Chromosome conspectus of Kashmir Himalayan species of the genus Potamogeton L.

The present study represents an original investigation on the chromosome number and meiotic behaviour of eleven Potamogeton species inhabiting lotic and lentic freshwater bodies in the Kashmir Himalaya. The chromosome number of P. berchtoldii (2n = 4x = 28), P. crispus (2n = 12x = 84) recorded during the present study differed from earlier reports, while chromosome count for P. amblyphyllus (= Stuckenia amblyphyla) is newly reported for the genus. In P. natans two cytotypes were identified: tetraploid (2n = 4x = 52) and octoploid (2n = 8x = 104), the latter being the first report. The species characterized by abnormal anaphasic segregation also had low pollen fertility and fruit set. The present study also correlates base number and ploidy level with leaf habit, pollination efficiency and fruit set.