Dr. J.R. Steadman lab

Epidemiology and Plant Disease Resistance

Pathogens of interest 
Sclerotinia sp.
-causal agent of White Mold Disease
in beans, soybeans and other crops
Uromyces appendiculatus
-causal agent of Bean Rust
Rhizoctonia solani

-causal agent of Web Blight
 in beans


  • Genetic diversity of Rhizoctonia solani isolates and development of a differential set of bean lines to screen for web blight resistance
  • Screening of bean germplasm for resistance to white mold, and identifing genetic diversity in Sclerotinia isolates
  • Identification of disease resistance in a wild x domesticated cross of beans, and identifing molecular markers for marker-assisted selection 
  • Characterization, by traditional and molecular means, of web blight of dry beans, and identification and characterization of begomovirus and potyvirus associated to legumes in the Caribbean region.
  • Collaborations

    South Africa
    Dominican Republic/Haiti
    Puerto Rico


    USDA - Multistate (W-150)
    USDA- Sclerotinia Initiative
    USDA Plant Exploration/ Germplasm evaluation
    Bean Industry- NE Drybean Commission

    Recent Posters
    (PDF format)
    Multi-site Screening for Sclerotinia sclerotiorum: A Successful Approach...
    JR Steadman, 14th Int'l Sclerotinia Workshop, 2009

    New Subgroups of Rhizoctonia solani that cause web blight of common bean identified by sequence analysis of the ITS rDNA region.
    G. Godoy-Lutz, APS 2006
    Origin of Virulence Diversity in Plant Pathogen Populations: Bean Rust as a Case Study
    M. Acevedo, APS 2004
    Pathogenic Variability of Populations of the Bean Rust Pathogen, Uromyces appendiculatus, in Individual Bean Fields
    C. Jochua, South Africa Legume Conference, 2005
    Comparison of Measurement Methods Using the Sensitivity Ratio: An Application to Screening for Disease Resistance in Soybeans.
    G. Madisa, APS 2004
    Pathogen Phenotypes used to Identify Sources of Resistance to Rust from a Specific Common Bean Gene Pool in Southern Mozambique
    C. Jochua, APS 2004
    Host-pathogen interaction in wild populations:
    a tool for effective use of resistance genes
    M. Acevedo, 2005
    Ribosomal intron distribution and species discrimination in spp. Sclerotinia
    K. Powers

    Sclerotinia Resistance Enhanced by Transgenic Approaches
    G. Graef