01414naa a2200169 a 450000100080000000500110000800800410001910000160006024501220007626000090019852009200020765000220112770000160114970000170116570000150118277300470119716478732023-05-17       1992    bl uuuu     u00u1 u    #d1 aRAJA, V. G.  aPloidy-dependent genomic stability in the tissue cultures of ornamental phlox drummondii Hook.h[electronic resource]  c1992  aComparisons of the chromosome numbres, 2C nuclear DNA amounts and karyomorphology were made in explant cultures of diploid (2n = 2x = 14) and autotetraploid (2n = 4x = 28) Phox drummondii. In 6-36 week old calli derived from diploid internodal segment explants, and in cells of root tips regenerated from such callus, marked differences were observed in chromesome number. The chromosome numbers ranged from 2n = 14 to 2n = 100 and DNA amounts from 8.20 to 63.20 pg in the diploid derived callus, while the extent of variation was much reduced in the regenerated roots. In contrast, the autotetraploid cultures were characterised by the maintenance of the same chromosome number and DNA amounts as the mother plant. Modified chromosome structures were not apparent in any of the cultures. The possible reasons for the chromosomal instability at the diploid level and stability at the tetraploid level are discussed.  aCultura de Tecido1 aKOUL, K. K.1 aRAINA, S. N.1 aPARIDA, A.  tPlant cell reportsgv. 12, p. 12-17, 1992.