On the Spontaneous Hybrids and their Descendants Found among the Cultivations of Different Species of Tradescantia Part I

1. A few years later after the cultivation had begun with different species of Tradescantia many spontaneous seedlings appeared in the field. When they grew up most of them showed the inter- or intraspecific hybridization between certain two in the stocks. Among them, those having certain characters of T. virginiana including the latter stock gradually disappeared. On the contrary, the descendants which leaned toward T. canaliculata or T. hirsutiflora increasingly dominated in the field year after year, except that a few vigorous ones having hybrid nature between latter two survived. These phenomena show us that these species can hybridize ; however, the parent species have their own well-harmonized components in their protoplast for the existence, consequently the hybrids having certain discordant complements were selected off gradually from the descendants. 2. We have found a few plants which have the mutant characters such as a non-flowering miniature and unisexual plants in the descendants. It is very interesting that there was found no descendant having the chlorophyll deficiencies among those descendants, tho ugh searches have been made. On the contrary, we have plants which give us the seedlings having various deficient characters concerning the chlorophyll formation, since a certain number of the stocks of Tradescantia were brought into our green house in 1945 from Hiroshima. There the albino and the virescent appeared with a comparatively high rate among the seedlings mixed with other deficients such as the nonflowering (H. non), unisexual (male) plants (H. males). 3. Among the S-descendants there appeared various floral colours, blue to purple with nuances, in which the purple (rhodamine purple) was prominent. It is considered now that the latter may have been produced by the influence of certain yet unknown deficiency concerning bluing gene, which concerns the absorption of the mineral elements into the cell, kept in SKBG, and brought into the offspring through the hybridization. 4. The various combinations of the various kinds of the associates in the 2n-sets were observed not only in the different stocks, but also in one and the same anther. The highest number of the quadrivalents in a complement was six, and that of the bivalents also six. The increase of trivalents in a complement was caused by the decrease of the quadrivale nts. The components in an associate join each other with their ends, and the parallel pairing is seldom