| Abstract: | Partially purified mycoplasma-like organism (MLO) preparations were obtained from diseased paulownia with witches' broom (PWB). EcoR Ⅰ -Hind Ⅲ digested fragment of the total DNAs extracted from the preparations was Iigated into pGEM-3Zf (+) vector. The recombinant molecules were transformed into Escherichia coli strain DH5α. After screening by differential hybridization and identification with Dot and Southern blot hybridization analysis, two clones (A4, 1.69 kb and C42, 2.08 kb) were obtained. Their DNA inserts as probes hybridized only with total DNAs from PWB-diseased plants but not with extracts from healthy plants. Abundant (A+T) content was found in the sequences of DNA inserts from the two clones, 72.5% (A4) and 67.9% (C42, respectively, which possessed the character of DNA from mycoplasma spp. |
