Embryogenic callus induction and regeneration in anther culture of noug (Guizotia abyssinica (L.F) Cass.)

Abstract

Two released noug varieties, Shambu and Fogera, were used for this experiment. Initially, two experiments were conducted to identify the appropriate morphological stage of capitula (buds) for harvesting maximum number of responsive anthers and to study the optimum cold pretreatment duration for callus induction from the anthers. Three culture media, MS, B₅ and NN, were employed for callus induction. MS medium, with nine different combinations of KN and IAA, was used for shoot regeneration study. Three different concentrations of IBA and growth regulator-free MS medium were used for the rooting experiment. The results showed that capitula, fully or slightly covered by sepal having whitish-green or greenish-yellow anthers, were the optimum stages of harvesting capitula; callus was efficiently induced when the capitula were pre-treated at 4^°C for 24 hours. The types of calli induced significantly (P≤0.05) varied among the three media. Embryogenic calli were mainly produced in NN and B₅ media, while varying in texture and colour. High percentage of embryogenic calli (80%) was induced on NN medium from the variety Shambu, followed by b₅ medium showing 40% inductions for both varieties. Among nine different KN and IAA combinations, 2 mg/l KN combined with 1 mg/l IAA, was the most efficient for shoot regeneration. It was also found that 0.5 mg/l IBA was optimum for root induction. In the growth room as well as in the glasshouse, the survival rate of regenerants was generally better for the variety Shambu than for Fogera.