In vitro regeneration of niger (Guizotia abyssinica Cass.): using cotyledon and hypocotyl explants

Callus induction and shoot formation from hypocotyls and cotyledons of Guizotia abyssinica Cass. has been achieved. Six to eight-day-old hypocotyl segments and cotyledons were cultured on MS medium containing different concentrations of NAA, IAA and BAP. Among the various concentrations tested, 0.5 mg/l NAA in combination with 1 mg/l BAP was found to be the best for maximum callus induction of hypocotyl explants. Furthermore, 2 mg/l IAA in combination with 1 mg/l BAP was the best for callus induction of cotyledonary explants. Highest percentage of shoot formation (60%) was obtained when cotyledons were cultured on medium supplemented with 3.0 mg/l IAA in combination with 1.0 mg/ l BAP. Maximum number of shoots per explant (20.3) was obtained from medium containing 0.1 mg/l NAA in combination with 1 mg/l BAP. The types of explant, growth regulator combinations and genotypes were showed significant effect on shoot regeneration. The elongated shoots were successfully rooted on media supplemented with IBA at a concentration of 0.5 mg/l. The shoots were established in soil where 65% of them survived. Morphologically aberrant plants were not observed.