An oligonucleotide primer set (PaF/PaR) was designed for polymerase chain reaction (PCR) amplification of an approximately 1. 2kb fragment DNA from Paulownia Witches’ broom(PaWB) MLO on the basis of 16S rRNA sequence from O-MLO. Amplification of a 1. 2kb DNA fragment from PaWB-MLO-infected plants DNA in total nucleic acid extrats of the host plant Paulownlh spp., but no l. 2kb DNA fragment was observed when healthy DNA was used as a template. The study showed that the PCR method was able todetect PaWB-MLO in as little as 9. 4pg of total DNA from infected Paulernia tissue culture plantlets.
