RESUMO
Axenic callus and shoot cultures of pyrethrum have been shown to be capable of pyrethrin biosynthesis. The influence of explant source on the biosynthetic capacity in cultured tissue was examined. Explants of various plant organs were taken from high and low yielding plant selections. The conditions necessary for the establishment of these explants in culture are described. Analytical screening of the tissue lines enabled the selection of a few "high yielding" strains which were derived from high yielding plant selections. Differentiated cultures tended to produce more pyrethrins than did callus cultures.
RESUMO
Leaves of Chrysanthemum cinerariaefolium at various stages of development were found to contain differing amounts of pyrethrins. The variation corresponds to the number of oil glands per unit area of leaf surface. Leaf tissue was mechanically and enzymatically separated into lower and upper epidermis and mesophyll cells. Pyrethrins were found to be present in each layer, more pyrethrins were present in the epidermal layers of young leaves while the mesophyll cells were found to have higher pyrethrins in older, more mature cells.
RESUMO
The classical Golgi apparatus has not been observed in the several strains of Tetrahymena pyriformis examined in this laboratory at the ultrastructural level when the ciliates are grown vegetatively. However, sexually active strains, when starved for the purpose of inducing conjugation, contain stacked saccules in the oral region. When such opposite mating types are mixed for mating, the stacked saccules become swollen at their ends and vesicles appear to pinch off from them. These bodies possess the configuration of the classical Golgi apparatus of other eucells. Vesicles seem to be formed from the saccules just prior to, and toward the end of conjugation, suggesting a relationship with the mating process.