Conidial Nucleation in Stemphylium botryosum

Abstract

Conidial nuclcation in an isolate of  Stemphylium botryosum obtained from lucerne was investigated using the HCl-Giennsa technique. Conidiophores arose as anucleate buds into which somatic nuclei migrated. After attaining varying stages of complexity the terminal cell, which was strictly monokaryotic. developed into a conidium. Division of the young conidial nucleus and subsequent cell wall formation resulted in a multicellular conidium Conidial cells contained either one, two or four nuclei. As all the conidial nuclei are derived from the single nucleus of the terminal conidiophore cell, the whole conidium is homokaryotic. There is thus no mechanism for the psrpetuation of heterokaryons through the conidia.