NON-RANDOM CHROMOSOME ASSOCIATIONS AT DIPLOTENE AND DIAKINESIS IN A TETRAPLOID CLONE OF VACCINIUM AUSTRALE SMALL

In a cultivated tetraploid genotype (2n=4x=48) of Vaccinium australe Small the chromosome associations at late prophase of the first meiotic division and the separation of the chromosomes at anaphase I and anaphase II were investigated.Of the 223 PMC's analyzed one quarter of them displayed only bivalent associations; the remaining displayed both bivalent and quadrivalent associations. In about 3% of the PMC's, hexavalents were observed. No univalents, trivalents or pentavalents were found. The non-randomness of the chromosome associations is interpreted as resulting from obligatory pairing and localized distal chiasma.In spite of multivalent formation, in 115 PMC's studied, separation of the chromosomes at anaphase I is regular and in 95 daughter nuclei 24 chromosomes were counted. At anaphase II, the great majority of the nuclei revealed regular separation of the chromosomes and consequently numerically balanced gametes are produced.