Alfalfa witches’ broom in Czechoslovakia and demonstration of mycoplasma-like organisms in the affected plants

Alfalfa witches’ broom manifested by an expressive increase in the number of stems and dwarfing of the affected plants was found in Czechoslovakia. The disease is not saptransmissible and was transmitted by grafting to healthy alfalfa plants. The disease occurrence is sporadic. The symptoms observed in comparison with those described in Australia and USA are mild and inconspicuous. Electron micrographs of ultrathin sections showed the presence of numerous mycoplasma-like organisms (MLO) in diseased but not in healthy phloem tissues.