Adventitious Bud Development of Soybean Hypocotyl Sections in Culture¹

Abstract

Tissue culture methods were used to study the capacity of soybean ( Glycine max (L.) Merrill) to differentiate adventitious buds. Hypocotyl sections from the cultivar ‘Dunn’ were placed on various media for preliminary observations, and ‘Corsoy’ was tested later to determine if ‘Dunn’ responses were variety‐specific. Those sections placed on media containing 0.5 to 2.0 mg/liter 2,4‐dichlorophenoxyacetic acid (2,4‐D) or 2.0 mg/liter 2‐naphthylacetic acid (NAA), and 0.5 or 2.0 mg/liter kinetin, produced callus tissue with or without roots. Sections placed on media containing 0.1 to 2.0 mg/liter indole‐3‐acetic acid (IAA) and either 15% (v/v) coconut milk (CM) or 0.5 or 2.0 mg/liter kinetin formed little or no callus, but instead enlarged slightly and produced roots (35 to 90% of sections) or shoots (1 to 8% of sections), depending on the particular treatment. Roots usually formed on sections that previously had differentiated shoots, but shoots seldom formed on sections that already had roots. Soybean hypocotyl sections, when cultured under the appropriate conditions, formed adventitious buds.