In Vitro Propagation of Sterile Mutant Strains in Japanese Morning Glory by Sub-culturing Embryoids Derived from an Immature Embryo

Abstract

The Japanese morning glory Ipomoea nil (L.) Roth. has mutant strains among which the group “demono” is sterile as a result of severe phenotypic alterations of the leaves and flowers. Hence, its seed propagation requires time and effort. Successful plant regeneration of “demono” mutant Japanese morning glory strains was established from immature embryos from heterozygous stocks by using a MS medium with 3 mg · L^-1 NAA and 60 g · L^-1 sucrose. Embryoids, derived from the immature embryo culture, were maintained in monthly subcultures, and then transferred to a MS medium with 0.2 mg · L^-1 IAA and 2 mg · L^-1 BA for shoot formation. The developing shoots were transferred to 1/2 MS medium (half-strength MS inorganic salts) for rooting, and the regenerated plants were successfully transferred to pots. Embryoids that produced “demono” plants were selected, based on the shapes of the regenerated shoots and flowers. It was possible to maintain successfully the regeneration ability of the embryoids of “demono” plants for more than one year, no severe somaclonal variations were observed.