ROOT COLONIZATION OF LUPINUS-LATIFOLIUS AGARDH AND PINUS-CONTORTA DOUGL BY PHIALOCEPHALA-FORTINII WANG AND WILCOX

Root colonization patterns were studied after Phialocephala fortinii w as inoculated on Lupinus latifolius (broad-leafed lupin), a nitrogen-f ixing legume, and Pinus contorta (lodgepole pine). The fungus colonize d epidermal and cortical cells in the root hair zone on ultimate pine roots, as well as cortical and epidermal cells of primary roots of bot h hosts. Fungal colonization was inter- and intracellular with sclerot ia forming in cells of both hosts. Labyrinthine tissue, a type of fung al differentiation that occurs in the Hartig net of ectomycorrhizas, f ormed sporadically on pine roots. Similar colonization has been observ ed on conifers and many other plants, but this report is the first sho wing that a single fungus can form such structures on both pine and lu pin.