A Case of Cytomixis, Cell fusion, Syncyte and Dimorphic pollen grains in Angelica glauca from the cold deserts of North-West Himalayas

A Case of Cytomixis, Cell fusion, Syncyte and Dimorphic pollen grains in Angelica glauca from the cold deserts of North-West Himalayas

Angelica glauca Edgew. (Apiaceae) has been cytologically studied from the cold deserts of Ladakh division of North-West Himalayas in India. Besides re-reporting the diploid chromosome count of 2n=22 from India, the analyzed accession depicted the phenomenon of cytomixis, cell fusion leading to syncyte PMCs and dimorphic pollen grains. Majority of the pollen mother cells (PMCs) exhibited 11 bivalents at Metaphase-I, 11:11 chromosomes at Metaphase-II and equal sized pollen grains. However, a few PMCs showed the phenomenon of cytomixis involving chromatin transfer and fusion resulting into syncytes. These syncytes could be detected in preparations due to their larger size compared to typical (2x) PMCs and showed 22 bivalents. The products of typical and syncyte meiocytes yielded dimorphic pollen grains. Such pollen grains with different genetic constitution could play an important role in the origin of intraspecific euploids.