Development of vesicular-arbuscular mycorrhiza in groundnut and other hosts

Summary A vesicular-arbuscular mycorrhizal fungus, identified asGlomus mosseae Gerdemann and Trappe, was found to occur in groundnut and some other hosts. In groundnut roots under experimental conditions, the fungus showed three phases of development-a lag phase of 3–4 weeks by the end of which formation of vesicles was noticed, a phase of gradual development upto 12 weeks, by which time an average of 6 vesicles per centimeter of root developed and a constant phase where there was no further increase of the fungus. Pigeon-pea, black gram, green gram, angular gourd, onion, maize, sorghum and pearl millet also formed mycorrhizae with this fungus, but tomato and egg-plant did not. The lag phase was longer and the average number of vesicles developed per unit root length was less in the non-leguminous hosts.