Endogone Spores in Cultivated Soils

Abstract

USING nematological methods of wet sieving and decanting with agricultural soils in Illinois, Gerdemann^1,2 extracted two types of large one-celled spores which gave endotrophic mycorrhiza of the phycornycetous type in inoculated plants. The larger of these spores, 183–812µ diam., produced arbuscules but not vesicles in infected roots. Clusters of echinulate one-celled spores were formed on external hyphæ¹. A smaller spore, 133–288µ diam., induced typical vesicular-arbuscular infections and, in addition, produced on hyphæ surrounding the roots an Endogone sporocarpic stage and chlamydospores². The chlamydospores were identical with those extracted from field soil and the sporocarps were similar to those produced by the unnamed mycorrhizal species of Endogone described by Mosse³.