Abstract
Variation in meiotic behaviour was analysed in accessions belonging to four chromosomal races (2n=36, 44, 54 and 56) in two species of Cenchrus.
All the accessions possessed the same chromosomal irregularities during the process of meiosis. The aberrations encountered were essentially of the same kind, but their frequencies were dissimilar in different accessions. These irregularities were the presence of univalents and multivalents, lagging chromosomes and chromosome bridges at anaphase I, laggards at anaphase II and numerous micronuclei at both the dyad and tetrad spore stages. These are commonly associated with polyploidy and hybridisation and both the factors are involved in the evolution of the complex.
Evidence from chromosome associations points to the allopolyploid nature of the chromosomal forms and the segmental homology of the duplicated genomes.
