Vesicular-arbuscular mycorrhizal infections in root organ cultures

Vesicular-arbuscular mycorrhizal infections, similar to those formed in plants with leaves, have been established for the first time in clover root organ cultures. These infections are most easily established in roots grown on a modified White's agar medium but they can also form in liquid culture. The pH of the medium is a critical factor determining the initiation and spread of infection. White's medium inhibited spore germination and growing roots did not relieve this inhibition. Pre-germinated spores were therefore used as inoculum. The possible value of root organ cultures for the study of root: endophyte interactions is discussed in relation to studies of some obligate fungi.