title: Early Stages of Somatic Embryo Differentiation from Callus Cells of Bean (Phaseolus vulgaris L.) Grown in Liquid Medium.
abstract: Shoot apices of bean cultivars (Phaseolus vulgaris) were cultivated in vitro. Callus induced by MS medium in the presence of KIN (10 μM), 2,4-D (5 μM), and IAA (10 μM) displayed optimum proliferation for 14 cultivars, intermediate growth for 8 cultivars, and poor growth for the remaining 14 cultivars. Callus derived from shoot apices of these 36 bean cultivars were transferred into liquid media. Inorganic PC-L2 salts with 2,4-D (10 μM) and casein hydrolysate (2 g · 1-1) was sufficient to sustain growth of cells in liquid medium. These liquid cultures had different growth characteristics dependent upon genotype, amount of initial inoculum, and culture media. Cultivars Moruna, Pirata-1, and Linea-29 were able to produce globular embryo structures during liquid culture. Callus cells of «carioca» when transferred to a new liquid medium containing KIN (0.5 mg · l(-1)), 2,4-D (0.2 mg · l(-1)) and casein hydrolysate (50 mg · l(-1)) produced embryogenic cells and somatic embryos at an early state of development. The globular structures, embryogenic cells, and somatic embryos did not develop further following transfer to solid media.
authors.affiliation: Department of Genetics, Institute of Agronomy, P.O. Box 28, Campinas, SP Brazil.
authors.forename: I S
authors.initials: IS
authors.lastname: Martins
authors.forename: M R
authors.initials: MR
authors.lastname: Sondahl