Detection of Bacterial Ring Rot of Potato Using Dna Probe and PCR

Abstract

<jats:p>One hundred twenty-eight field samples of 25 potato stem sections were analyzed for detecting bacterial ring rot (BRR). Samples containing more than 10<jats:sup>5</jats:sup>, between 10<jats:sup>5</jats:sup> and 10<jats:sup>4</jats:sup>, and &lt;10<jats:sup>4</jats:sup> immunofluorescing BRR cells per milliliter of sample, detected using immunofluorescence-antibody staining with MAb9A1, were used to compare the efficiency of two other detection methods. Samples were screened with a digoxigenin-labeled DNA probe (Bh1 2, 0.6 kbp) detected by chemioluminescence on nylon membrane. Samples also were screened with a PCR test using primers derived from the sequence of the Bh12 probe. DNA probe tests on these three bacterial concentrations showed a detection efficiency of 100%, 76.8%, and 8.0%, respectively, whereas detection efficiencies of 100%, 100%, and 84.5% were obtained with PCR tests. Almost all positive samples gave the expected 403 bases ethidium-bromide-stained band when the amplified products were analyzed on 1.4% agarose gel. Thus, the PCR test was a sensitive detection method for screening bacterial ring rot of potato.</jats:p>