In vitro observations of net community production (NCP) imply that the oligotrophic subtropical gyres of the open ocean are net heterotrophic; in situ observations, in contrast, consistently imply that they are net autotrophic. At least one approach must be returning an incorrect answer. We find that (a) no bias in in situ oxygen-based production estimates would give false-positive (net autotro...

An autotrophic culture system was developed for the in vitro mycorrhization of potato plantlets. Roots of micropropagated plantlets were associated to an arbuscular mycorrhizal fungus under in vitro conditions, while shoots developed under open air conditions. Several thousand spores, an extensive extraradical mycelium and an abundant root colonization were obtained. Spores were able to coloniz...

In chlorophyll-containing spores of Onoclea sensibilis, depletion of lipid reserves during germination is correlated with increases in the activity of the glyoxylate cycle enzymes isocitrate lyase and malate synthase. In Onoclea, the heterotrophic activity associated with lipid catabolism occurs at the same time that autotrophic activity is taking place. Increases in chlorophyll content and in ...