Mycology Plant Pathology

Phyllody is a condition in which floral parts are transformed into leaf-like structures. It is caused by a group of microorganisms called mycoplasma-like organisms (MLOs), now more accurately referred to as phytoplasmas, which are wall-less bacteria-like pathogens.
Option (A) Nematode: Incorrect. Nematodes are parasitic worms and do not cause phyllody.
Option (B) Mycoplasma: Correct. Phyllody is caused by phytoplasmas, a type of mycoplasma.
Option (C) Bacteria: Incorrect. Although phytoplasmas are related to bacteria, phyllody is not caused by typical bacteria.
Option (D) Virus: Incorrect. Viruses cause other diseases, but not phyllody.