Plant Regeneration from Suspension Cultures in Japanese Morning Glory (Ipomoea nil (L.) Roth.)

Abstract

Embryogenic suspension cultures of Japanese morning glory (Ipomoea nil (L.) Roth.) cv. Violet were established from immature embryos by using a liquid N6-based medium (N6 inorganic salts and MS organic constituents) with 3 mg · liter-1 NAA and 60 g · liter-1 sucrose. Suspension cells showed a 1.5 to 2.5-fold increase in packed cell volume in one week. When suspension cell clusters were transferred to MS media, containing 0-0.5 mg · liter-1 NAA, 60 g · liter-1 sucrose, and 3.2 g · liter-1 Gellan gum, 3.57-3.90 somatic embryos/cell clusters were produced. For shoot formation, these somatic embryos were transferred to MS medium with 0.2 mg · liter-1 IAA, 2 mg · liter-1 BA, 30 g · liter-1 sucrose and 10 g · liter-1 agar. The developing shoots were transferred to 1/2MS medium (half-strength MS inorganic salts) containing 30 g · liter-1 sucrose and 10 g · liter-1 agar for rooting. As many as 40 plantlets were obtained from a 0.1 ml packed cell volume of suspension cell clusters in 3-4 months. That the regenerated plants were successfully transferred to pots demonstrates that this plant regeneration system may facilitate micropropagation of mutant Japanese morning glory via embryo culture and transformation in I. nil.