Interactions between Rhizoctonia tuliparum and soil microorganisms.

Gladders, P.; Coley-smith, J. R.

ABSTRACT Rhizoctonia tuliparum Whetzel & Arthur is a winter active soil-borne pathogen, which causes the grey bulb rot of tulips and Dutch irises. The fungus survives by means of sclerotia. It was found that the sclerotia only germinated in unsterile soil at low temperatures (0-10 °C). Germination in sterile soil occurred over a wider range of temperatures (0-25 °C) but was inhibited at 20 °C after the addition of a suitable bacterial inoculum. An unidentified pyrone antibiotic was leaked by sclerotia which had been air-dried and re-wetted. This could be detected in vitro using an agar medium seeded with a spore suspension of Bacillus subtilis Cohn emend Prazmowski. In soil, however, material leaked by sclerotia stimulated both bacteria and fungi. Undried, air-dried and oven-dried (non antibiotic) sclerotia persisted equally well in soil over 2 yr. This suggests that the resistance to lysis of sclerotial cell walls may be important in the long term survival of this organism.

Annals of Applied Biology, 1978, Vol 89, Issue 1, p131

0003-4746

Academic Journal

10.1111/j.1744-7348.1978.tb02588.x