldrich-Wolfe L. Carbon and phosphorus exchange rates in arbuscular mycorrhizas depend on environmental context and differ among co-occurring plants. New Phytol 2024; 242:1576-1588. [PMID: 38173184 DOI: 10.1111/nph.19501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/08/2023] [Indexed: 01/05/2024]
Abstract
Phosphorus (P) for carbon (C) exchange is the pivotal function of arbuscular mycorrhiza (AM), but how this exchange varies with soil P availability and among co-occurring plants in complex communities is still largely unknown. We collected intact plant communities in two regions differing c. 10-fold in labile inorganic P. After a 2-month glasshouse incubation, we measured 32P transfer from AM fungi (AMF) to shoots and 13C transfer from shoots to AMF using an AMF-specific fatty acid. AMF communities were assessed using molecular methods. AMF delivered a larger proportion of total shoot P in communities from high-P soils despite similar 13C allocation to AMF in roots and soil. Within communities, 13C concentration in AMF was consistently higher in grass than in blanketflower (Gaillardia aristata Pursh) roots, that is P appeared more costly for grasses. This coincided with differences in AMF taxa composition and a trend of more vesicles (storage structures) but fewer arbuscules (exchange structures) in grass roots. Additionally, 32P-for-13C exchange ratios increased with soil P for blanketflower but not grasses. Contrary to predictions, AMF transferred proportionally more P to plants in communities from high-P soils. However, the 32P-for-13C exchange differed among co-occurring plants, suggesting differential regulation of the AM symbiosis.
Collapse
Affiliation(s)
- Ylva Lekberg
- MPG Ranch, Missoula, MT, 59801, USA
- Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, MT, 59812, USA
| | - Jan Jansa
- Institute of Microbiology of the Czech Academy of Sciences, Prague, 14220, Czech Republic
| | | | | | - William E Holben
- Cellular, Molecular and Microbial Biology, University of Montana, Missoula, MT, 59812, USA
| | - David Johnson
- Department of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - Roger T Koide
- Department of Biology, Brigham Young University, Provo, UT, 84602, USA
| | - Alanna Shaw
- Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, MT, 59812, USA
| | - Catherine Zabinski
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, 59717, USA
| | - Laura Aldrich-Wolfe
- Department of Biological Sciences, North Dakota State University, Fargo, ND, 58108, USA
| |
Collapse
|
2
|
Escudero-Leyva E, Del Milagro Granados-Montero M, Orozco-Ortiz C, Araya-Valverde E, Alvarado-Picado E, Chaves-Fallas JM, Aldrich-Wolfe L, Chaverri P. The endophytobiome of wild Rubiaceae as a source of antagonistic fungi against the American Leaf Spot of coffee (Mycena citricolor). J Appl Microbiol 2023; 134:7146202. [PMID: 37113015 DOI: 10.1093/jambio/lxad090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/26/2023] [Indexed: 04/29/2023]
Abstract
AIMS The American leaf spot, caused by Mycena citricolor, is an important disease of coffee (Coffea arabica), mostly in Central America. Currently, there are limited pathogen control alternatives that are environmentally friendly and economically accessible. The use of fungi isolated from the plant endomycobiota in their native habitats is on the rise because studies show their great potential for biological control. To begin to generate a green alternative to control M. citricolor, the objectives of the present study were to (i) collect, identify, screen (in vitro and in planta), and select endophytic fungi from wild Rubiaceae collected in old-growth forests of Costa Rica; (ii) confirm endophytic colonization in coffee plantlets; (iii) evaluate the effects of the endophytes on plantlet development; and (iv) corroborate the antagonistic ability in planta. METHODS AND RESULTS Through in vitro and in planta antagonism assays, we found that out of the selected isolates (i.e., Daldinia eschscholzii GU11N, Nectria pseudotrichia GUHN1, Purpureocillium aff. lilacinum CT24, Sarocladium aff. kiliense CT25, Trichoderma rifaii CT5, T. aff. crassum G1C, T. aff. atroviride G7T, T. aff. strigosellum GU12, and Xylaria multiplex GU14T), Trichoderma spp. produced the highest growth inhibition percentages in vitro. Trichoderma isolates CT5 and G1C were then tested in planta using Coffea arabica cv. caturra plantlets. Endophytic colonization was verified, followed by in planta growth promotion and antagonism assays. CONCLUSIONS Results show that Trichoderma isolates CT5 and G1C have potential for plant growth promotion and antagonism against Mycena citricolor, reducing incidence and severity, and preventing plant mortality.
Collapse
Affiliation(s)
- Efraín Escudero-Leyva
- Centro de Investigaciones en Productos Naturales (CIPRONA) and Escuela de Biología, Universidad de Costa Rica, San Pedro, San José, Costa Rica
- Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, Pavas, San José, Costa Rica
| | - María Del Milagro Granados-Montero
- Escuela de Agronomía, Estación Experimental Fabio Baudrit and Centro de Investigaciones en Estructuras Microscópicas, Universidad de Costa Rica, San Pedro, San José, Costa Rica
| | - Cristofer Orozco-Ortiz
- Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, Pavas, San José, Costa Rica
| | - Emmanuel Araya-Valverde
- Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, Pavas, San José, Costa Rica
| | - Eduardo Alvarado-Picado
- Centro para el Desarrollo de Alternativas Orgánicas (CeDAO), San Marcos de Tarrazú, San José, Costa Rica
| | - José Miguel Chaves-Fallas
- Centro de Investigaciones en Productos Naturales (CIPRONA) and Escuela de Biología, Universidad de Costa Rica, San Pedro, San José, Costa Rica
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Laura Aldrich-Wolfe
- Department of Biological Sciences, North Dakota State University, Fargo, North Dakota, USA
| | - Priscila Chaverri
- Centro de Investigaciones en Productos Naturales (CIPRONA) and Escuela de Biología, Universidad de Costa Rica, San Pedro, San José, Costa Rica
- Department of Natural Sciences, Bowie State University, Bowie, Maryland, USA
| |
Collapse
|
3
|
Prischmann-Voldseth DA, Özsisli T, Aldrich-Wolfe L, Anderson K, Harris MO. Microbial Inoculants Differentially Influence Plant Growth and Biomass Allocation in Wheat Attacked by Gall-Inducing Hessian Fly (Diptera: Cecidomyiidae). Environ Entomol 2020; 49:1214-1225. [PMID: 32860049 DOI: 10.1093/ee/nvaa102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Indexed: 06/11/2023]
Abstract
Beneficial root microbes may mitigate negative effects of crop pests by enhancing plant tolerance or resistance. We used a greenhouse experiment to investigate impacts of commercially available microbial root inoculants on growth and biomass allocation of wheat (Triticum aestivum L. [Cyperales: Poaceae]) and on survival and growth of the gall-inducing wheat pest Hessian fly, Mayetiola destructor (Say). A factorial design was used, with two near-isogenic wheat lines (one susceptible to Hessian fly, the other resistant), two levels of insect infestation (present, absent), and four inoculants containing: 1) Azospirillum brasilense Tarrand et al. (Rhodospirillales: Azospirillaceae), a plant growth-promoting bacterium, 2) Rhizophagus intraradices (N.C. Schenck & G.S. Sm.) (Glomerales: Glomeraceae), an arbuscular mycorrhizal fungus, 3) A. brasilense + R. intraradices, and 4) control, no inoculant. Larval feeding stunted susceptible wheat shoots and roots. Plants had heavier roots and allocated a greater proportion of biomass to roots when plants received the inoculant with R. intraradices, regardless of wheat genotype or insect infestation. Plants receiving the inoculant containing A. brasilense (alone or with R. intraradices) had comparable numbers of tillers between infested and noninsect-infested plants and, if plants were susceptible, a greater proportion of aboveground biomass was allocated to tillers. However, inoculants did not impact density or performance of Hessian fly immatures or metrics associated with adult fitness. Larvae survived and grew normally on susceptible plants and mortality was 100% on resistant plants irrespective of inoculants. This initial study suggests that by influencing plant biomass allocation, microbial inoculants may offset negative impacts of Hessian flies, with inoculant identity impacting whether tolerance is related to root or tiller growth.
Collapse
Affiliation(s)
| | - Tülin Özsisli
- Agricultural Faculty, Department of Plant Protection, Kahramanmaraş Sütcü Imam University, Avşar Campus, Kahramanmaras, Turkey
| | - Laura Aldrich-Wolfe
- Department of Biological Sciences 2715, North Dakota State University, Fargo, ND
| | - Kirk Anderson
- Department of Entomology 7650, North Dakota State University, Fargo, ND
| | - Marion O Harris
- Department of Entomology 7650, North Dakota State University, Fargo, ND
| |
Collapse
|
4
|
Aldrich-Wolfe L, Black KL, Hartmann EDL, Shivega WG, Schmaltz LC, McGlynn RD, Johnson PG, Asheim Keller RJ, Vink SN. Taxonomic shifts in arbuscular mycorrhizal fungal communities with shade and soil nitrogen across conventionally managed and organic coffee agroecosystems. Mycorrhiza 2020; 30:513-527. [PMID: 32500441 DOI: 10.1007/s00572-020-00967-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
The composition of arbuscular mycorrhizal fungal (AMF) communities should reflect not only responses to host and soil environments, but also differences in functional roles and costs vs. benefits among arbuscular mycorrhizal fungi. The coffee agroecosystem allows exploration of the effects of both light and soil fertility on AMF communities, because of the variation in shade and soil nutrients farmers generate through field management. We used high-throughput ITS2 sequencing to characterize the AMF communities of coffee roots in 25 fields in Costa Rica that ranged from organic management with high shade and no chemical fertilizers to conventionally managed fields with minimal shade and high N fertilization, and examined relationships between AMF communities and soil and shade parameters with partial correlations, NMDS, PERMANOVA, and partial least squares analysis. Gigasporaceae and Acaulosporaceae dominated coffee AMF communities in terms of relative abundance and richness, respectively. Gigasporaceae richness was greatest in conventionally managed fields, while Glomeraceae richness was greatest in organic fields. While total AMF richness and root colonization did not differ between organic and conventionally managed fields, AMF community composition did; these differences were correlated with soil nitrate and shade. OTUs differing in relative abundance between conventionally managed and organic fields segregated into four groups: Gigasporaceae associated with high light and nitrate availability, Acaulosporaceae with high light and low nitrate availability, Acaulosporaceae and a single relative of Rhizophagus fasciculatus with shade and low nitrate availability, and Claroideoglomus/Glomus with conventionally managed fields but uncorrelated with shade and soil variables. The association of closely related taxa with similar shade and light availabilities is consistent with phylogenetic trait conservatism in AM fungi.
Collapse
Affiliation(s)
- Laura Aldrich-Wolfe
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA.
| | - Katie L Black
- Biology Department, Concordia College, Moorhead, MN, USA
| | | | - W Gaya Shivega
- Biology Department, Concordia College, Moorhead, MN, USA
| | | | | | | | | | - Stefanie N Vink
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| |
Collapse
|
5
|
Bachelot B, Alonso-Rodríguez AM, Aldrich-Wolfe L, Cavaleri MA, Reed SC, Wood TE. Altered climate leads to positive density-dependent feedbacks in a tropical wet forest. Glob Chang Biol 2020; 26:3417-3428. [PMID: 32196863 DOI: 10.1111/gcb.15087] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/02/2020] [Indexed: 05/12/2023]
Abstract
Climate change is predicted to result in warmer and drier Neotropical forests relative to current conditions. Negative density-dependent feedbacks, mediated by natural enemies, are key to maintaining the high diversity of tree species found in the tropics, yet we have little understanding of how projected changes in climate are likely to affect these critical controls. Over 3 years, we evaluated the effects of a natural drought and in situ experimental warming on density-dependent feedbacks on seedling demography in a wet tropical forest in Puerto Rico. In the +4°C warming treatment, we found that seedling survival increased with increasing density of the same species (conspecific). These positive density-dependent feedbacks were not associated with a decrease in aboveground natural enemy pressure. If positive density-dependent feedbacks are not transient, the diversity of tropical wet forests, which may rely on negative density dependence to drive diversity, could decline in a future warmer, drier world.
Collapse
Affiliation(s)
| | - Aura M Alonso-Rodríguez
- USDA Forest Service International Institute of Tropical Forestry, Jardín Botánico Sur, Río Piedras, Puerto Rico
| | - Laura Aldrich-Wolfe
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA
| | - Molly A Cavaleri
- School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, USA
| | - Sasha C Reed
- Southwest Biological Science Center, US Geological Survey, Moab, UT, USA
| | - Tana E Wood
- USDA Forest Service International Institute of Tropical Forestry, Jardín Botánico Sur, Río Piedras, Puerto Rico
| |
Collapse
|
6
|
Sternhagen EC, Black KL, Hartmann EDL, Shivega WG, Johnson PG, McGlynn RD, Schmaltz LC, Asheim Keller RJ, Vink SN, Aldrich-Wolfe L. Contrasting Patterns of Functional Diversity in Coffee Root Fungal Communities Associated with Organic and Conventionally Managed Fields. Appl Environ Microbiol 2020; 86:e00052-20. [PMID: 32220838 PMCID: PMC7237791 DOI: 10.1128/aem.00052-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/16/2020] [Indexed: 11/20/2022] Open
Abstract
The structure and function of fungal communities in the coffee rhizosphere are influenced by crop environment. Because coffee can be grown along a management continuum from conventional application of pesticides and fertilizers in full sun to organic management in a shaded understory, we used coffee fields to hold host constant while comparing rhizosphere fungal communities under markedly different environmental conditions with regard to shade and inputs. We characterized the shade and soil environment in 25 fields under conventional, organic, or transitional management in two regions of Costa Rica. We amplified the internal transcribed spacer 2 (ITS2) region of fungal DNA from coffee roots in these fields and characterized the rhizosphere fungal community via high-throughput sequencing. Sequences were assigned to guilds to determine differences in functional diversity and trophic structure among coffee field environments. Organic fields had more shade, a greater richness of shade tree species, and more leaf litter and were less acidic, with lower soil nitrate availability and higher soil copper, calcium, and magnesium availability than conventionally managed fields, although differences between organic and conventionally managed fields in shade and calcium and magnesium availability depended on region. Differences in richness and community composition of rhizosphere fungi between organic and conventionally managed fields were also correlated with shade, soil acidity, and nitrate and copper availability. Trophic structure differed with coffee field management. Saprotrophs, plant pathogens, and mycoparasites were more diverse, and plant pathogens were more abundant, in organic than in conventionally managed fields, while saprotroph-plant pathogens were more abundant in conventionally managed fields. These differences reflected environmental differences and depended on region.IMPORTANCE Rhizosphere fungi play key roles in ecosystems as nutrient cyclers, pathogens, and mutualists, yet little is currently known about which environmental factors and how agricultural management may influence rhizosphere fungal communities and their functional diversity. This field study of the coffee agroecosystem suggests that organic management not only fosters a greater overall diversity of fungi, but it also maintains a greater richness of saprotrophic, plant-pathogenic, and mycoparasitic fungi that has implications for the efficiency of nutrient cycling and regulation of plant pathogen populations in agricultural systems. As well as influencing community composition and richness of rhizosphere fungi, shade management and use of fungicides and synthetic fertilizers altered the trophic structure of the coffee agroecosystem.
Collapse
Affiliation(s)
- Elizabeth C Sternhagen
- Department of Biological Sciences, North Dakota State University, Fargo, North Dakota, USA
| | - Katie L Black
- Biology Department, Concordia College, Moorhead, Minnesota, USA
| | | | - W Gaya Shivega
- Biology Department, Concordia College, Moorhead, Minnesota, USA
| | - Peter G Johnson
- Biology Department, Concordia College, Moorhead, Minnesota, USA
| | - Riley D McGlynn
- Biology Department, Concordia College, Moorhead, Minnesota, USA
| | | | | | - Stefanie N Vink
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | - Laura Aldrich-Wolfe
- Department of Biological Sciences, North Dakota State University, Fargo, North Dakota, USA
| |
Collapse
|
7
|
Bueno CG, Aldrich-Wolfe L, Chaudhary VB, Gerz M, Helgason T, Hoeksema JD, Klironomos J, Lekberg Y, Leon D, Maherali H, Öpik M, Zobel M, Moora M. Misdiagnosis and uncritical use of plant mycorrhizal data are not the only elephants in the room. New Phytol 2019; 224:1415-1418. [PMID: 31246312 DOI: 10.1111/nph.15976] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Affiliation(s)
- C Guillermo Bueno
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, 51005, Tartu, Estonia
| | - Laura Aldrich-Wolfe
- Department of Biological Sciences, North Dakota State University, PO Box 6050, Fargo, ND, 58108, USA
| | - V Bala Chaudhary
- Department of Environmental Science and Studies, DePaul University, 1110 West Belden Ave, Chicago, IL, 60614-2245, USA
| | - Maret Gerz
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, 51005, Tartu, Estonia
| | - Thorunn Helgason
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Jason D Hoeksema
- Department of Biology, University of Mississippi, PO Box 1848, University, MS, 38677, USA
| | - John Klironomos
- Department of Biology, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - Ylva Lekberg
- MPG Ranch, 1001 S. Higgins Ave, Missoula, MT, 59801, USA
- Department of Ecosystem Conservation Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Daniela Leon
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, 51005, Tartu, Estonia
| | - Hafiz Maherali
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Maarja Öpik
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, 51005, Tartu, Estonia
| | - Martin Zobel
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, 51005, Tartu, Estonia
| | - Mari Moora
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, 51005, Tartu, Estonia
| |
Collapse
|
8
|
Gaya Shivega W, Aldrich-Wolfe L. Native plants fare better against an introduced competitor with native microbes and lower nitrogen availability. AoB Plants 2017; 9:plx004. [PMID: 28122737 PMCID: PMC5402526 DOI: 10.1093/aobpla/plx004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/23/2016] [Accepted: 12/22/2016] [Indexed: 05/24/2023]
Abstract
While the soil environment is generally acknowledged as playing a role in plant competition, the relative importance of soil resources and soil microbes in determining outcomes of competition between native and exotic plants has rarely been tested. Resilience of plant communities to invasion by exotic species may depend on the extent to which native and exotic plant performance are mediated by abiotic and biotic components of the soil. We used a greenhouse experiment to compare performance of two native prairie plant species and one exotic species, when grown in intraspecific competition and when each native was grown in interspecific competition with the exotic species, in the presence and absence of a native prairie soil community, and when nitrogen availability was elevated or was maintained at native prairie levels. We found that elevated nitrogen availability was beneficial to the exotic species and had no effect on or was detrimental to the native plant species, that the native microbial community was beneficial to the native plant species and either had no effect or was detrimental to the exotic species, and that intraspecific competition was stronger than interspecific competition for the exotic plant species and vice-versa for the natives. Our results demonstrate that soil nitrogen availability and the soil microbial community can mediate the strength of competition between native and exotic plant species. We found no evidence for native microbes enhancing the performance of the exotic plant species. Instead, loss of the native soil microbial community appears to reinforce the negative effects of elevated N on native plant communities and its benefits to exotic invasive species. Resilience of plant communities to invasion by exotic plant species is facilitated by the presence of an intact native soil microbial community and weakened by anthropogenic inputs of nitrogen.
Collapse
Affiliation(s)
- W Gaya Shivega
- Department of Biology, Concordia College, Moorhead, Minnesota 56562, USA
| | | |
Collapse
|
9
|
Aldrich-Wolfe L, Travers S, Nelson BD. Genetic Variation of Sclerotinia sclerotiorum from Multiple Crops in the North Central United States. PLoS One 2015; 10:e0139188. [PMID: 26417989 PMCID: PMC4587960 DOI: 10.1371/journal.pone.0139188] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 09/10/2015] [Indexed: 11/19/2022] Open
Abstract
Sclerotinia sclerotiorum is an important pathogen of numerous crops in the North Central region of the United States. The objective of this study was to examine the genetic diversity of 145 isolates of the pathogen from multiple hosts in the region. Mycelial compatibility groups (MCG) and microsatellite haplotypes were determined and analyzed for standard estimates of population genetic diversity and the importance of host and distance for genetic variation was examined. MCG tests indicated there were 49 different MCGs in the population and 52 unique microsatellite haplotypes were identified. There was an association between MCG and haplotype such that isolates belonging to the same MCG either shared identical haplotypes or differed at no more than 2 of the 12 polymorphic loci. For the majority of isolates, there was a one-to-one correspondence between MCG and haplotype. Eleven MCGs shared haplotypes. A single haplotype was found to be prevalent throughout the region. The majority of genetic variation in the isolate collection was found within rather than among host crops, suggesting little genetic divergence of S. sclerotiorum among hosts. There was only weak evidence of isolation by distance. Pairwise population comparisons among isolates from canola, dry bean, soybean and sunflower suggested that gene flow between host-populations is more common for some crops than others. Analysis of linkage disequilibrium in the isolates from the four major crops indicated primarily clonal reproduction, but also evidence of genetic recombination for isolates from canola and sunflower. Accordingly, genetic diversity was highest for populations from canola and sunflower. Distribution of microsatellite haplotypes across the study region strongly suggest that specific haplotypes of S. sclerotiorum are often found on multiple crops, movement of individual haplotypes among crops is common and host identity is not a barrier to gene flow for S. sclerotiorum in the north central United States.
Collapse
Affiliation(s)
- Laura Aldrich-Wolfe
- Biology Department, Concordia College, Moorhead, Minnesota, United States of America
| | - Steven Travers
- Department of Biological Sciences, North Dakota State University, Fargo, North Dakota, United States of America
| | - Berlin D. Nelson
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, United States of America
| |
Collapse
|
10
|
Ross AA, Aldrich-Wolfe L, Lance S, Glenn T, Travers SE. Microsatellite markers in the western prairie fringed orchid, Platanthera praeclara (Orchidaceae). Appl Plant Sci 2013; 1:apps1200413. [PMID: 25202536 PMCID: PMC4105293 DOI: 10.3732/apps.1200413] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 09/21/2012] [Indexed: 06/03/2023]
Abstract
PREMISE OF THE STUDY Primers for 31 microsatellite-containing loci were developed for the threatened orchid Platanthera praeclara to enable characterization of the population genetics of this tallgrass prairie native. • METHODS AND RESULTS Sixteen polymorphic microsatellite loci were identified from four populations. Six of these loci were not in linkage disequilibrium. The average number of alleles per locus per population ranged from 6.4 to 8.9. • CONCLUSIONS The results indicate that six of the polymorphic loci will be useful in future studies of population structure, gene flow, and genetic diversity.
Collapse
Affiliation(s)
- Andrew A. Ross
- Department of Biological Sciences, NDSU Dept. 2715, North Dakota State University, Fargo, North Dakota 58108 USA
| | | | - Stacey Lance
- Environmental Health Science, University of Georgia, Athens, Georgia 30602 USA
| | - Travis Glenn
- Environmental Health Science, University of Georgia, Athens, Georgia 30602 USA
| | - Steven E. Travers
- Department of Biological Sciences, NDSU Dept. 2715, North Dakota State University, Fargo, North Dakota 58108 USA
| |
Collapse
|
11
|
Walker JF, Aldrich-Wolfe L, Riffel A, Barbare H, Simpson NB, Trowbridge J, Jumpponen A. Diverse Helotiales associated with the roots of three species of Arctic Ericaceae provide no evidence for host specificity. New Phytol 2011; 191:515-527. [PMID: 21463329 DOI: 10.1111/j.1469-8137.2011.03703.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Ericoid mycorrhizal fungi differ in their abilities to use nitrogen sources and may be integral to maintaining fungal and plant diversity in ecosystems in which Ericaceae occur. In this study, we tested whether the fungal communities differ among three species of co-occurring Ericaceae. Fungi colonizing Cassiope tetragona, Empetrum nigrum and Vaccinium vitis-idaea roots in the Arctic tundra were characterized via culture-dependent and culture-independent techniques. The cultured fungi were tested for their ability to colonize Vaccinium uliginosum in laboratory-based assays. The pure-cultured Helotiales were grouped into eight clades and dominated by the Phialocephala-Acephala complex. Representatives of these clades, plus an unknown basidiomycete with affinity to the genus Irpex (Polyporales), colonized V. uliginosum intracellularly. The Helotiales detected by direct PCR, cloning and sequencing were assigned to 14 clades and dominated by members of the Rhizoscyphus ericae complex. Ordination analyses indicated that culture-dependent and culture-independent assays provided distinct views of root fungal communities, but no evidence for host specificity. These data suggest that ericaceous roots host diverse fungal communities dominated by the Helotiales. However, these fungal communities are unlikely to be controlled by fungal host preferences. The mechanisms maintaining high diversity in root-symbiotic communities remain to be elucidated.
Collapse
Affiliation(s)
- John F Walker
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | - Amanda Riffel
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Holly Barbare
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | - Justin Trowbridge
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ari Jumpponen
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| |
Collapse
|
12
|
Abstract
The extent to which interspecific plants share mycorrhizal fungal communities depends on the specificity of the symbiosis. For tropical forest tree seedlings, colonization by mycorrhizal fungi associated with established vegetation could have important consequences for survival and growth. I used a novel molecular technique to assess the potential for sharing of mycorrhizas in forest and pasture in southern Costa Rica, by identifying arbuscular mycorrhizal (AM) fungi in roots of the forest canopy tree species Terminalia amazonia, pasture grasses Urochloa ruziziensis and U. decumbens, and seedlings of T. amazonia planted into experimental reforestation plots. I tested the hypotheses that experimental seedlings were colonized either by the AM fungal community of the forest T. amazonia (suggesting host specificity) or of Urochloa (suggesting absence of specificity/importance of local environment). After two years, pasture-grown T. amazonia seedlings were colonized by neither community, but rather by a species of Glomus that was rarely observed on the other plants. These results suggest that conspecific seedlings planted into existing vegetation generate a distinct mycorrhizal community that may influence competitive interactions and the relative costs and benefits of the AM fungal symbiosis at early stages in the life cycle of tropical trees.
Collapse
Affiliation(s)
- Laura Aldrich-Wolfe
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853, USA.
| |
Collapse
|