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Roots of ten species of Lupinus and three other legumes collected from field soils were cleared, stained, and examined for fungal colonization. Three species were not colonized. Nine species were colonized by aseptate hyphae and vesicles attributable to vesicular-arbuscular mycorrhizal fungi. Seven species were sometimes colonized by fungi with septate hyphae, which often formed intracellular sclerotia. The associations observed are compared with previous reports and discussed in relation to legume systematics. [ABSTRACT FROM AUTHOR]

Root colonization patterns were studied after Phialocephala fortinii was inoculated on Lupinus latifolius (broad-leafed lupin), a nitrogen-fixing legume, and Pinus contorta (lodgepole pine). The fungus colonized epidermal and cortical cells in the root hair zone on ultimate pine roots, as well as cortical and epidermal cells of primary roots of both hosts. Fungal colonization was inter- and intracellular with sclerotia forming in cells of both hosts. Labyrinthine tissue, a type of fungal differentiation that occurs in the Hartig net of ectomycorrhizas, formed sporadically on pine roots Similar colonization has been observed on conifers and many other plants, but this report is the first showing that a single fungus can form such structures on both pine and lupin. [ABSTRACT FROM AUTHOR]

summary To test the effect of ectomycorrhizal fungi (EMF) on interactions between host plants, Pseudotsuga menziesii (Mirb.) Franco and Pinus ponderosa Dougl. ex. Laws., seedlings were grown in replacement series in pasteurized soil with (a) no EMF added, (A) two EMF species added - Rhizopogon vinicolor Smith (specific to Douglas-fir) and R. ochraceorubens Smith (specific to pine), and (c) tour EMF species added - the two Rhizopogon species plus two host generalists, Laccaria laccata (Scop, ex Fr.) Bk. & Br, and Hebeloma crustuliniforme (Bull.) Quel. A replacement series in unpasteurized forest soil also was included. Seedlings without added EMF were colonized by the greenhouse contaminant, Thelephora terrestris. Without added EMF (but with T. terrestris), the tree species mutually inhibited one another, producing Relative Yield Totals significantly < 1; with EMF added, mutual inhibition disappeared. With four EMF species added, Pseudotsuga menziesii seedlings were significantly larger in mixture than in monoculture, with no corresponding decrease in the size of Pinus ponderoso seedlings; this was due solely to seedlings with L. laccata, which apparently enhanced nitrogen (N) and phosphorus (P) uptake by Pseudotsuga menziesii at the expense of luxury consumption by Pinus ponderosa. Graphical analysis suggested that better growth of Pseudotosuga menziesii in mixture with EMF added was related to improved P nitrogen. Both N and P nutrition of Pinus ponderosa was better in mixture with two than no EMF species added; there was no clear nutrient effect with four EMF species added. Results indicate that EMF can reduce competition between plant species and perhaps increase overall community P uptake. However, patterns were specific to both EMF and tree species and were quite different in unpasteurized soils. Hence generalizations about the effects of EMF on plant-plant interactions must be made cautiously. [ABSTRACT FROM AUTHOR]

Examines the interrelationship among ectomycorrhial trees, hypogeous fungi and small mammals. Classification of small mammals as important vectors of spores of hypogeous fungi; Establishment of pure culture synthesis of mycorrhizae; Assessment of factors affecting the development of abundant ectomycorrhizae.