Abstract
PRELIMINARY SEROLOGICAL RESEARCHES ON MECHANISM OF TUMOR INDUCTION IN NICOTIANA HYBRIDS. According to GOODSPEED'S phyletic scheme, based on a cytogenetic evidence, both Nicotiana rustica and N. paniculata should be assigned to the sub-genus Rustica, while N. langsdorffiii and N. sanderae fit with the sub-genus Petunioides. Indeed the fact that genetical tumors are produced by the hybrids of these species only when the parents belong to different sub-genera, seems to support GOODSPEED'S views, just as KOSTOFF'S hypothesis of tumor production as a consequence of uncongeniality and incompatibility of parent's protein set, receives by this scheme a valid support.
Immunological research work has been carried out to test the possible affinities of the protein sets of the four Nicotiana species. It was observed that the protein set of N. paniculata is more similar to the protein set of N. langsdorffiii — a species included in a different sub-genus and whose hybrids with. N. paniculata bear tumors — than to the one of N. rustica, a species included in the same sub-genus and whose hybrids with N. paniculata never bear tumors. These studies are still in progress.