Chromosome Associations in the First Meiotic Division in Three Tetraploid Clones of Vaccinium Corymbosum L

The analysis of chromosome pairing in three tetraploid cultivars of Vaccinium corymbosum L. revealed chat the great majority of bivalents were involved in pseudo-multivalent associations. The number of independent bivalents (not involved in formation of multivalents) increased from diakinesis to metaphase I.The pseudo-multivalents at diakinesis and at MI are the consequence of incomplete relaxation of the synizetic knot, a dense chromatic mass observed in early prophase. Factors that might affect the relaxation process are discussed.