In vitro shoot multiplication and callus induction in Gladiolus hybridus Hort

The present investigation was carried out to study the In vitro shoot multiplication and callogenesis in Gladiolus. For this purpose, cormel, meristem and leaf explants were chosen. Different concentrations of BAP i. e., 0.5, 1.0, 1.5, 2.0 or 2.5 mgL(-1) (2.22, 4.44, 6.66, 8.88 or 11.10 mu M) were supplemented to MS medium. Both cormel and meristem explants showed maximum multiplication on MS medium containing 1 mgL(-1) BAP. At this particular concentration of BAP, 16 shoots (2 cm or longer) were developed from cormel while 10 from meristem explants after 8 weeks of culture initiation. Thus cormel explants proved to be a better source for shoot multiplication as compared to meristem. Further shoot multiplication in successive subcultures was also possible. Rooting of In vitro grown shoots was achieved on MS (half basal) medium supplemented with 0.5mgL(-1) (2.69 mu M) NAA or 2mgL(-1) (9.84 mu M) IBA. Out of 14 tested media for callus induction, 3 media were found effective for callus induction from cormel explants. Only 2 media could support callus induction from leaf explants. Rooting was observed in one month old cormel-derived callus cultures when NAA was used at either 0.3 or 0.4 mgL(-1) concentration (1.61 or 2.15 mu M). Sporadic shoot regeneration was observed from cormel explant-derived callus cultures in MS medium supplemented with 2 mgL(-1) (9.05 mu M) 2, 4-D and 1.0 mgL(-1) (4.44 mu M) BAP.