Regeneration from long-term cell suspension cultures of tepary bean (Phaseolus acutifolius).

Plant regeneration has been achieved from long-term cell suspension cultures established from leaf derived callus of tepary bean (Phaseolus acutifolius). The proportion of densely cytoplasmic cells in suspension culture increased when cultured in the L-6 medium with 54 μM NAA and 2 μM KN. Filtration of the cells at each of five consecutive subcultures resulted in the isolation of a plant regenerating cell line (TB 686), which is being maintained in L-6 medium with 4.5 μM 2,4-D and 2.3 μM zeatin. Differentiated green cell aggregates were obtained when cells from maintenance medium were transferred to the same medium with 10 μM BA. Embryo-like structures developed from these aggregates on L-6 medium with 2.3 μM zeatin, 0.69 μM GA3 and 1.5 μM NAA. Plantlets regenerated from these structures when they were cultured on L-6 medium with 7.0 μM NAA and 1.0 μM KN. Plant regeneration from the cell line remained relatively constant for 270 days. Regenerated plants were grown to maturity in the greenhouse.