CYTOLOGICAL OBSERVATIONS ON THE CALLUSES AND THE RESTORED THALLUSES IN MARCHANTIA POLYMORPHA

Abstract

Calluses of M. polymorpha produced from female gemmae were subcultured in the various media and cytological observations were made on these calluses and the thalluses restored from calluses. In 4 media used for subcultures, M-4 medium (a modified Miller''s medium supplemented with 10% coconut milk) promoted the growth of calluses most effectively, and M-3 medium (a modified Miller''s medium supplemented with 500 ppm casamino acid) promoted the next best growth. M-2 medium (a modified Miller''s medium) and M-1 medium, used for inducing the calluses, did not promote as much. The observations of chromosomes in calluses showed that the number of abnormal cells (polyploid and aneuploid) increased in contrast to the number of normal haploid cells as a result of subcultures. The frequency of the abnormal cells was found to be the highest in M-4 medium. When light was illuminated on the calluses which were cultured in the dark, without changing the medium, the calluses soon turned green and grew further. The restored thalluses could be easily obtained by culturing the calluses in the inorganic media. It was found that among the restored thalluses diploid (n = 18) and aneuploid (n = 12, 14) thalluses were included in addition to many normal haploid thalluses (n = 9).