Studies on the Differentiation in Cultured Cells I

Embryogenesis in Three Strains of Solanum Callus

Abstract

The two strains of callus, one strain BD that forms “embryo” and the other strains BND that shows no differentiation, were isolated from the callus of the common origin after two years of culturing. The BD strain formed chlorophyll, while BND, which is a translucent callus with a good rate of multiplication, showed no chlorophyll formation. The KA, a different strain, showed no differentiation of organs on the basic culture medium.
Using these three strains, the effect of IAA and kinetin on organ formation was experimented. The BD differentiates “embryos” on the basic medium, its formation being controlled by IAA. In the KA, bud differentiation is induced under white fluorescent light in the range of suitable combinations of IAA and kinetin.
The embryogenesis of BD is similar to that of the embryo in an ovule.
In KA, development of spherical colonies precedes adventive bud formation. In this case, a base for buds is formed which then grows into adventive buds.
In BND, cultured cells are variable in nature, so the “embryo” forming portion is maintained by selection.
The conditions for inducement of buds differ with types, but even in the same type they differ with strains or callus age, so that generalizations on the bud inducement process are now difficult.
The previous papers1, 2) reported studies on Tradescantia and Paeonia calli and revealed that the calli were generally mixoploidal cell colonies which were lacking cytological uniformity. Hitherto the studies of induccing certain organs from colonies have been attempted for the purpose to observe whether or not uniformity of calli is gained to form an entire plant.
In the present paper the effects of auxin and kinetin on the embryogenesis of the three strains of calli derived from the two forms of Solanum will be reported.