Molecular diversity of ericoid mycorrhizal endophytes isolated from Woollsia pungens

Abstract

One hundred and sixty-eight sterile endophytic mycelia were isolated from roots of four Woollsia pungens (Cav.) F. Muell. (Epacridaceae) plants collected from a field site in New South Wales, Australia. All isolates formed typical ericoid mycorrhizal structures when inoculated onto roots of Vaccinium macrocarpon Ait. (Ericaceae). Microsatellite-primed PCR fingerprints generated using the primers (GTG) & and (GACA) % indicated that considerable genetic diversity exists within the endophyte population. It was estimated that a minimum of 43 genetically distinct mycelial genets were present in the root systems of the sampled W. pungens population, with most genets confined to individual plants. Two genets, however, were present within the root systems of two adjacent plants. While most genets were represented by less than eight isolates, three genets contained up to 41 isolates, suggesting that root system colonization by some endophytic mycelia might be extensive.

Genetic diversity of root‐associated fungal endophytes from Calluna vulgaris at contrasting field sites

“…While the taxonomic status of ericoid mycorrhizal endophytes of Ericales hosts has received some attention, far less effort has been focused on determining the diversity of endophyte assemblages present within root systems of a host taxon at a single field site or of the same taxon at different field sites. Results of several studies indicate that a single stand of an Ericales host species might be colonized by several endophyte taxa, as can the root system of an individual plant within such a stand (Perotto et al, 1990(Perotto et al, , 1995Xiao & Berch, 1996 ;Hambleton & Currah, 1997 ;Liu et al, 1998 ;Chambers et al, 2000). Although detailed functional studies have yet to be performed on endophytes other than H. ericae, it seems likely that such diversity might be of considerable functional significance to the hosts (Smith & Read, 1997).…”

“…Further evidence is provided by the fact that endophytes isolated from Epacridaceae can form morphologically typical mycorrhizal associations with Ericaceae hosts (Reed, 1989(Reed, , 1996Liu et al, 1998). Only an Oidiodendron species (probably O. maius Barron) has been identified as an endophyte of an Epacridaceae host in the field and molecular data suggest that, in common with those from Ericaceae, most endophytes probably have affinities with Leotiales (McLean et al, 1999 ;Chambers et al, 2000).…”

“…might form mycorrhizas with C. vulgaris, but not with V. macrocarpon). In the light of the demonstrated inter-compatibilities between mycorrhizal endophytes from Ericaceae and Epacridaceae (Reed, 1989(Reed, , 1996Liu et al, 1998 ;McLean et al, 1999), the latter appears unlikely. It is of further interest that almost 25% of the endophytes for which RFLP patterns were consistent with H. ericae failed to form recognizable mycorrhizal structures in roots of V. macrocarpon.…”

Molecular diversity within and between ericoid endophytes from the Ericaceae and Epacridaceae

“…However, most have not been confirmed as mycorrhizal on Epacridaceae, although a few have formed ericoid mycorrhizal pelotons on Ericaceae (Reed, 1989 ;Liu et al, 1998). The recent confirmation of some Victorian epacrid isolates as being capable of forming morphologically typical ericoid mycorrhiza in Epacridaceae (McLean et al, 1998) now enables them to be compared by modern molecular methods with some known mycorrhizal fungi of the Ericaceae.…”

“…mycorrhizal endophytes of the Ericaeae produced morphologically typical ericoid mycorrhizal morphology with axenic Epacris impressa Labill. (Epacridaceae) (McLean et al, 1998) and by earlier reports of infection of Vaccinium species (Ericaceae) by fungi isolated from epacrid roots (Reed, 1989 ;Liu et al, 1998).…”