A Simple DNA Extraction Method for PCR-based Detection of Xanthomonas campestris pv. pelargonii in Geraniums

A simple method for PCR-based plant clinical diagnosis of bacterial blight of geraniums caused by Xanthomonas campestris pv. pelargonii is described. The method entails maceration of infected tissues in water or 10 mM Tris- HCl, pH 8.0 buffer, followed by treatment ofthe macerate with a commercially-available extraction matrix (GeneReleaser^") in which nucleic acid is released by brief microwave beating. Nucleic acid prepared in this manner served directly as template for PCR amplification with primers targeting a sequence in the genome of the bacterium. Using this protocol, it was possible to quickly identify X. campestris pv. pelargonii in infected geraniums, whereas amplification products were rrot obtained with nucleic acid preparations from noninfected plants, or from plants infected with the bacterial pathogens, Corynebacterium fascians or Pseudomonas cichorii