Studies of the mycoplasma-like organism (MLO) in spinach leaves affected by the aster yellows disease

摘要: Mycoplasma-like organisms (MLO) were found in the phloem of spinach (Spinacia oleracea L.) leaves infected with agent aster yellows disease by means leafhopperMacrosteles fascifrons Stal. The MLOs occurred mainly mature sieve elements but recorded occasional parenchyma cells as well. MLO showed typical features this organism. majority ovoid or spherical, some irregular form elongated. larger bodies commonly accompanied small which appeared to originate from budding. Profiles suggesting binary fission and filamentous forms containing condensations cytoplasm present. bounding membrane trilaminate structure, DNA-like fibrils discernible those that had an electron lucent central region. In denser obscured. ribosomes distinctly smaller than host cytoplasm. degenerating disorganizing collapsing response infection. Structures may be confused are described.