A direct observation technique for studies on rhizoplane and rhizosphere colonization

Summary A slide incubation chamber was described which allowed small plants to be grown from seed and the root systems to be observed microscopically. A fluorescence stain, the ammonium salt of 8-anilino-1-naphthalene sulfonic acid, was applied to the soil in which the roots were growing and the stained microorganisms on the roots and in the rhizosphere were counted. A statistical pattern analysis technique, the two-within-four randomization test, was used to analyze the data obtained from quadrats on the roots. Distinct colonization patterns and colony growth, especially of bacteria, were easily distinguished with the technique.