Karyotypic analysis of Plasmodiophora brassicae based on serial thin sections of pachytene nuclei

Abstract

Reconstructions based on electron microscopy of serial thin sections of three pachytene nuclei of Plasmodiophora brassicae Woron. showed 20 synaptonemal complexes (SCs) and thus indicated a haploid chromosomal number of 20. No recombination nodules were observed, but modified regions with lateral elements more electron opaque than the rest of the SCs were reported. Ends of SCs attached to the nuclear envelope and clustered near the two centriole pairs.