Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/1997
Publication Date: N/A
Technical Abstract: Identification of D. bryoniae, the causal agent of gummy stem blight (GSB), involves isolation of the fungus and examination of its morphological an cultural characteristics. Frequently, nonpathogenic Phoma spp. are simultaneously isolated from cucurbits with GSB symptoms. Random amplified polymorphic DNA (RAPD) analysis of 61 GSB isolates from SC, NY, NC, FL, AZ and WI distinguished between D. bryoniae and Phoma isolates and a separate group putatively identified as a second Phoma group. Unique RAPD fragments from each group were identified by differential hybridization of PCR products and sequenced to generate PCR primers. Specific primer pairs amplified a unique DNA fragment for each group of isolates. This allows identification and differentiation between D. bryoniae and Phoma isolates and in the future will aid in accurate diagnosis of GSB. Colorimeric detection of amplification products is being developed for simple and effective visualization of PCR products.