SPATIAL STRUCTURE OF A POPULATION OF TRICHOLOMOPSIS PLATYPHYLLA IN A WOODLAND SITE

SIMMARYA detailed in\ estimation of the liana biotype (L-biot\ pe) of Crinipellis perniciosa (Stahel) Sing, was conducted in Ecuador. Basidi()carps of the L-hiotype were consistenth found in association with stems or debris of the liana Arrabidciea verrucosa (Standl) A. Gt-ntry, although no symptoms associated with witches' broom disease were observed. Debris colonized by the L-bioT\ pe were often connected via pseudosclerotial pads to living stems of A. verrucosa. Pairings between 87 isolates obtained from biasidiocarp stipe tissues or liana bark cores from three sites permitted 37 somatic compatibility groupings (SCGs) to be detined. In all cases these were found to be very restricted in geographical distribution, a situation which contrasts markedly with the distribution of SCfis in the pathogenic and non-outcrossing cocoa biotype. Mating pairings between single basidiospore isolate.s confirmed that the outcrossing mechanism of the L-biotype is mukiallelic and that no signiticant biological barriers to gene flow exist between coastal and Amazonian populations. Se\'eral lines of evidence suggested that mycelia belonging to the same SCG (= genet) were isogenic. Correlations between field observations and the distributions of both SCGs and mating type factors are discussed in relation to patterns of dispersal, establishment and spread oi this fungus.

Section: Discussionmentioning

confidence: 99%

Spatial distribution of mycelia of the liana (L‐) biotype of the agaric Crinipellis perniciosa (Stahel) Singer in tropical forest

Griffith

Hedger

1994

“…Physical factors, such as temperature and humidity would have been less subject to the fluctuations characteristic of the subaerial environment and partly in consequence the type of inoculum, its density, ecological activity and species diversity would have been different. Studies by Carruthers & Rayner (1979), Thompson & Rayner (1982a, b, 1983, Thompson & Boddy (1983) and Thompson (1984) have all shown that rhizomorph-and mycelial cord-forming basidiomycetes are major agents of wooddecay on the deciduous woodland floor where their extensive mycelial systems provide them with a positional advantage and high inoculum potential {sensu Garrett, 1970), facilitating rapid establishment in newly available substrata. This has been substantiated by the present study in which rapid arrival, absence or scarcity of somatic incompatibility within logs or between isolates from different logs, and clustering of logs colonized by the same species (Fig.…”

Section: Discussionmentioning

confidence: 99%

Fungal Population and Community Development in Cut Beech Logs

Coates

Rayner

1985

Self Cite

SUMMARYPatterns of fungal colonization from the base of cut beech logs placed upright and partly buried in the ground at a mixed deciduous woodland site were fundamentally different from those from the aerial cut surface.Principal colonists resulting in decay, and mostly arriving within three months, were the ascomycete Xylaria hypoxylon (L. ex Hooker) Greville and various rhizomorph/mycelial cord-forming basidiomycetes, including Armillaria hulbosa (Barla) Kile & Watling, Phallus impudicus (L.) Pers., Phanerochaete velutina (DC ex Pers.) Parmasto and Tricholomopsis platyphyll^ (Pers. ex Fr.) Sing. Apart from A. bulbosa, these generally readily formed mycelial mats on the basal surface, between which somatic incompatibility reactions were often observed. Most frequent reactions occurred with X. hypoxylon which almost invariably produced numerous individuals in discrete decay columns. By contrast, lack of somatic incompatibility reactions between isolates of ^. bulbosa indicated that a single extensive mycelial type occurred throughout the site. The occurrence of somatic incompatibility between isolates of P. velutina from different logs indicated independent establishment, presumably via basidiospores, and this was consistent with the unusually late arrival of this species at the site. In no cases were numerous somatically incompatible individuals isolated from small volumes of wood lacking demarcation into discrete columns, as had been observed near the aerial cut surface.Vertical penetration from the base was more rapid than from the aerial cut surface, with X. hypoxylon a major pioneer species, and there was no pronounced lag phase.

“…Fragmentation is a common feature in clonal plants (Harper, 1977). Several examples of filamentous fungi suggest that fragmentation might also be a frequent phenomenon in fungi in their natural environments (Thompson & Rayner, 1980 ;Holmer & Stenlid, 1991 ;Dahlberg & Stenlid, 1994 ;Rizzo et al, 1995). The likelihood of fragmentation increases with age of fungal genet.…”

Section: mentioning

confidence: 99%

Spatial distribution of discrete RAPD phenotypes of a root endophytic fungus, Phialocephala fortinii, at a primary successional site on a glacier forefront

Jumpponen

1999

Phialocephala fortinii is among the few identified hyphomycetes belonging to the Mycelium radicis atrovirens complex. This ' dark-septate endophyte ' has a global distribution and colonizes a wide variety of host plants. In this study, the spatial distribution of discrete genets of P. fortinii on the forefront of a receding glacier was analysed using the randomly amplified polymorphic DNA (RAPD) technique to determine plants colonized and patterns of colonization. In two consecutive years of sampling, a total of 74 isolates of P. fortinii were obtained from nine plant species, typically ectomycorrhizal, ericoid mycorrhizal or non-mycorrhizal. The isolates showed substantial variation, sharing on average approx. half the RAPD markers. In the first year, three isolates belonging to a single genet were obtained from two plants separated by a distance of nearly 1n5 m. The continuity of this genet was assessed by a sampling the following year. No isolates similar to that, or any of the genets collected the year before were observed. Consequently, the identical isolates from the previous year were concluded to represent discontinuous ramets. Two additional large genets were observed during the second year of sampling, which inhabited roots of several plants representing three different species. These data suggest that the sharing of P. fortinii genets among plant species might play a fundamental role in adaptation and interaction within the whole plant community in a system undergoing primary succession.