Efficient embryogenic callus formation in sweet potato (Ipomoea batatas (L.) Lam.)

Abstract

Shoot apices of sweet potato (Ipomoea batatas (L.) Lam.) were cultured on LS medium containing 3 % (W/V) sucrose, 0.32 % (W/V) gellan gum and various concentrations (0, 0.5, 1, 2, 4 mg/l) of eight kinds of auxins. More than 90 % of shoot apices from cv. Kokei 14 formed embryogenic callus on the medium containing 0.5 to 1 mg/l 4-fluorophenoxyacetic acid (4 FA) or 1 mg/l 4-amino-3,5,6-trichlorophenoxyacetic acid (picloram). Genotypic differences in embryogenic callus formation were observed in eleven cultivars when their shoot apices were cultured on LS medium supplemented with 1 mg/l picloram. Numerous somatic embryos were formed from embryogenic calli when the calli were transferred onto LS medium supplemented with 4 mg/l abscisic acid (ABA), and 1 mg/l gibberellic acid (GA3). Somatic embryos germinated on LS medium with 0.05 mg/l ABA.