Cytomixis induced meiotic abnormalities in pollen mother cells of clematis Flammula L. (Ranunculaceae)

Abstract

Meiotic studies carried out in the diploid (2n=2x=16) Clematis flammula L. revealed the occurrence of cytomixis. Chromatin transfer is observed from early prophase up to tetrad stage. Although the percentage of PMCs involved in chromatin transfer is low, but it definitely impairs the meiotic process. Cytomixis induces various other associated meiotic abnormalities which are ob- served at different meiotic stages. These meiotic abnormalities include; chromatin stickiness, lag- gards and chromatin bridges at anaphases and telophases, spindle abnormality, micronuclei at telophases and tetrad stages, micromicrospores and included micronuclei in microspores. Conse- quent to chromatin transfer, some pollen malformation and pollen grains of heterogenous sizes are resulted which are classified into small, medium and large sized. Another interesting phenomenon which has been observed during the present study is the occurrence of included micronuclei in the microspores and micrmicrospores in tetrads. Cytomixis and other meiotic abnormalities are reported for the first time in the species. We here also report for the first time the occurrence of B-chromo- some in the species. ©2008 The Japan Mendel Society.