Cytohistological analysis. On the basis of an anatomical study, it
appeared that BA and Kin induced callus formation in the leaf mesophyll
layers. The callus was essentially associated with the spongy
parenchyma and scarcely associated with the palisade parenchyma
cells. The buds originated exogenously at the callus surface, and
newly formed vascular areas in the callus had evident connections
with vascular bundles at the base of buds and often with the vascular
region of the original leaf segments (Figs. 2 a and b).
Darlington and Wyle (1955) reported for the genus Sinningia a
basic chromosome number, x = 14. Sugiura (1936) reported, for
Sinningia speciosa anthers in meiotic metaphase I, 2n = 4x = 56.
To these data another basic set with x = 13 should be added. In
fact, in our work on Sinningia speciosa f. fyfiana cv. Tigrina red we
found 13 bivalents in embryo mother cells at meiotic metaphase I in
ovaries (Fig. 2 c) and 2n = 2x = 26 in somatic metaphase of root
tip cells of the mother plant (Fig. 2 d). This was confirmed in all
subcultures (Fig. 2 c).