Cytology of Chlamydospore Development in Protomyces macrosporus Unger

Abstract

Observations are presented on the cytological behavior of Protomyces macro-sporus Unger in artificial culture and within an infected coriander (Coriandrum sativum L.) stem. The haploid spores bud into colonies with mitoses. Diploid condition is brought about by copulation between 2 compatible haploid spores accompanied by nuclear fusion. The diploid spores only are pathogenic to the host producing branched, septate hyphae with multinucleate cells in the inter-cellular spaces of nonvascular tissues in the host. Hyphal development initiates in vitro chlamydospore formation similar to that within the host tissues, thus in-creasing the primary inoculum potential of the pathogen. The haploid chromosome complement of n=2 is confirmed again.