Abstract: Fastidious prokaryotes limited in vascular bundle of several yellow diseased plants were successfully recovered by means of vacuum extraction and alternative centrifugation. Fastidious bacteria were obtained from apple scar peel disease, pear scar peel disease and persimon proliferation disease. MLO associated with paulownia witches' broom disease was also recovered by this method. Electron micrographs showed the noticeable feature of these prokaryotes.The fastidious bacteria are rod-shaped cell, 0.5—1.0×1.0—3.0μm, with rippled cell walls. The globular wall-less cells with a single unit membrane were observed in the case of paulownia witches' broom.The fastidious bacteria extracted from apple scar peel disease were used as antigen to immunize rabbits. The antiserum obtained reacts obviously with the bacteria recovered from apple and pear plants with scar peel disease. It does not show any visible reaction with the corresponding samples made from healthy plants.

Key words: Vacuum extraction, MLO, Fastidious bacteria