Effect of carbohydrates on callus induction and regeneration ability in Brassica napus L.

The effect of 1%, 3% and 10% fructose, glucose, sucrose and ribose on callus induction and organogenesis was studied in Brassica napus L. cv. Evita. Hypocotyls and cotyledons of 7-day-old seedlings were used as explants. MS (Murashige and Skoog, 1962) was the basal medium. Calluses were produced from both types of explants in the presence of 2,4-D. There were significant differences in the frequency of callus induction between ribose and other sugars tested, as well as between low (1% and 3%) and high (10%) sugar concentrations. Irrespective of sugar type, callus induction was significantly lower on ribose- containing media and at high concentration. On hormone-free media, callus tissue formed very exceptionally and only from cotyledons. The amounts of callus tissue produced were highest on MS with glucose, followed by sucrose and fructose. In the regeneration experiments, explants were cultured on MS with 2,4-D as the sole growth regulator, and with NAA and kinetin. No regeneration occurred on medium with 2,4-D. In the presence of NAA and kinetin, organogenesis was observed only on media with 1% and 3% sugars, but on ribose the number of organs produced was very low. The highest regeneration ability occurred on sucrose-based medium.