Diversity of exotic ectomycorrhizal <i>Rhizopogon</i> from pine plantations in Patagonia

We present an account of <i>Rhizopogon</i> 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 <i>Rhizopogon</i> species. Based on phylogenetic analyses, we confirm that four species of <i>Rhizopogon</i> occur in pine plantations across Patagonia. Several <i>Rhizopogon</i> collections from <i>Pinus ponderosa</i> plantations across different provinces cluster with <i>R. arctostaphyli</i>, a species within <i>R</i>. subg. <i>Amylopogon</i>. The majority of Patagonian <i>Rhizopogon</i>, however, form three different lineages in <i>R</i>. subg. <i>Roseoli</i>. The first of these, <i>R. roseolus</i> sensu Trappe, includes numerous collections from <i>Pinus ponderosa, P. contorta</i>, and <i>P. radiata</i> stands of North American affiliation. The second, <i>R. roseolus</i> sensu Martin and Garcia from <i>P. ponderosa</i> plantations, clusters in clade IIIa of the <i>R. roseolus</i> complex, which also includes the holotype collection of <i>R. mohelnensis</i> from the Czech Republic. The third species in <i>R</i>. subg. <i>Roseoli</i>, and fourth species overall from Patagonia, is <i>R. granuloflavus</i> from <i>Pinus ponderosa</i> plantations. Multiplex polymerase chain reaction (PCR) of numerous <i>Roseoli</i> samples failed to produce an amplicon indicative of either Japanese or New Zealand shoro.