Early phases of degeneration of mycoplasma-like bodies in plant tissue cultures infected with aster yellows: morphological analogies with Mycoplasma hominis.

Several forms of mycoplasma-like bodies (MLBs) were observed in electron micrographs of phloem cells from explants infected with aster yellows disease. The structures were found only in explants 11--25 days old, when the degenerating MLBs were first observed. They resembled those described by Anderson and Barile in 1965 for Mycoplasma hominis. A sequence of events in the degeneration of MLBs is postulated and morphological analogies with degenerating M. hominis are discussed.