Mycelial growth characteristics in a split-plate culture of four strains of the genus <Emphasis Type="Italic">Suillus</Emphasis>

A split-plate method with two media in different concentrations in each compartment was applied for the mycelial growth of four strains of Suillus luteus, S. grevillei, S. granulatus, and S. bovinus. As the glucose concentration in the A-side (the side containing higher concentrations of glucose) increased, the mycelial growth in both A- and B-sides (the side containing lower concentrations of glucose) increased. The mycelial density in both sides and B/A ratio (the ratio of the mycelial growth in the B-side to that in the A-side) also increased, and the colony morphology changed. In both A- and B-sides, the colony area reached maximum at 10g/l glucose in the A-side in most cases and at 33.3g/l in several cases. The results indicated nutrients are translocated from mycelia in the A-side to those in the B-side. High concentration of phosphate or fructose + glucose in the A-side induced better mycelial growth in the B-side. Addition of high concentrations of phosphate to one side enhanced mycelial growth in the other side. Low-temperature incubation promoted the growth in the B-side. Our split-plate culture method will be useful for qualitative study of translocation in ectomycorrhizal fungi.