D. M. Sylvia

Pennsylvania State University, University Park, Maryland, United States

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Publications (35)57.93 Total impact

  • Abid Al Agely, David M Sylvia
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    ABSTRACT: Sea oats (Uniola paniculata L.) are the dominant plant in the pioneer coastal dunes of Florida and are widely used for dune restoration. DNA analysis has revealed significant ecotypic variation among Atlantic and Gulf coast populations of sea oats, but little is known about the diversity of the arbuscular mycorrhizal (AM) communities present in the dune systems. In a prior greenhouse study, we evaluated the functional diversity that exists among the AM fungal communities from divergent Florida dunes and selected effective host/AM fungus combinations for further study. The objective of this study was to evaluate the effect of these compatible combinations on the growth of sea oats planted at Anastasia State Recreation Area (AN) on the Atlantic coast and St. George Island State Park (SG) on the Gulf coast. Micropropagated sea oats from each site were inoculated with AM fungal communities also from AN and SG or a microbial filtrate control. The complete factorial of treatment combinations were grown in the greenhouse for 8 weeks and outplanted to the AN and SG field sites. After 1 year, root colonization was evaluated, and after 2 years, root colonization, shoot and root dry masses, and shoot- and root-P contents were determined. Overall, sea oats planted at AN had greater percent root colonization, shoot dry mass, and shoot-P content than those planted at SG. At AN, the local sea oat ecotype responded more to the fungal community from the same site relative to shoot dry mass and shoot-P content. At SG, the local fungal community produced larger plants with greater P content regardless of the origin of the host. We conclude that sea oat productivity is responsive to AM fungal ecotype as well as host ecotype, and fungal origin should therefore be taken into account when planning sea oat plantings on coastal dunes.
    Mycorrhiza 07/2008; 18(5):257-61. · 2.96 Impact Factor
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    I Ipsilantis, D M Sylvia
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    ABSTRACT: Microorganisms have been proposed as early indicators of wetland change; however, there is often too little information to reliably use microbial parameters for this purpose. The objective of this study was to document how nutrient loading, plant community, and season affected arbuscular mycorrhizal (AM) fungi (expressed as percent colonized root length), other fungi (estimated by ergosterol concentration), and bacteria (quantified by direct counts) in soil and detritus, and thereby to broadly evaluate the potential of native microorganisms to serve as indicators of wetland integrity. Dominant wetland plant communities (Panicum, Cladium, Typha, Salix, mixed herbaceous, and deep-water slough) were sampled seasonally from nutrient-impacted and reference areas of a central Florida wetland with historic nutrient loading (only Cladium occurred in both impacted and reference areas). Nutrient impact increased soil and detrital ergosterol and bacterial counts in some plant communities and seasons (e.g., Cladium sampled in the fall); however, the nutrient effect was confounded by interactions with the plant community and season. Nutrient impact reduced AM root colonization in samples from impacted compared to reference Cladium communities during summer and fall; however, there were again significant interactions with season and other plant communities. We conclude that before soil fungi and bacteria can be used as indicators of wetland integrity background values for each plant community and season need to be well documented.
    Applied Soil Ecology - APPL SOIL ECOL. 01/2007; 35(2).
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    I Ipsilantis, D M Sylvia
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    ABSTRACT: Arbuscular mycorrhizal (AM) fungi are known to exist in wetlands, but little is known about their function in these environments. We conducted greenhouse experiments to study the effects of AM fungal assemblages—collected from different vegetation communities in a Florida wetland-under free-drained and flooded conditions, and at three phosphorus (P) levels on growth and P nutrition of Typha latifolia L. and Panicum hemitomon Schult. We also studied the effects of flooding on the spread of extraradical hyphae from P. hemitomon roots. For both plants no AM fungal assemblage had a consistent effect on plant growth and P nutrition. For T. latifolia, flooding nearly eliminated AM fungal colonization and, in the free-drained treatments, P amendment suppressed colonization. Furthermore, colonization by some mycorrhizal assemblages increased shoot-and root-P concentrations, but there were no significant plant growth responses. For P. hemitomon, the mycorrhizal association was suppressed by flooding and P amendment but, among the fungal assemblages, there were differences in root colonization. Mycorrhizal colonization improved some plant-growth and P-nutrition parameters at lower P levels relative to nonmycorrhizal controls, but generally conferred no benefit or was detrimental at higher P levels. Extraradical hyphae of most assemblages were restricted by flooding to 2.5 cm, though differences among AM fungal assemblages occurred with a maximum observed extension of 16.5 cm. We conclude that the impact of the mycorrhizal association on these wetland plants was a function of the complex interactions among the AM fungal assemblages, plant species, water condition, and P level. Future studies should focus on understanding the species composition of the assemblages, and potential adaptation to wetland conditions among these fungal species.
    Applied Soil Ecology - APPL SOIL ECOL. 01/2007; 35(2).
  • D. M. SYLVIA, N. C. SCHENCK
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    ABSTRACT: Sporulation of Gigaspora margarita, Glomus clarum, Gl, mosseae and Gi. Heterogama was increased significantly after established pot cultures of bahiagras were drenched with superphosphate. However, sporulation of Gl. Etunicatum, Gl. Macrocarpum and Gi. Gigantean was reduced by the superphosphate drench. Generally, improved sporulation after application of superphosphate was associated with phosphorus (P)-tolerance of the mycorrhizl fungi. Gigaspora margarita, Gl. Clarum and Gl. Mosseae could colonize roots in soil that had 199 mg kg −1of acid-extractable P. The other fungi could not colonize roots in this high-P soil. Removal of shoots, application of herbicide, and stresses from drought and exposure to cold and dark did not affect spore numbers significantly.
    New Phytologist 05/2006; 95(4):655 - 661. · 6.74 Impact Factor
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    Abid Al Agely, David M Sylvia, Lena Q Ma
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    ABSTRACT: Chinese brake fern (Pteris vittata L.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well-documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg(-1)) and P (0, 25, and 50 mg kg(-1)) and with and without Chinese brake fern colonized by a community of AM fungi from an As-contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As-contaminated soils, the mycorrhizal status of ferns needs to be taken into account.
    Journal of Environmental Quality 01/2005; 34(6):2181-6. · 2.35 Impact Factor
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    ABSTRACT: Colonization of roots and soil by arbuscular mycorrhizal (AM) fungi sometimes promotes stomatal conductance (gs) of the host plant, but scientists have had difficulty predicting or manipulating the response. Our objective was to test whether the magnitude of AM influence on gs is related to environmental conditions: irradiance, air temperature or leaf temperature. Stomatal conductances of two groups of uncolonized sorghum plants were compared to gs of plants colonized by Glomus intraradices (Gi) or Gigaspora margarita (Gm) in 31 morning and afternoon periods under naturally varying greenhouse conditions. Stomatal conductance of Gi and Gm plants was often markedly higher than gs of similarly sized nonAM plants. AM promotion of gs was minimal at the lowest irradiances and lowest air and leaf temperatures, but was substantial at intermediate irradiance and temperatures. AM promotion was again low or absent at the highest irradiances and temperatures. Magnitude of AM promotion of gs was not a function of absolute gs. Promotion of gs by Gi and Gm was remarkably similar. Differing phosphorus fertilization did not affect gs.
    Mycorrhiza 05/2004; 14(2):85-92. · 2.96 Impact Factor
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    ABSTRACT: There is growing appreciation of arbuscular mycorrhizal effects on soil properties and their potential conse- quences on plant behavior. We examined the possibility that mycorrhizal soil may directly influence plant water rela- tions. Using wild-type and noncolonizing bean mutants planted into soils previously produced using mycorrhizal or nonmycorrhizal sorghum plants, we partitioned mycorrhizal influence on stomatal conductance and drought resistance into soil and root components, testing whether effects of mycorrhizal fungi occurred mostly via mycorrhization of roots, mycorrhization of soil, or both. The mutation itself had no effect on any water relations parameter. Colonization by Gigaspora margarita Gerdemann & Trappe and Glomus intraradices Schenck & Smith had appreciable effects on leaf water potential at the lethal point and on osmotic adjustment, relative to nonmycorrhizal plants of comparable size. Mycorrhizal effects on drought resistance were attributable to an effect on the plant itself rather than to an effect of mycorrhizal soil. Mycorrhizal effects on stomatal conductance were attributable to mycorrhization of both roots and soil, as well as to mycorrhization of roots alone. Surprisingly, merely growing in a mycorrhizal soil resulted in promo- tion of stomatal conductance of nonmycorrhizal plants in both amply watered and droughted plants. Mycorrhizal effects on droughted plants did not appear to be related to altered soil water retention properties, as Gigaspora margarita and Glomus intraradices altered the soil's moisture characteristic curve only slightly.
    Canadian Journal of Botany-revue Canadienne De Botanique - CAN J BOT. 01/2004; 82(4):503-514.
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    ABSTRACT: Mycorrhizal symbiosis can modify plant response to drying soil, but little is known about the relative contribution of soil vs. root hyphal colonization to drought resistance of mycorrhizal plants. Foliar dehydration tolerance, characterized as leaf and soil water potential at the end of a lethal drying episode, was measured in bean plants (Phaseolus vulgaris) colonized by Glomus intraradices or by a mix of arbuscular mycorrhizal fungi collected from a semi-arid grassland. Path analysis modeling was used to evaluate how colonization rates and other variables affected these lethal values. Of several plant and soil characteristics tested, variation in dehydration tolerance was best explained by soil hyphal density. Soil hyphal colonization had larger direct and total effects on both lethal leaf water potential and soil water potential than did root hyphal colonization, root density, soil aggregation, soil glomalin concentration, leaf phosphorus concentration or leaf osmotic potential. Plants colonized by the semi-arid mix of mycorrhizal fungi had lower lethal leaf water potential and soil water potential than plants colonized by G. intraradices. Our findings support the assertion that external, soil hyphae may play an important role in mycorrhizal influence on the water relations of host plants.
    Journal of Plant Physiology 11/2003; 160(10):1147-56. · 2.70 Impact Factor
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    ABSTRACT: Micropropagation technology promises to improve the supply of sea oats for restoring Florida's eroded beaches, but concerns about genetic diversity need to be addressed. These dune plants are colonized by a wide array of arbuscular mycorrhizal (AM) fungi, yet little is know of the diversity of these fungal communities. Our goal was to test the level of functional diversity that exists among communities of AM fungi that are present in divergent Florida dunes. Community pot cultures were established from samples collected from ten transects in two Gulf coast and two Atlantic coast locations in Florida, and these were used to conduct two greenhouse studies. The objective of the first study was to evaluate within-location variance in the mycorrhizal function of different AM fungal communities associated with endemic sea oats. The objective of the second study was to evaluate among-location responses of plant and fungal ecotypes using selected combinations obtained from the first experiment. Within locations, the AM fungal community had significant impacts on shoot mass and shoot-P contents, confirming a range of symbiotic effectiveness exists within the beach-dune system. Among locations, there was a tendency for greater root colonization between host clones and fungal communities from the same location, indicating a degree of specificity between host ecotypes and their symbiotic fungi. Relative to plant growth response, one fungal community was superior across plant genotypes from all locations, while one plant genotype tended to have the best response across all fungal communities. These data suggest that while it is possible to select effective AM fungal-host combinations for outplanting, origin of host and AM fungi have little predictive value in screening these combinations.
    Mycorrhiza 09/2003; 13(4):177-83. · 2.96 Impact Factor
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    ABSTRACT: A strip-tillage production system for tomatoes (Lycopersicon esculentum Mill.) is impacted by nutrient competition from bahiagrass (Paspalum notatum Flgge). Tomato and bahiagrass differ in mycorrhizal responsiveness and our objective was to evaluate the influence of arbuscular mycorrhizal (AM) fungi on the competitive pressure of bahiagrass on growth of tomato. The first experiment evaluated the effect of bahiagrass competition, soil pasteurization, and AM fungal inoculation on tomato growth, P content, and root colonization in a low-P soil. Tomato grown alone was very responsive to mycorrhizal colonization - shoot dry mass of inoculated plants was up to 243% greater than that of noninoculated plants. Tomato grown with bahiagrass had reduced root and shoot growth across all treatments compared with tomato grown alone, but there was an increase in shoot mass following AM fungal inoculation across both pasteurized and nonpasteurized treatments resulting in a >50% increase in shoot dry mass of tomato compared to noninoculated controls. A second experiment was conducted to test bahiagrass competition, soil pasteurization, AM fungal inoculation, and P amendment on tomato growth in a moderate-P soil. With bahiagrass competition and no P addition, inoculation increased root mass by 115% and shoot mass by 133% in pasteurized soil; however, with the application of 32 mg P kg-1 the trend was reversed and inoculated plants were smaller than noninoculated controls. We conclude that the role of mycorrhizae in plant competition for nutrients is markedly impacted by soil nutrient status and reduced P application may allow tomatoes to take advantage of their inherent responsiveness to mycorrhizae in a low to moderate soil-P environment.
    Biology and Fertility of Soils 01/2001; 34(6):448-452. · 2.51 Impact Factor
  • David M. Sylvia
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    ABSTRACT: Mineralization is the dominant process controlling soil-solution P in the Spodosols of the southeastern United States. Pine trees growing in these soils are typically colonized by ectomycorrhizal (EM) fungi that are known to produce phosphatases. Little, however, is known of the dynamics of EM short roots or phosphatase activity in tree plantations. To address this question, short root densities, EM morphotypes, and associated surface acid phosphomonoesterase in a 12-year-old Pinus elliottii plantation in northern Florida were evaluated. The density of total (living and dead) short roots changed little from February through June, with a mean of 7.6 cm soil. The majority of the short roots, however, were inactive or dead with only 14 to 38% appearing viable upon visual inspection. The majority of the viable short roots were mycorrhizal. The most abundant morphotypes were formed by Cenococcum and Thelephora but these had low phosphatase activity. In contrast, less frequently observed morphotypes had substantially higher rates of enzyme production and these may play an important role in sustainable P nutrition of plantation trees.
    Journal of Sustainable Forestry 01/2000; 11(3):83-93.
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    ABSTRACT: An alternative, low-input production system for fresh market tomato was developed using strip tillage practices in conjunction with established bahiagrass pasture. The alternative system was designed to reduce the impact of soilborne pests, minimize agricultural inputs, improve soil conservation and optimize yields. Field experiments indicate that competition from bahiagrassfor nutrients within the tilled strips significantly impacted yield. Selective colonization of tomato roots by arbuscular mycorrhizal fungi isolated from field plots was observed. Damage from root-knot nematodes was minimized by planting tomato into established bahiagrass pastures. The alternative system was validated on a commercial tomato production farm in a side by side comparison with a conventional production system consisting of raised beds, fumigated with methyl bromide and covered by black polyethylene plastic. Yields were 6.5 t/ha greater under the conventional system. However, the net return was $568/ha greater in the alternative system. The results indicate that the alternative system has the potential to replace or supplement the conventional production system.
    American Journal of Alternative Agriculture. 05/1999; 14(02):59 - 68.
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    ABSTRACT:  Our objective was to evaluate the ability of an ectomycorrhizal fungus to alter the competitive interaction of pine seedlings growing with grass, and to determine whether the interaction was modified by soil-phosphorus (P) concentration. Slash pine (Pinus elliottii), inoculated with the ectomycorrhizal fungus Pisolithus arhizus or fortuitously colonized by Thelephora terrestris, and a native grass (Panicum chamaelonche) were grown in a greenhouse at three P levels (0.32, 3.22, 32.26 μM H3PO4). Pine inoculated with P. arhizus took up more P when competing with the nonmycorrhizal grass than when competing with another pine (irrespective of pine mycorrhizal status). Phosphorus uptake kinetics (Cmin, the minimum concentration at which P can be absorbed from a solution; Imax, the maximum uptake rate) for pine and grass were also determined under hydroponic conditions. Pine had a higher Imax than grass but grass had a lower Cmin, suggesting that pine is more competitive at higher nutrient concentrations while grass is more competitive at lower nutrient concentrations. The controlled conditions used in these experiments allowed us to evaluate specific parameters (P uptake and absorbing surface area) affecting plant competition.
    Mycorrhiza 01/1999; 9(4):199-204. · 2.96 Impact Factor
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    ABSTRACT:  Applications of high levels of MgSO4 resulted in reduced root colonization and sporulation by Glomus sp. (INVAM isolate FL329) with sweet potato and onion in aeroponic and sand culture, respectively. Onion shoot-Mg concentrations were elevated when a nutrient solution containing 2.6 or 11.7 mm MgSO4 was applied. Magnesium application depressed tissue-Ca levels. With lower Ca in the tissue, colonization was reduced from > 30% of root length to < 10%, and sporulation from > 1200 to ca. 200 spores per plant, 10 weeks after transplantation and the start of nutrient application. These effects on colonization and sporulation were independent of changes in tissue-P concentration. High Mg/low Ca tissue concentrations induced premature root senescence, which may have disrupted the mycorrhizal association. Our results confirm the importance of Ca for the maintenance of a functioning mycorrhiza.
    Mycorrhiza 01/1998; 7(5):237-242. · 2.96 Impact Factor
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    ABSTRACT: Mycorrhizal associations provide a linkage between tree roots and the soil, thereby contributing to the tolerance of trees to environmental stresses. Little, however, is known about the mycorrhizal status or dependency of many landscape trees. The objective of this study was to quantify mycorrhizal root colonization and spore formation on a diverse collection of ornamental tree species grown in raised beds or containers at an established tree farm in central Florida. In addition, root diameters were measured to determine if there was a relationship between this parameter and mycorrhizal formation. A total of 23 tree species were sampled; 9 were present both in containers and raised beds, 6 species were present in containers only, and 8 species were present as embedded plants only. The proportion of root length colonized by mycorrhizal fungi ranged from 0% to 83%. Mean arbuscular mycorrhizal spore numbers ranged from 1,000 \im (0.0197 to 0.0394 in.). No relationship was found between root coarseness and mycorrhizal root colonization or sporulation. The majority of trees formed mycorrhizae of the arbuscular type. Five species in the family Pinaceae or Fagaceae had the potential to form ectomycorrhizae; however, they were poorly colonized. Future research should be directed toward understanding the importance of mycorrhizae to landscape trees, including effects on tree survival and growth and the effect of fertilizer and pesticide applications on mycorrhizal development.
    01/1998;
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    David J. Farmer, David M. Sylvia
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    ABSTRACT: Amplification of the internal transcribed spacer (ITS) of ribosomal RNA genes using PCR and subsequent RFLP analysis offers promise for improved species-level identification of ectomycorrhizal fungi. Intrageneric homogeneity and intraspecific heterogeneity of these characters are, however, frequent. A diverse group of ectomycorrhizal fungi with worldwide distribution was characterized by ITS-RFLP analysis. DNA of 64 identified and five unknown ectomycorrhizal fungi was extracted and their ITS regions were selectively amplified with ITS1-F and ITS4 ribosomal RNA gene primers. Each PCR product was digested with seven restriction enzymes. The resulting restriction fragments were compared by distance matrix analysis. Restriction enzyme analysis of amplified fragments was sufficient for distinguishing all but two closely related species. Intraspecific variation was observed in Cenococcum geophilum and Pisolithus arhizus, providing further evidence that these taxa represent species complexes.
    Mycological Research. 01/1998;
  • C. T. Pedersen, D. M. Sylvia
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    ABSTRACT: Arbuscular mycorrhizal (AM) grasses compete for nutrients with ectomycorrhizal (EM) pine in the southeastern United States. Our objective was to determine if benomyl could be used to selectively inhibit the function of AM and thereby reduce grass competition in the field. The effects of Benlate (active ingredient: benomyl) in the greenhouse and field were evaluated. No effect was observed on pine inoculated with Pisolithus tinctorius in the greenhouse. Colonized root length of benomyl-treated Zea mays L. plants inoculated with Glomus sp. in the greenhouse remained static over time and the response was not dose dependent at concentrations of 0, 20, 60 and 150kg benomyl ha–1 equivalent. In contrast, colonization of nontreated plants increased over time. In the field, a minimal reduction of grass colonization was observed following four applications of benomyl ranging from 5 to 20kgha–1. We conclude that benomyl can successfully inhibit development of AM fungi under controlled conditions in the greenhouse with no inhibitory effects on the EM fungus P. tinctorius; however, in the field several factors may interfere with the effect of benomyl on AM fungi. These factors include: (a) the presence of ground cover which obstructs penetration of the fungicide to the soil, (b) timing of application in relation to mycorrhizal development, and (c) the application method of benomyl, a soil drench being preferable to a foliar spray.
    Biology and Fertility of Soils 07/1997; 25(2):163-168. · 2.51 Impact Factor
  • J. V. D. ROUSSEAU, D. M. SYLVIA, A. J. FOX
    New Phytologist - NEW PHYTOL. 01/1994; 128(4):639-644.
  • D. M. Sylvia, A. G. Jarstfer, M. Vosátka
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    ABSTRACT: For efficient use of mycorrhizal inoculum the effectiveness of the isolate used and the rate of application required for maximum colonization must be known. The objectives of this research were to (1) define the lower limit of inoculum density required for maximum colonization of Uniola paniculata in a commercial nursery and (2) evaluate the performance of a selected native dune vesicular-arbuscular mycorrhizal (VAM) isolate versus a commercially available non-dune VAM (foreign) isolate on three diverse Florida beaches. An inoculum-dilution study was conducted in a commercial nursery with cutroot inoculum of a Glomus sp. that had been isolated from a Florida dune. Maximum colonization was achieved with approximately 1 propagule ml-1 of growth medium. In a separate nursery study, 10 inoculation treatments (combinations of inoculum source and level) were established in the commercial nursery. Treatments included cut-root and sheared-root inoculum of the native dune isolate, and Nutri-Link, a commercial inoculum of G. intraradices. Colonized plants from selected treatments were transplanted to beach sites around Florida. At Miami Beach, after one growing season, the shoot mass of plants inoculated with the native isolate was approximately twice that of plants inoculated with the foreign isolate. At Katherine Abbey Hanna Park and Eglin Air Force Base there were no significant inoculum source effects on shoot mass or root length after one growing season. However, the native isolate produced a greater colonized root length than the foreign isolate in all plantings. The soil hyphal density was measured at Eglin Air Force Base, and the results showed that plants inoculated with the native isolate had more soil hyphae (4.33 mg-1) than plants inoculated with the foreign isolate (3.65 mg-1) or the non-inoculated plants (2.12 mg-1). Even where there were no obvious shoot growth responses, mycorrhizal inoculation may have an important effect on dune stabilization, as soil hyphae are known to bind sand grains and improve dune stability.
    Biology and Fertility of Soils 06/1993; 16(2):139-144. · 2.51 Impact Factor
  • D. M. O'Keefe, D. M. Sylvia
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    ABSTRACT: To better understand the behavior of selected vesicular-arbuscular mycorrhizal (VAM) isolates in the field, we documented the growth of roots, root hairs, and VAM colonization of inoculated and noninoculated sweet potato plants (Ipomea batatas (L.) Lam. cv White Star) over a growing season. We also determined the seasonal dynamics of P and Zn uptake, and shoot and storage-root growth. Shoot cuttings were inoculated with an isolate of either Glomus etunicatum Becker and Gerdemann or Acaulospora rugosa Mortan, or were not inoculated, and were harvested 2, 4, 8, 13, 20, and 27 weeks after planting (WAP). At each harvest, roots were sampled at 0 to 30, 30 to 60, and 60 to 90 cm depths and at 0, 23, 83, and 116 cm from the base of the shoot. At the end of the study, the roots of three non-inoculated plants were sampled by soil horizon. Inoculation had no affect on shoot growth or total shoot uptake of P and Zn; shoot dry mass and P and Z content increased rapidly up to 20 WAP, while shoot length continued to increase through 27 WAP. Shoot-P concentration of plants inoculated with A. rugosa at 2 and 8 WAP were higher than the noninoculated plants, while shoot-Zn concentration was not affected by inoculation. Storage-root yields of inoculated plants were higher than yields for noninoculated plants. Root length density, and percentage of root length with root hairs and VAM colonization were highest and most dynamic near the base of the plant. Percentage of root length colonization by VAM fungi was highest in the E2 horizon, intermediate in the Bh horizon, and lowest in the Ap horizon. Percentage of root length with root hairs had the opposite pattern. Intensive measurements of root characteristics close to the base of the plant, and shoot P-content and concentration during the period of rapid yield production, provided the most useful data for evaluating the activity of effective isolates.
    Mycorrhiza 01/1993; 3(3):115-122. · 2.96 Impact Factor

Publication Stats

555 Citations
57.93 Total Impact Points

Institutions

  • 2007–2008
    • Pennsylvania State University
      • Department of Ecosystem Science and Management
      University Park, Maryland, United States
  • 1983–2008
    • University of Florida
      • • Department of Soil and Water Science
      • • Department of Plant Pathology
      Gainesville, FL, United States
  • 2004
    • The University of Tennessee Medical Center at Knoxville
      Knoxville, Tennessee, United States