干旱区生态环境知识资源中心

Male meiosis and pollen fertility studies have been performed in 35 species belonging to 25 genera and 13 families of Polypetalae from the Dalhousie hills. Impatiens laxiflora (n=6) was counted chromosomally for the first time. Corydalis cornuta (n=8), Erysimum hieracifolum (n=16), Arenaria serpyllifolia (n=10), Drymaria diandra (n=13), Geranium lucidum (n=14), Nasturtium officinale (n=16), Geum roylei (n=21) and Chaerophyllum reflexum (n=11) are worked out chromosomally for the first time in India. New cytotypes are recorded for Thalictrum saniculiforme (n=14), Drymaria diandra (it 13), Geranium lucidum (n=14) and Chaerophyllum reflexum (n=11). Present chromosome counts for the rest of the species substantiate earlier reports by other researchers. Intraspecific diploid (n=12) and tetraploid (n=24) cytotypes recorded presently from Dalhousie hills in Oxalis corniculata are morphologically indistinguishable. The phenomenon of cytomixis involving inter PMC (pollen mother cell) migration of chromatin material has been observed in Ranunculus diffusus (n=16), Thalictrum foliolosum (n=7), T saniculiforme (n=14), Gypsophila cerastioides (n=15), Oxalis corniculata (n=24), Murraya koenigii (n=9), Geum roylei (n=21), Potentilla atrisanguinea (n=21) and Pimpinella diversifolia (n=9). Cytomixis in these species results in various meiotic abnormalities and heterogeneous sized pollen grains. In the remaining species, the meiosis is normal, leading to high pollen fertility.