Presently, detailed cytological investigations have been carried out in 4 accessions of Anemone rivularis Buch.-Ham. ex DC, collected from the cold deserts of Lahaul-Spiti, Kinnaur, and Kullu districts of Himachal Pradesh (India). The phenomenon of cytomixis involving chromatin transfer among proximate pollen mother cells (PMCs) during male meiosis is recorded for the first time in the species. The effects of cytomixis on meiosis and pollen grains have also been discussed. In spite of the

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... nce of intraspecific aneuploid and polyploid cytotypes (2nϭ14, 16, 24, 28, 48), all the accessions of the species unequivocally share the same diploid chromosome number, 2nϭ 16. The accession studied from Kothi (Kullu) shows perfectly normal meiotic behaviour, cent per cent pollen fertility and uniform sized pollen grains. However, the accessions analyzed from Keylong and Kishori (Lahaul-Spiti) and Sangla (Kinnaur) show the phenomenon of cytomixis involving chromatin transfer among proximate PMCs, and associated meiotic abnormalities like chromosome stickiness, laggards and bridges at anaphase/telophase, micronuclei, some pollen malformation and pollen grains of heterogeneous sizes.