1959 Volume 24 Issue 4 Pages 523-531
The evolution of diverse morphological forms in Convolvulus pluricaulis Chois. was found to be mainly due to intraspecific polyploidy. The tetraploid showed thick and large leaves with a higher leaf index. An increase in the size of stomata, epidermal and palisade cells was associated with tetraploidy. The number of stomata and epidermal cells per unit area was inversely proportional to the euploid increase in chromosome number. The tetraploid which was late in flowering further characterised itself by an enlargement in flower, pollen and seed size. The pollen fertility in diploid as well as tetraploid was above 95 per cent.
The chromosome numbers of diploid and tetraploid were determined as n=9 and n=18, respectively. The details of meiotic division in the two have been described. The cytological data in conjunction with morphological studies suggest that the tetraploid in all probability arose as a result of autopolyploidy or segmental polyploidy.