Distribution and persistence of Australian Pisolithus species genets at native sclerophyll forest field sites

Basidiomes of a Pisolithus species were collected from a ca 2500 m(2) Austr alian sclerophyll forest site during 1997 and 1999 and of a second Pisolith us species from a further ca 150 m(2) site during 1999. Inter-simple sequen ce repeat (ISSR) FCR was conducted on DNA extracted from each basidiome usi ng the primers 5 ' BDB(ACA)(5), 5 ' DDB(CCA)(5) and 5 ' DHB(CGA)(5). Thirty -seven genotypes of Pisolithus species I were detected at the North Wilberf orce site, with eight genotypes present during both 1997 and 1999. All othe r genotypes were observed during only one year. Mapping genotype distributi on according to location of basidiome collection at the site suggested that most genotypes were present as small (< 2.0 m(2)) below-ground mycelial ge nets, however several larger (> 4.0 m(2)) genets (including one ca 120 m(2) genet) were also present. All Pisolithus species II basidiomes at the Nort h Turramurra site were of a common genotype, suggesting the presence of a s ingle large (ca 69 m(2)) below-ground mycelial genet of this taxon at the s ite. Both Pisolithus species thus appear to produce large long-lived soil-b orne mycelia, but establishment of large genets may be restricted under som e circumstances.