Somaclonal variation in Tricyrtis hirta plants regenerated from 1-year-old embryogenic callus cultures

Morphological variation in Tricyrtis hirta plants regenerated from heavy ion beam-irradiated embryogenic calluses

“…All the 4 tetraploid regenerants had longer shoots, thicker stems, larger and deeper green leaves, and larger flowers compared with the control, division-derived plants. Tetraploid plants have already been regenerated from long-term (1-yearold) embryogenic callus cultures of T. hirta, and they showed similar morphological characteristics to those of the tetraploid regenerants obtained in the present study (Nakano et al 2006b). Since relatively long-term (8-month-old) embryogenic callus cultures were used as a target material for irradiation in the present study, the 4 tetraploid regenerants may be resulted from somaclonal variation rather than from ion beam irradiation.…”

“…In our previous report, 2 types of somaclonal variants were observed among regenerants from 1-year-old embryogenic calluses of T. hirta: one type was a tetraploid variant, which was also obtained in the present study as described above; and the other type was a diploid, severely dwarf variant with crimped leaves and many malformed flowers (Nakano et al 2006b). Although several dwarf variants were regenerated from ion beam-irradiated embryogenic calluses in the present study, all of them had neither crimped leaves nor malformed flowers, and were clearly distinguishable from the severely dwarf somaclonal variant reported previously (Nakano et al 2006b).…”

“…Nonirradiated embryogenic calluses were also transferred to PGRfree, half-strength MS medium. Regenerated plantlets were acclimatized, separately transplanted to pots (18 cm in diameter), and cultivated in the greenhouse as previously described (Nakano et al 2006b). Divisions, each containing one small shoot, from the mother plant of the embryogenic calluses were transplanted to pots and cultivated as controls under the same conditions.…”

“…Divisions, each containing one small shoot, from the mother plant of the embryogenic calluses were transplanted to pots and cultivated as controls under the same conditions. Three years after cultivation in the greenhouse, morphological characterization and ploidy level analysis were performed on regenerants from irradiated and non-irradiated embryogenic calluses and the control, division-derived plants according to Nakano et al (2006b). For morphological characterization, number of shoots per plant, mean shoot length of the longest 3 shoots, mean number of nodes per shoot of the longest 3 shoots, mean leaf length and width of randomly selected 9 leaves (3 leaves each from the longest 3 shoots), number of flowers per plant, mean flower length and diameter of randomly selected 3 flowers were recorded for each plant at the flowering stage.…”

Genetic stability of micropropagated plants of Crambe abyssinica Hochst using ISSR markers

“…The reasons accounting for somaclonal variations remain unclear, although factors such as culture duration, number of subcultures or transfers (Borse et al, 2011), phytoregulators (Biswas et al, 2009), explant type (Chuang et al, 2009), passage through the indirect callus phase (mass of undifferentiated cells with regeneration potential) (Peredo et al, 2006), genotype (Khan et al, 2009), culture medium composition (Lutts et al, 1998), and ploidy and mosaicism levels (Nakano et al, 2006) are considered capable of inducing this variability in vitro.…”