Meiotic Studies in Species from the Cold Deserts of Lahaul-Spiti and Adjoining Areas (Northwest Himalaya)

Abstract

Meiotic investigations were carried out on 29 species of 13 Polypetalae families from the cold deserts of Lahaul-Spiti and adjoining areas of north-west Himalaya. Additional/varied cytotypes have been reported for two species for the first time. The present chromosome count of 2n=18 in Hypericum elodeoides adds a new cytotype to the existing diploid (2n=2x=16) chromosome number. The meiotic count of 2n=2x=14 in Potentilla fruticosa var. rigida adds a new diploid cytotype to the already existing tetraploid (2n=4x=28) cytotype. The chromosome numbers of 10 species viz. Aquilegia fragrans (n=7), Silene vulgaris (n=12), Astragalus bicuspis (n=8), Cicer microphyllum (n=8), Potentilla fruticosa var. rigida (n=7), Melilotus officinalis (n=8), Rosa webbiana (n=7), Bergenia stracheyi (n=17), Sedum ewersii (n=11) and Datisca cannabina (n=11) are new records for India. The cytomixis involving the inter pollen mother cell transfer of chromatin is observed in Caltha palustris, Astragalus bicuspis, Meconopsis aculeata, Melilotus officinalis, Potentilla fruticosa var. rigida and Trifolium pratens. In Caltha palustris the cytomixis (20–28%) results into various meiotic abnormalities and heterogeneous sized pollen grains. In other species the frequency of PMCs (pollen mother cells) involved in chromatin transfer is very low (0.1–1%) without affecting the pollen fertility.