Spatial distribution and temporal persistence of discrete genotypes of the ectomycorrhizal fungus Laccaria bicolor (Maire) Orton

Abstract

SUMMARYA field study was conducted to determine the spatial distribution and temporal persistence of Laccaria bicolor (Maire) Ortori genotypes associated vvuli nafuralh tolotiizcd Norway spruce [Ficea abies (L,) Karst,] in a plantation. Groups of sporophores around three trees were mapped and collected over two to four consecutive autumn seasons to isolate cultures and determine their genetic relatedness by mating t\pe and randomly amplified polymorphic DN.^ (RAPD) analysis. Annual sporophore distribution varied significantly on all sites, with an increase in the mean radial distance from the trees over the study period. Sporophore distribution was discontinuous and characterized by clumped groupings around trees. Sporophores with the same mating type and disparate distributions were present on each of tw o sites during the sample period. RAPD analysis for each of the SIS randotn primers detected ihe same DNA polymorphisms for all dikaryolic isolates tested from a gi\ en site over the sample period. These results provide evidence that a single genetic individual of L. bicolor can remain associated with a host root system for at least 3 yr and vary significantly in its spatial distribution. This is the first instance in which the persistence of specific genotypes ol" an early-stage ectomycorrhizal fungus has been demonstrated for a tree colonized by natural sources of inoculum. The impltcations of these findings are discussed in relation to the ecology and succession of ectomycorrhizal fungi.

Tuber melanosporum: mating type distribution in a natural plantation and dynamics of strains of different mating types on the roots of nursery‐inoculated host plants

“…Embracing this thesis, it can be pointed out that seven genets were present within the Borgo Cerreto ground. Molecular markers have previously been used to identify genets of many ectomycorrhizal fungi using the allelic configuration of sporocarps, ECMs or both (Bastide et al, 1994;Anderson et al, 1998;Gherbi et al, 1999;Sawyer et al, 1999;Selosse et al, 1999;Guidot et al, 2001;Redecker et al, 2001;Kretzer et al, 2003). By examining the distribution pattern of T. melanosporum genets in Borgo Cerreto, it appears that single genets are confined to a small number of host plants.…”

“…Embracing this thesis, it can be pointed out that seven genets were present within the Borgo Cerreto ground. Molecular markers have previously been used to identify genets of many ectomycorrhizal fungi using the allelic configuration of sporocarps, ECMs or both (Bastide et al. , 1994; Anderson et al.…”

Genet distribution of sporocarps and ectomycorrhizas of Suillus pictus in a Japanese white pine plantation

“…The estimation of mycelial growth rate of ECM fungi under natural conditions varies greatly among ECM species. The value of 0.1-0.2 m yr −1 has been estimated (Ogawa, 1975;Last et al, 1983;Dahlberg & Stenlid, 1990;Bastide et al, 1994) based on the outward growth of fairly ring or the genet expansion of sporocarps, while Gryta et al (2000) reported that the two genet of H. cylindrosporum extended at a rate of c. 0.45 -0.6 m yr −1 . Bonello et al (1998) estimated mycelial growth rate of S. pungens to be 0.5 m yr −1 and Selosse et al (1999) estimated 1.1 m yr −1 for Laccaria bicolor.…”

“…Somatic incompatibility has been used to identify genets of sporocarps of several ECM fungi (Fries, 1987;Dahlberg & Stenlid, 1990Baar et al ., 1994;Dahlberg, 1997). Somatic incompatibility, however, sometimes failed to identify genets in Suillus granulatus ( Jacobson et al ., 1993) and molecular markers have been applied to identify genets of ECM fungi in recent studies ( Bastide et al ., 1994;Gherbi et al ., 1999;Sawyer et al ., 1999;Gryta et al ., 2000;Guidot et al ., 2001). Based on the analysis of the genet structure of sporocarps, these studies have proved that early stage fungi such as Hebeloma and Laccaria formed many small genets and late stage fungi such as Cortinarius formed a few large genets.…”

Recent advances in population genetics of ectomycorrhizal mushroomsRussulaspp.

“…One of the most popular hypotheses divided the lifestyles of EMF into “early-stage fungi” and “late-stage fungi.” “Early-stage” EMF are considered as pioneer colonists in early successional forest. Typical ecological characteristics for an early-stage EMF or EMF communities include a high number of genotypes, small and short-lived genets, low-level of required nutrient, and the release and dispersal of meiotic spores (De La Bastide et al 1994; Muller et al 2004). On the other hand, “late-stage” EMF are known to have large and long-lived genets with high level of nutrient requirement and mycelia expansion to spread in mature and undisturbed forests.…”