Diversity of exotic ectomycorrhizal Rhizopogon from pine plantations in Patagonia

Abstract

We present an account of Rhizopogon introduced from plantings of exotic pine plantations in Argentine Patagonia. Nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) and nuc 28S rDNA (28S) sequences were used to identify specimens from Argentina and examine their relationships with geographically different Rhizopogon species. Based on phylogenetic analyses, we confirm that four species of Rhizopogon occur in pine plantations across Patagonia. Several Rhizopogon collections from Pinus ponderosa plantations across different provinces cluster with R. arctostaphyli, a species within R. subg. Amylopogon. The majority of Patagonian Rhizopogon, however, form three different lineages in R. subg. Roseoli. The first of these, R. roseolus sensu Trappe, includes numerous collections from Pinus ponderosa, P. contorta, and P. radiata stands of North American affiliation. The second, R. roseolus sensu Martin and Garcia from P. ponderosa plantations, clusters in clade IIIa of the R. roseolus complex, which also includes the holotype collection of R. mohelnensis from the Czech Republic. The third species in R. subg. Roseoli, and fourth species overall from Patagonia, is R. granuloflavus from Pinus ponderosa plantations. Multiplex polymerase chain reaction (PCR) of numerous Roseoli samples failed to produce an amplicon indicative of either Japanese or New Zealand shoro.