In vitro propagation of Hosta sieboldiana using excised ovaries from immature florets

Ovaries from immature florets were selected as an improved explant source for in vitro cultures of Hosta sieboldiana. Culturing for 30 days on a modified Murashige & Skoog (MS) medium supplemented with thiamine (0.4 mgl^-1) and glycine (2.0 mgl^-1) induced the highest frequency of callus growth at 5.4 M NAA and 4.4 M BA, and the highest frequency of shoot initiation at 0.4 M BA. The severed basal portion of the ovary was the site of shoot growth. Eliminating phytohormones and adding 80 mgl^-1 of AdSO₄ significantly enhanced root initiation. Rooted plantlets were established in sterilized vermiculite containing MS mineral salts. A cold treatment (1°C) of 30 days in the dark was necessary to break dormancy of the rooted plantlets.Abbreviations AdSO₄ adenine sulfate - BA benzylaminopurine - NAA naphthaleneacetic acid