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Lynne Boddy - One of the best experts on this subject based on the ideXlab platform.
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Resource acquisition by the Mycelial‐Cord‐former Stropharia caerulea: effect of resource quantity and quality
FEMS Microbiology Ecology, 2006Co-Authors: Damian P Donnelly, Lynne BoddyAbstract:Saprotrophic Mycelial-Cord-forming basidiomycetes, which extend between organic substrata on the forest floor, exhibit remarkable patterns of reallocation of biomass and nutrients when encountering new resources. These have been equated with foraging strategies, and differ between species, resources quality and quantity. Stropharia caerulea occupies more disturbed sites than the fungi previously examined, and the responses of its Mycelial foraging systems were investigated non-destructively by image analysis. Resource quantity and quality affected extension rate, extra-resource biomass production and distribution, as quantified by box-count fractal dimension. When mycelia grew from 0.5 cm3 beech (Fagus sylvatica) wood inocula across compressed, non-sterile soil to 0.06–4 cm3 uncolonised sterile beech wood "baits" extension rate fell after contact with large wood baits but biomass production and Mycelial distribution was unaffected. In contrast, extension rates of Cord systems grown from 0.15 cm3U. dioica rhizome inocula to 0.1–1.2 cm3 rhizome "baits" were unaffected after contact with equal or larger sized baits, but biomass production rates fell and mass fractal dimension increased. Mycelial morphology was affected by inoculum age; systems grown from 84 day old 0.5 cm3 beech wood inocula took 10 days longer achieving the fractal values of systems developing from 22 day old inocula. Foraging strategies and resource relations of Mycelial Cord systems are discussed.
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Nutrient Movement and Mycelial Reorganization in Established Systems of Phanerochaete velutina, Following Arrival of Colonized Wood Resources
Microbial Ecology, 2005Co-Authors: Melanie J Harris, Lynne BoddyAbstract:The effect of arrival of wood resources, precolonized by Coriolus versicolor , Phlebia radiata , Stereum hirsutum , and Vuilleminia comedens , on Mycelial systems of Phanerochaete velutina was studied in trays of nonsterile soil in the laboratory over 5 months. Morphological responses were quantified nondestructively using image analysis. In a parallel series of experiments, nutrient movement was also quantified nondestructively using ^32P monitoring with a scintillation probe and subsequently by destructively harvesting after 155 days. The presence of a fungus occupying a newly arriving resource had major effects on deployment of biomass and on the uptake and allocation of phosphorus in the established Pha. velutina system. The effects varied depending on the species occupying the new resource. Hyphal coverage was greater in the half of the system to which new resources were added. Following addition of new resources, there was massive redeployment of biomass away from regions with no new resource when the new resource was (1) uncolonized, (2) colonized by V. comedens , or (3) colonized by S. hirsutum (although to a lesser extent with the latter), but not with others. ^32P was taken up by Pha. velutina both in the vicinity of the inoculum and the new resource and was translocated to the new resource from both sites of uptake; however, the local supply contributed most. Bidirectional translocation also occurred. The results are discussed in relation to Mycelial foraging strategies, nutrient translocation, and partitioning within Mycelial Cord systems.
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Soil water potential shifts: developmental responses and dependence on phosphorus translocation by the saprotrophic, Cord-forming basidiomycete Phanerochaete velutina
Fungal Biology, 2001Co-Authors: John M Wells, Joanna Thomas, Lynne BoddyAbstract:Mycelial Cord systems, of the basidiomycete Phanerochaete velutina , a common woodland saprotroph, were grown on unsterile soil in model laboratory microcosms from 4 cm 3 wood inocula. Systems were supplied after 37 d with a fresh 4 cm 3 beech wood ‘bait’, placed behind the foraging colony margin. Systems were subject to dry shift (— 0.056 MPa) or wet shift (— 0.009 MPa) over an 11d period either immediately after, or 20 d after baits were supplied. Controls were maintained at constant soil matric potential (— 0.019 MPa). 57-d-old systems were supplied with NH 4 K 2 PO 4 including 32 P tracer within soil compartments local to inoculum or bait. Image analysis was used to quantify morphological responses to water regime and resource supply, and tracer movement monitored non-destructively with a scintillation probe for 57 d. 32 P uptake was greatest when tracer was supplied local to the inoculum. Dry shift concurrent with bait supply caused system wide Cord-thickening, prevented polarised growth towards the newly supplied bait, had a significant carbon (energy) cost compared to controls, significantly reduced 32 P acquisition, and significantly increased 32 P relocation to the bait. Wet shift concurrent with bait supply caused considerable loss of extra-resource mycelium in the unbaited region, resulting in highly polarised development along the bait-inoculum line, but did not affect 32 P uptake and partitioning. Delayed wet shift caused swifter polarisation towards the bait, quantified in terms of fractal dimension, did not result in system wide regression of extra-resource mycelium, and resulted in correspondingly increased rates of 32 P acquisition. Delayed dry shift prevented polarised growth towards the bait and had only transient effects on 32 P uptake and partitioning. Results suggest that resource capture took priority over coordination of C reserves and reallocation of Mycelial effort, and that mycelium colonising the new resource was more dependent on P translocate during desiccation stress.
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dynamics of Mycelial growth and phosphorus partitioning in developing Mycelial Cord systems of phanerochaete velutina dependence on carbon availability
New Phytologist, 1999Co-Authors: John M Wells, Melanie J Harris, Lynne BoddyAbstract:Mycelial Cord systems, up to 50 cm in diameter, of the basidiomycete Phanerochaete velutina, a common woodland saprotroph, were grown on unsterile soil in model laboratory microcosms from either 4 or 16 cm3 wood inocula. After 48 d, systems were supplied at 10-d intervals with pairs of new 4 cm3 beechwood resources placed behind the foraging colony margin, where possible on opposite sides of the system. Image analysis was used to quantify radial extension, hyphal cover, the mass (DBM) and surface fractal (DBS) dimensions of the Mycelial systems and wood-resource bleaching activity. Mycelial systems developing from small inocula had significantly (P0.05) lower radial extension rates, hyphal cover and DBM∶DBS ratio than those from large inocula. Initially, systems developing from small inocula also displayed significantly (P 0.05) affected by inoculum resource size. However, the proportion of total acquired P allocated to resources, which varied acCording to the length of time that resources had been in contact with the mycelium, was dependent upon inoculum size. The results support the hypothesis that phosphorus translocation is not a demand-driven process. We suggest that the time taken before the greatest rate of phosphorus withdrawal from a uniform translocation stream is dependent upon prior availability of carbon within colonized resources.
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Temporary phosphorus partitioning in Mycelial systems of the Cord‐forming basidiomycete Phanerochaete velutina
New Phytologist, 1998Co-Authors: John M Wells, Melanie J Harris, Lynne BoddyAbstract:Mycelial Cord systems, up to 50-cm diameter, of the basidiomycete Phanerochaete velutina (DC.: Pers.) Parmasto, a common woodland saprotroph, grown on non-sterile soil in model laboratory microcosms were baited, after 27 d, with pairs of fresh beech wood blocks (baits), placed at 10 d intervals behind the foraging colony margin. System development was quantified by image analysis. Mean radial extent and hyphal cover increased linearly with time until day 21, but declined before the Mycelial systems reached the edges of the laboratory microcosms. The mass (DBM) and border (DBS) fractal dimensions of the Mycelial systems changed with time but the ratio DBM∶DBS became constant after 14 d. A separate central compartment containing the inoculum was supplied with 32P orthophosphate and its translocation to wood baits monitored non-destructively for 73 d. Whilst total 32P acquisition by wood baits increased linearly with time, the proportion of total allocated to baits varied significantly both temporally and acCording to the length of time that baits had been in contact with the mycelium. Most recently supplied wood baits were not the main sink for supplied phosphorus; rather, the rate of 32P acquisition was initially greatest in baits from which egress of the fungus had already occurred. The rate of 32P acquisition by the most recently added baits increased with time, supported by efflux from other wood baits, which had initially been the main sinks for translocated phosphorus. The results raise important questions about the ecological and functional significance of nutrient partitioning in Cord systems and imply that ‘observed’ translocation, rather than being an absolute measure, indicates the degree to which phosphorus is loaded from a translocation stream in regions where it is being actively utilized and/or stored.
John M Wells - One of the best experts on this subject based on the ideXlab platform.
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Soil water potential shifts: developmental responses and dependence on phosphorus translocation by the saprotrophic, Cord-forming basidiomycete Phanerochaete velutina
Fungal Biology, 2001Co-Authors: John M Wells, Joanna Thomas, Lynne BoddyAbstract:Mycelial Cord systems, of the basidiomycete Phanerochaete velutina , a common woodland saprotroph, were grown on unsterile soil in model laboratory microcosms from 4 cm 3 wood inocula. Systems were supplied after 37 d with a fresh 4 cm 3 beech wood ‘bait’, placed behind the foraging colony margin. Systems were subject to dry shift (— 0.056 MPa) or wet shift (— 0.009 MPa) over an 11d period either immediately after, or 20 d after baits were supplied. Controls were maintained at constant soil matric potential (— 0.019 MPa). 57-d-old systems were supplied with NH 4 K 2 PO 4 including 32 P tracer within soil compartments local to inoculum or bait. Image analysis was used to quantify morphological responses to water regime and resource supply, and tracer movement monitored non-destructively with a scintillation probe for 57 d. 32 P uptake was greatest when tracer was supplied local to the inoculum. Dry shift concurrent with bait supply caused system wide Cord-thickening, prevented polarised growth towards the newly supplied bait, had a significant carbon (energy) cost compared to controls, significantly reduced 32 P acquisition, and significantly increased 32 P relocation to the bait. Wet shift concurrent with bait supply caused considerable loss of extra-resource mycelium in the unbaited region, resulting in highly polarised development along the bait-inoculum line, but did not affect 32 P uptake and partitioning. Delayed wet shift caused swifter polarisation towards the bait, quantified in terms of fractal dimension, did not result in system wide regression of extra-resource mycelium, and resulted in correspondingly increased rates of 32 P acquisition. Delayed dry shift prevented polarised growth towards the bait and had only transient effects on 32 P uptake and partitioning. Results suggest that resource capture took priority over coordination of C reserves and reallocation of Mycelial effort, and that mycelium colonising the new resource was more dependent on P translocate during desiccation stress.
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dynamics of Mycelial growth and phosphorus partitioning in developing Mycelial Cord systems of phanerochaete velutina dependence on carbon availability
New Phytologist, 1999Co-Authors: John M Wells, Melanie J Harris, Lynne BoddyAbstract:Mycelial Cord systems, up to 50 cm in diameter, of the basidiomycete Phanerochaete velutina, a common woodland saprotroph, were grown on unsterile soil in model laboratory microcosms from either 4 or 16 cm3 wood inocula. After 48 d, systems were supplied at 10-d intervals with pairs of new 4 cm3 beechwood resources placed behind the foraging colony margin, where possible on opposite sides of the system. Image analysis was used to quantify radial extension, hyphal cover, the mass (DBM) and surface fractal (DBS) dimensions of the Mycelial systems and wood-resource bleaching activity. Mycelial systems developing from small inocula had significantly (P0.05) lower radial extension rates, hyphal cover and DBM∶DBS ratio than those from large inocula. Initially, systems developing from small inocula also displayed significantly (P 0.05) affected by inoculum resource size. However, the proportion of total acquired P allocated to resources, which varied acCording to the length of time that resources had been in contact with the mycelium, was dependent upon inoculum size. The results support the hypothesis that phosphorus translocation is not a demand-driven process. We suggest that the time taken before the greatest rate of phosphorus withdrawal from a uniform translocation stream is dependent upon prior availability of carbon within colonized resources.
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temporary phosphorus partitioning in Mycelial systems of the Cord forming basidiomycete phanerochaete velutina
New Phytologist, 1998Co-Authors: John M Wells, Melanie J Harris, Lynne BoddyAbstract:Mycelial Cord systems, up to 50-cm diameter, of the basidiomycete Phanerochaete velutina (DC.: Pers.) Parmasto, a common woodland saprotroph, grown on non-sterile soil in model laboratory microcosms were baited, after 27 d, with pairs of fresh beech wood blocks (baits), placed at 10 d intervals behind the foraging colony margin. System development was quantified by image analysis. Mean radial extent and hyphal cover increased linearly with time until day 21, but declined before the Mycelial systems reached the edges of the laboratory microcosms. The mass (DBM) and border (DBS) fractal dimensions of the Mycelial systems changed with time but the ratio DBM∶DBS became constant after 14 d. A separate central compartment containing the inoculum was supplied with 32P orthophosphate and its translocation to wood baits monitored non-destructively for 73 d. Whilst total 32P acquisition by wood baits increased linearly with time, the proportion of total allocated to baits varied significantly both temporally and acCording to the length of time that baits had been in contact with the mycelium. Most recently supplied wood baits were not the main sink for supplied phosphorus; rather, the rate of 32P acquisition was initially greatest in baits from which egress of the fungus had already occurred. The rate of 32P acquisition by the most recently added baits increased with time, supported by efflux from other wood baits, which had initially been the main sinks for translocated phosphorus. The results raise important questions about the ecological and functional significance of nutrient partitioning in Cord systems and imply that ‘observed’ translocation, rather than being an absolute measure, indicates the degree to which phosphorus is loaded from a translocation stream in regions where it is being actively utilized and/or stored.
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Temporary phosphorus partitioning in Mycelial systems of the Cord‐forming basidiomycete Phanerochaete velutina
New Phytologist, 1998Co-Authors: John M Wells, Melanie J Harris, Lynne BoddyAbstract:Mycelial Cord systems, up to 50-cm diameter, of the basidiomycete Phanerochaete velutina (DC.: Pers.) Parmasto, a common woodland saprotroph, grown on non-sterile soil in model laboratory microcosms were baited, after 27 d, with pairs of fresh beech wood blocks (baits), placed at 10 d intervals behind the foraging colony margin. System development was quantified by image analysis. Mean radial extent and hyphal cover increased linearly with time until day 21, but declined before the Mycelial systems reached the edges of the laboratory microcosms. The mass (DBM) and border (DBS) fractal dimensions of the Mycelial systems changed with time but the ratio DBM∶DBS became constant after 14 d. A separate central compartment containing the inoculum was supplied with 32P orthophosphate and its translocation to wood baits monitored non-destructively for 73 d. Whilst total 32P acquisition by wood baits increased linearly with time, the proportion of total allocated to baits varied significantly both temporally and acCording to the length of time that baits had been in contact with the mycelium. Most recently supplied wood baits were not the main sink for supplied phosphorus; rather, the rate of 32P acquisition was initially greatest in baits from which egress of the fungus had already occurred. The rate of 32P acquisition by the most recently added baits increased with time, supported by efflux from other wood baits, which had initially been the main sinks for translocated phosphorus. The results raise important questions about the ecological and functional significance of nutrient partitioning in Cord systems and imply that ‘observed’ translocation, rather than being an absolute measure, indicates the degree to which phosphorus is loaded from a translocation stream in regions where it is being actively utilized and/or stored.
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Wood decay and phosphorus translocation by the Cord‐forming basidiomycete Phanerochaete velutina: the significance of local nutrient supply
New Phytologist, 1998Co-Authors: John M Wells, Lynne Boddy, Damian P DonnellyAbstract:Mycelial Cord systems of Phanerochaete velutina (DC.: Pers.) Parmasto grown from 4 cm3 inocula on a nutrient-depleted non-sterile soil in compartmentalized laboratory microcosms were baited after 13 d of growth with either fresh, non-sterile 4 cm3 wood blocks or control Perspex® blocks of the same contact area. After 112 d, mature Mycelial systems, which were in senescent phase, were subjected to disturbance by supplying a new fresh wood bait diametrically opposite the existing bait and, after 126 d, to nutrient regime amendment by application of NPK solution. At harvest (186 d) there was a significant (P0·001) linear relationship between extra-resource Mycelial biomass and total wood decay over the preceding 74 d. Nutrient amendment alone did not significantly (P>0·05) affect extra-resource Mycelial biomass production or wood decay rates in either disturbed or undisturbed Cord systems. However, both Mycelial biomass production and resource decay were significantly (P0·05) enhanced when nutrient amendment and disturbance treatments were applied concurrently. Bi-directional phosphorus translocation to inocula and wood baits (determined non-destructively) was assessed by labelling the NPK solution applied distal or proximal to the initially supplied bait with 32P. In both disturbed and undisturbed Cord systems the rate of 32P uptake from a local supply was two orders of magnitude higher than from a distal supply. In disturbed Cord systems uptake of 32P by inocula, which were midway between the two radiotracer supply points, was significantly (P0·05) higher when the supply point contained a newly supplied wood bait. Net translocation of 32P to newly supplied wood baits increased with time at the expense of translocation to inocula and existing wood baits. The switch in direction of net phosphorus translocation, the importance of localized nutrient scavenging and the partitioning of wood decay are discussed in relation to the ecological significance of Mycelial Cords.
J M Wells - One of the best experts on this subject based on the ideXlab platform.
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translocation of soil derived phosphorus in Mycelial Cord systems in relation to inoculum resource size
FEMS Microbiology Ecology, 1995Co-Authors: J M Wells, Lynne BoddyAbstract:Abstract Uptake of 32 P phosphorus from soil was investigated in Mycelial Cord systems of Phanerochaete velutina, Hypholoma fasciculare, Tricholomopsis platyphylla and Phallus impudicus which extended from 0.5, 2, 4 or 8 cm 3 beech ( Fagus sylvatica ) inocula. Cord systems accumulated between 4.8 and 18.7% of phosphorus supplied to soil, acCording to species and size of inoculum. Phosphorus translocation to newly-colonized 2 cm 3 beech baits, determined non-destructively, was characterized by an initial steady phase, of 2.5 to 32 nmol P day −1 which lasted at least 12 days for all four species. After the initial steady phase, translocation rates declined. Initial Mycelial extension and wood decay rates also varied with species and inoculum size. There was no clear relationship between phosphorus translocation rates, wood decay or the distribution of soil-derived phosphorus in Cord system components. However, with increasing inoculum size, P. velutina systems allocated a significantly greater proportion of available phosphorus to newly-colonized baits. The degree to which distribution of soil-derived phosphorus in Cord systems is related to nutrient conservation or metabolic demand in the fungi is discussed.
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carbon translocation in Mycelial Cord systems of phanerochaete velutina dc pers parmasto
New Phytologist, 1995Co-Authors: J M Wells, Lynne Boddy, R EvansAbstract:SUMMARY Movement of radiotracer was monitored in Mycelial Cord systems developed from wood block inocula, pre-colonized by Phanerochaete velutina (DC: Pers.) Parmasto grown on unsterile soil. In short-term studies, reproducible but low-level loading of radiotracer was observed which was independent of the extent of Cord systems. Carbon translocation velocities ranged from 132 to 336 cm h-1, whilst fluxes were estimated to range from 35 to 66 nmol cm-2 h-1 (as glucose). When Cord systems were supplied with a range of potential carbon resources as baits considerable movement of carbon was detected over 9 wk. More than 80 % of exogenously supplied carbon was retained in resource units rather than being allocated to extra-resource mycelium. The direction and extent of carbon movement, and partitioning of decay between inocula and baits within Cord systems, was dependent upon the type and size of bait and whether or not combinations of baits included wood pre-colonized by other sapro trophic fungi. There was evidence for coordinated use of resources within Cord systems and that carbon movement was not a function of Mycelial growth. Respiratory carbon losses were greatest when baits included sterile leaf litter packs and least when sterile wood baits were supplied. The results are discussed in terms of nutrient conservation and cycling in Cord systems.
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effect of temperature on wood decay and translocation of soil derived phosphorus in Mycelial Cord systems
New Phytologist, 1995Co-Authors: J M Wells, Lynne BoddyAbstract:SUMMARY Uptake of 32P phosphorus from soil was investigated at 5–25 °C in Mycelial Cord systems of Phanerochaete velutina (D.C.: Pers.), Hypholoma fasciculare (Huds.: Fr.) Kummer and Phallus impudiciis (L.) Pers. which extended from 2cm3 beech (Fagus sylvatica) inocula, and which had initially developed at either 10 or 25 °C. Uptake of phosphorus from soil was opportunistic, being unaffected by the presence of additional wood resource units in Mycelial Cord systems. The magnitude of phosphorus uptake was dependent on species, temperature during uptake and the temperature at which Cord systems developed. Phosphorus translocation to newly colonized baits, determined non-destructively, was characterized by an initial rapid flux to a plateau in all three species. Initial rates of phosphorus translocation (up to 18·46 nmol P d-1) generally increased with temperature whilst total translocation was species and temperature dependent. There was evidence that both P. velutina and H. fasciculare displayed temperature acclimation, since phosphorus uptake and translocation at lower temperatures was greater in Cord systems which had developed initially at 10° compared with 25 °C. Mycelial extension and wood decay rates also varied with species, initial development temperature and subsequent incubation temperature, but did not correlate with the temperature profiles of phosphorus uptake and translocation. Results are discussed in relation to nutrient acquisition, conservation and cycling in basidiomycete Mycelial Cord systems.
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wood decay and phosphorus and fungal biomass allocation in Mycelial Cord systems
New Phytologist, 1990Co-Authors: J M Wells, Lynne BoddyAbstract:summary Wood block inocula, of different decay states, colonized by Phanerochaete velutina (D.C.: Pers.) Parmasto and Phallus impudicus (L.) Pers., were supplied with [32P]orthophosphate 1 wk after mycelium had made contact with newly supplied sterile wood baits. Inoculum decay state affected the initial pattern of Mycelial outgrowth, biomass, phosphorus uptake and subsequent decay rates of newly supplied baits. P. velutina and P. impudicus translocated up to 75 and 13 % respectively of phosphorus accumulated by the inoculum to the new supplied bait, translocation being in proportion to the decay state of the inoculum. On contact with baits, biomass was preferentially allocated to connective rather than non-connective mycelium. This was accompanied by regression of non-connective mycelium, which depended on the decay state of the inoculum. Phosphorus movement via connective Cords was up to ten times higher in non-connective Cords, maximal rates of 7225 nmol P cm−2 d−1 being reCorded for Cords from the most decayed P. velutina inocula.
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the fate of soil derived phosphorus in Mycelial Cord systems of phanerochaete velutina and phallus impudicus
New Phytologist, 1990Co-Authors: J M Wells, C L Hughes, Lynne BoddyAbstract:SUMMARY This study demonstrated the direct uptake of [32P]phosphorus from soil by ‘foraging’ Cord systems of Phanerochaete velutina (DC: Pers.) Parmasto and Phallus impudicus (L.) Pers., grown from 4 cm3beech (Fagus sylvatica L.) wood inocula. Total uptake was independent of, but ‘allocation’ within Cord systems dependent on, species, the state of decay of wood inocula, and phosphorus availability in different parts of Cord systems. Cords were shown to be functional pathways for translocation of 32P between distant resource units and more than 90 % of accumulated phosphorus was translocated to the inocula or to new resource units. Allocation of opportunistically-scavenged phosphorus was in preferential order of the potential of new resource units as carbon sources and in proportion to the mass of like resource units. Non-destructive 32P determination, using a scintillation probe, showed that significant differences (P 0.05) in allocation to combinations of new resource units could be detected within 12 d and corresponded with the results of destructive total 32P determination after nine weeks. The results are discussed in terms of the role of saprotrophic Cord-forming basidiomycetes in nutrient cycling and the efficiency of nutrient allocation within their Cord systems.
Damian P Donnelly - One of the best experts on this subject based on the ideXlab platform.
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Resource acquisition by the Mycelial‐Cord‐former Stropharia caerulea: effect of resource quantity and quality
FEMS Microbiology Ecology, 2006Co-Authors: Damian P Donnelly, Lynne BoddyAbstract:Saprotrophic Mycelial-Cord-forming basidiomycetes, which extend between organic substrata on the forest floor, exhibit remarkable patterns of reallocation of biomass and nutrients when encountering new resources. These have been equated with foraging strategies, and differ between species, resources quality and quantity. Stropharia caerulea occupies more disturbed sites than the fungi previously examined, and the responses of its Mycelial foraging systems were investigated non-destructively by image analysis. Resource quantity and quality affected extension rate, extra-resource biomass production and distribution, as quantified by box-count fractal dimension. When mycelia grew from 0.5 cm3 beech (Fagus sylvatica) wood inocula across compressed, non-sterile soil to 0.06–4 cm3 uncolonised sterile beech wood "baits" extension rate fell after contact with large wood baits but biomass production and Mycelial distribution was unaffected. In contrast, extension rates of Cord systems grown from 0.15 cm3U. dioica rhizome inocula to 0.1–1.2 cm3 rhizome "baits" were unaffected after contact with equal or larger sized baits, but biomass production rates fell and mass fractal dimension increased. Mycelial morphology was affected by inoculum age; systems grown from 84 day old 0.5 cm3 beech wood inocula took 10 days longer achieving the fractal values of systems developing from 22 day old inocula. Foraging strategies and resource relations of Mycelial Cord systems are discussed.
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Repeated damage results in polarised development of foraging Mycelial systems of Phanerochaete velutina
FEMS Microbiology Ecology, 1998Co-Authors: Damian P Donnelly, Lynne BoddyAbstract:Mycelial Cord systems of Phanerochaete velutina growing from wood inocula across non-sterile soil were subjected to disturbance by repeated (6–9-day intervals) complete severance and removal of Cords emerging from three, four or zero (control) vertical sides of the inoculum. Regrowth occurred after removal from four sides, though morphology, quantified by fractal dimension (DBM), did not differ from controls. After removal from three sides, Mycelial regrowth occurred and the DBM values of both intact and regrown parts of the mycelium were initially the same. Following subsequent removal, limited regrowth occurred, i.e. systems became polarised towards the intact mycelium. The proportion of regrowth from three disturbed sides altered, Mycelial area fell from 72% to 30–50% of regrowth from inocula disturbed at all four sides. The reduced regrowth also had lower DBMs than the intact mycelium developing from the undisturbed side of the inoculum. Mycelial extension rate of all regrowth from severed sides was slower than undisturbed mycelium. Decay of inocula was greater, though not significantly, where extra-resource mycelium was most extensive.
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Wood decay and phosphorus translocation by the Cord‐forming basidiomycete Phanerochaete velutina: the significance of local nutrient supply
New Phytologist, 1998Co-Authors: John M Wells, Lynne Boddy, Damian P DonnellyAbstract:Mycelial Cord systems of Phanerochaete velutina (DC.: Pers.) Parmasto grown from 4 cm3 inocula on a nutrient-depleted non-sterile soil in compartmentalized laboratory microcosms were baited after 13 d of growth with either fresh, non-sterile 4 cm3 wood blocks or control Perspex® blocks of the same contact area. After 112 d, mature Mycelial systems, which were in senescent phase, were subjected to disturbance by supplying a new fresh wood bait diametrically opposite the existing bait and, after 126 d, to nutrient regime amendment by application of NPK solution. At harvest (186 d) there was a significant (P0·001) linear relationship between extra-resource Mycelial biomass and total wood decay over the preceding 74 d. Nutrient amendment alone did not significantly (P>0·05) affect extra-resource Mycelial biomass production or wood decay rates in either disturbed or undisturbed Cord systems. However, both Mycelial biomass production and resource decay were significantly (P0·05) enhanced when nutrient amendment and disturbance treatments were applied concurrently. Bi-directional phosphorus translocation to inocula and wood baits (determined non-destructively) was assessed by labelling the NPK solution applied distal or proximal to the initially supplied bait with 32P. In both disturbed and undisturbed Cord systems the rate of 32P uptake from a local supply was two orders of magnitude higher than from a distal supply. In disturbed Cord systems uptake of 32P by inocula, which were midway between the two radiotracer supply points, was significantly (P0·05) higher when the supply point contained a newly supplied wood bait. Net translocation of 32P to newly supplied wood baits increased with time at the expense of translocation to inocula and existing wood baits. The switch in direction of net phosphorus translocation, the importance of localized nutrient scavenging and the partitioning of wood decay are discussed in relation to the ecological significance of Mycelial Cords.
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patch formation and developmental polarity in Mycelial Cord systems of phanerochaete velutina on a nutrient depleted soil
New Phytologist, 1997Co-Authors: John M Wells, Damian P Donnelly, Lynne BoddyAbstract:SUMMARY Development of Mycelial Cord systems of Phanerochaete velutina (DC.: Pers.) Parmasto from 4-cm3 inocula on a nutrient-depleted non-sterile soil was studied in laboratory microcosms using image analysis techniques. Cord systems were “baited” after 13d growth with either fresh, non-sterile 4-cm3 wood baits or control Perspex® blocks of the same contact area placed behind the foraging Mycelial front. After 26 d growth, Mycelial ‘patches’ arose by dedifferentiation of consolidated Mycelial Cords in both wood- and Perspex-baited Cord systems. ‘Patches’ comprised fine, highly branched separate hyphae extending radially from points of aggregated hyphae in Cords. ‘Patches’ and Cords could be readily distinguished by image analysis and the areas covered by patches and Cords could be measured and compared. Whilst the total hyphal cover of Perspex- and wood-baited systems did not differ significantly (P > 0.05), patch cover in wood-baited systems was up to 10 times greater than in Perspex-baited systems. Patches were temporary structures, regressing more rapidly with age than Mycelial Cords. Patch development ceased after application of a nutrient solution which replenished phosphate levels in the soil. Wood-baited Mycelial systems displayed significant developmental polarity (P≤ 005) of both total hyphal cover (patches plus Cords) and hyphae in patches towards the ‘baited’ sector of Cord systems after 42 d, which corresponded with peak patch development. However, significant (P≤ 0.05) developmental polarity of the Mycelial systems along the bait-inoculum line could be detected 8 d before patch formation when assessed by fractal geometry. Radiotracer studies showed that Mycelial patches were not sinks for supplied 32P, but that they were sites of increased nutrient uptake capacity compared with that of Mycelial Cords. We discuss the need for Mycelial Cord systems to balance allocation of Mycelial biomass between the two essential processes of colonizing wood resource units, and the acquisition of soluble inorganic nutrients from soil.
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Patch formation and developmental polarity in Mycelial Cord systems of Phanerochaete velutina on a nutrient‐depleted soil
New Phytologist, 1997Co-Authors: John M Wells, Damian P Donnelly, Lynne BoddyAbstract:SUMMARY Development of Mycelial Cord systems of Phanerochaete velutina (DC.: Pers.) Parmasto from 4-cm3 inocula on a nutrient-depleted non-sterile soil was studied in laboratory microcosms using image analysis techniques. Cord systems were “baited” after 13d growth with either fresh, non-sterile 4-cm3 wood baits or control Perspex® blocks of the same contact area placed behind the foraging Mycelial front. After 26 d growth, Mycelial ‘patches’ arose by dedifferentiation of consolidated Mycelial Cords in both wood- and Perspex-baited Cord systems. ‘Patches’ comprised fine, highly branched separate hyphae extending radially from points of aggregated hyphae in Cords. ‘Patches’ and Cords could be readily distinguished by image analysis and the areas covered by patches and Cords could be measured and compared. Whilst the total hyphal cover of Perspex- and wood-baited systems did not differ significantly (P > 0.05), patch cover in wood-baited systems was up to 10 times greater than in Perspex-baited systems. Patches were temporary structures, regressing more rapidly with age than Mycelial Cords. Patch development ceased after application of a nutrient solution which replenished phosphate levels in the soil. Wood-baited Mycelial systems displayed significant developmental polarity (P≤ 005) of both total hyphal cover (patches plus Cords) and hyphae in patches towards the ‘baited’ sector of Cord systems after 42 d, which corresponded with peak patch development. However, significant (P≤ 0.05) developmental polarity of the Mycelial systems along the bait-inoculum line could be detected 8 d before patch formation when assessed by fractal geometry. Radiotracer studies showed that Mycelial patches were not sinks for supplied 32P, but that they were sites of increased nutrient uptake capacity compared with that of Mycelial Cords. We discuss the need for Mycelial Cord systems to balance allocation of Mycelial biomass between the two essential processes of colonizing wood resource units, and the acquisition of soluble inorganic nutrients from soil.
Melanie J Harris - One of the best experts on this subject based on the ideXlab platform.
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Nutrient Movement and Mycelial Reorganization in Established Systems of Phanerochaete velutina, Following Arrival of Colonized Wood Resources
Microbial Ecology, 2005Co-Authors: Melanie J Harris, Lynne BoddyAbstract:The effect of arrival of wood resources, precolonized by Coriolus versicolor , Phlebia radiata , Stereum hirsutum , and Vuilleminia comedens , on Mycelial systems of Phanerochaete velutina was studied in trays of nonsterile soil in the laboratory over 5 months. Morphological responses were quantified nondestructively using image analysis. In a parallel series of experiments, nutrient movement was also quantified nondestructively using ^32P monitoring with a scintillation probe and subsequently by destructively harvesting after 155 days. The presence of a fungus occupying a newly arriving resource had major effects on deployment of biomass and on the uptake and allocation of phosphorus in the established Pha. velutina system. The effects varied depending on the species occupying the new resource. Hyphal coverage was greater in the half of the system to which new resources were added. Following addition of new resources, there was massive redeployment of biomass away from regions with no new resource when the new resource was (1) uncolonized, (2) colonized by V. comedens , or (3) colonized by S. hirsutum (although to a lesser extent with the latter), but not with others. ^32P was taken up by Pha. velutina both in the vicinity of the inoculum and the new resource and was translocated to the new resource from both sites of uptake; however, the local supply contributed most. Bidirectional translocation also occurred. The results are discussed in relation to Mycelial foraging strategies, nutrient translocation, and partitioning within Mycelial Cord systems.
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dynamics of Mycelial growth and phosphorus partitioning in developing Mycelial Cord systems of phanerochaete velutina dependence on carbon availability
New Phytologist, 1999Co-Authors: John M Wells, Melanie J Harris, Lynne BoddyAbstract:Mycelial Cord systems, up to 50 cm in diameter, of the basidiomycete Phanerochaete velutina, a common woodland saprotroph, were grown on unsterile soil in model laboratory microcosms from either 4 or 16 cm3 wood inocula. After 48 d, systems were supplied at 10-d intervals with pairs of new 4 cm3 beechwood resources placed behind the foraging colony margin, where possible on opposite sides of the system. Image analysis was used to quantify radial extension, hyphal cover, the mass (DBM) and surface fractal (DBS) dimensions of the Mycelial systems and wood-resource bleaching activity. Mycelial systems developing from small inocula had significantly (P0.05) lower radial extension rates, hyphal cover and DBM∶DBS ratio than those from large inocula. Initially, systems developing from small inocula also displayed significantly (P 0.05) affected by inoculum resource size. However, the proportion of total acquired P allocated to resources, which varied acCording to the length of time that resources had been in contact with the mycelium, was dependent upon inoculum size. The results support the hypothesis that phosphorus translocation is not a demand-driven process. We suggest that the time taken before the greatest rate of phosphorus withdrawal from a uniform translocation stream is dependent upon prior availability of carbon within colonized resources.
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temporary phosphorus partitioning in Mycelial systems of the Cord forming basidiomycete phanerochaete velutina
New Phytologist, 1998Co-Authors: John M Wells, Melanie J Harris, Lynne BoddyAbstract:Mycelial Cord systems, up to 50-cm diameter, of the basidiomycete Phanerochaete velutina (DC.: Pers.) Parmasto, a common woodland saprotroph, grown on non-sterile soil in model laboratory microcosms were baited, after 27 d, with pairs of fresh beech wood blocks (baits), placed at 10 d intervals behind the foraging colony margin. System development was quantified by image analysis. Mean radial extent and hyphal cover increased linearly with time until day 21, but declined before the Mycelial systems reached the edges of the laboratory microcosms. The mass (DBM) and border (DBS) fractal dimensions of the Mycelial systems changed with time but the ratio DBM∶DBS became constant after 14 d. A separate central compartment containing the inoculum was supplied with 32P orthophosphate and its translocation to wood baits monitored non-destructively for 73 d. Whilst total 32P acquisition by wood baits increased linearly with time, the proportion of total allocated to baits varied significantly both temporally and acCording to the length of time that baits had been in contact with the mycelium. Most recently supplied wood baits were not the main sink for supplied phosphorus; rather, the rate of 32P acquisition was initially greatest in baits from which egress of the fungus had already occurred. The rate of 32P acquisition by the most recently added baits increased with time, supported by efflux from other wood baits, which had initially been the main sinks for translocated phosphorus. The results raise important questions about the ecological and functional significance of nutrient partitioning in Cord systems and imply that ‘observed’ translocation, rather than being an absolute measure, indicates the degree to which phosphorus is loaded from a translocation stream in regions where it is being actively utilized and/or stored.
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Temporary phosphorus partitioning in Mycelial systems of the Cord‐forming basidiomycete Phanerochaete velutina
New Phytologist, 1998Co-Authors: John M Wells, Melanie J Harris, Lynne BoddyAbstract:Mycelial Cord systems, up to 50-cm diameter, of the basidiomycete Phanerochaete velutina (DC.: Pers.) Parmasto, a common woodland saprotroph, grown on non-sterile soil in model laboratory microcosms were baited, after 27 d, with pairs of fresh beech wood blocks (baits), placed at 10 d intervals behind the foraging colony margin. System development was quantified by image analysis. Mean radial extent and hyphal cover increased linearly with time until day 21, but declined before the Mycelial systems reached the edges of the laboratory microcosms. The mass (DBM) and border (DBS) fractal dimensions of the Mycelial systems changed with time but the ratio DBM∶DBS became constant after 14 d. A separate central compartment containing the inoculum was supplied with 32P orthophosphate and its translocation to wood baits monitored non-destructively for 73 d. Whilst total 32P acquisition by wood baits increased linearly with time, the proportion of total allocated to baits varied significantly both temporally and acCording to the length of time that baits had been in contact with the mycelium. Most recently supplied wood baits were not the main sink for supplied phosphorus; rather, the rate of 32P acquisition was initially greatest in baits from which egress of the fungus had already occurred. The rate of 32P acquisition by the most recently added baits increased with time, supported by efflux from other wood baits, which had initially been the main sinks for translocated phosphorus. The results raise important questions about the ecological and functional significance of nutrient partitioning in Cord systems and imply that ‘observed’ translocation, rather than being an absolute measure, indicates the degree to which phosphorus is loaded from a translocation stream in regions where it is being actively utilized and/or stored.
