Project Number: 1230-22000-029-00
Project Type: Appropriated

Start Date: May 20, 2008
End Date: May 19, 2013

Objective:
Develop molecular tools to detect, identify, characterize, and counteract the pathogenicity of soilborne pathogens, such as Rhizoctonia solani in ornamental crops and turfgrasses. Examine episomal and chromosomal genetic elements affecting biology or virulence of R. solani. Analyze gene expression of important soilborne pathogens, such as R. solani, to understand the virulence of the organism. Evaluate transgenic plants, including ornamentals for resistance to fungal pathogens. Improve the efficacy and consistency of biological control agents for important soilborne pathogens (Rhizoctonia, Fusarium and Ralstonia) through combination with organic amendments, new and safer chemicals, composts, and reduced-risk fungicide(s). Screen plant extracts and reduced-risk chemicals with broad spectrum properties against soilborne pathogens. Study structure/activity relationships of potential reduced-risk chemicals from plant extracts for understanding biocidal effects on R. solani or other pathogens. Investigate the combined effectiveness of bio-fumigation and/or soil-treatment with botanical extracts, antagonistic microbe(s), reduced-risk chemicals, or compost made from pine needles to control soilborne pathogens.

Approach:
Utilize molecular approaches such as UP-PCR, rDNA sequencing, etc. to distinguish pathogenic Rhizoctonia isolates and to group them. Construct expressed gene cDNA libraries of virulent and hypovirulent Rhizoctonia isolates, and analyze to identify differentially expressed genes. Develop transformation system for R. solani. Evaluate transgenic gladiolus for resistance against Fusarium oxysporum, fsp gladioli. Screen to identify plant extracts inhibitory to R. solani and other soilborne plant pathogens. Evaluate antagonistic fungi, bacteria, or other microbes to check their effectiveness alone or in combination with biorationals or soil amendments in controlling soilborne pathogens of ornamental crops.