干旱区生态环境知识资源中心

Present cytological investigations recorded the first ever diploid chromosome (n=8) count in 9 accessions under 3 morphovariants (MV) of Clematis graveolens. Out of 9 accessions, individuals of MV-II and 3 individuals of MV-III depicted the phenomenon of cytomixis involving chromatin transfer among proximate pollen mother cells (PMCs) during male meiosis which occurred through narrow and broad cytoplasmic channels from early prophase-I to telophase-II. The migration of chromatin material has been observed to be partial as well as complete which resulted into the formation of hypo-, hyperploid and enucleated PMCs. Cytomixis induced various meiotic irregularities into PMCs such as pycnotic chromatin, interbivalent connections, chromatin stickiness, syncyte PMCs, laggards/micronuclei and chromatin bridges, out of plate bivalents, late disjunction of bivalents and PMCs with multiple poles. These meiotic abnormalities resulted into abnormal sporad formation and 1.68-10.00% pollen sterility Furthermore, the range in size of pollen grains in the species is affected considerably due to cytomixis and the process of pollen fusion where 2-3 pollen grains were fused resulting into very large sized pollen grains. The large sized pollen grains in some accessions were also resulted as the products of syncyte PMCs.