ARS | Publication request: GENETIC DIVERSITY AND MOLECULAR DETECTION OF RHIZOCTONIA IN NURSERY ENVIRONMENTS

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 7, 2004
Publication Date: October 7, 2004
Citation: Rinehart, T.A., Copes, W.E. 2004. Genetic diversity and molecular detection of rhizoctonia in nursery environments. Meeting Abstract.

Technical Abstract: Rhizoctonia species are soil-borne fungi that infect numerous plant species. Under hot, humid conditions Rhizoctonia can cause an aerial blight called "web blight". The fungus can be seen on blighted plant parts as fine, tan webbing that sticks to leaves and stems and grows across the soil surface. Soil-borne pathogens such as Rhizoctonia can escape notice, be distributed throughout the nursery in infested soil or through movement of diseased plants, and cause serious losses before it is identified. Prevention, in the form of good sanitation practices, is the key to controlling Rhizoctonia diseases because it can persist in soil for years. The versatile nature of Rhizoctonia comes from its broad genetic diversity. In this paper we identify the major and minor Rhizoctonia isolates infecting plants in nursery environments and characterize their growth and pathogenicity. When compared to hundreds of previously analyzed isolates, genetic data indicate a novel binucleate strain is responsible for damage to container-pad grown azaleas. This research makes possible the development of a specific, DNA-based assay to detect this new strain in soils and on surfaces. We plan to use this assay to identify inoculum sources, monitor spread, and improve sanitation practices to reduce damage.