SELECTION AND IMPROVEMENT OF DATURA-INNOXIA MILL - MORPHOLOGICAL VARIABILITY IN INVITRO PROPAGATED PLANTS

To select high-alkaloid-producing plants, we have developed an experimental model producing the largest possible number of plants differing from the source plant. On the basis of the commonly accepted idea that the formation of an intermediate callus would increase chances of recovering altered plants, we propagated Datura innoxia Mill. through axillary buds (micropropagation) and through regeneration from explants giving a callus at various degrees of development before bud shoots are differenciated. Seventy-eight plants were obtained; their morphological characteristics were observed at the first floral bud stage. Numerous plants, including those propagated through axillary buds, were smaller and had less leaves than seed-grown plants. Very peculiar features (flowers, leaves, ramifications) were observed in five plants ("abnormal plants"): two were produced from thin cell layers without intermediate callus, three from internodes after formation of a well-developed intermediate callus. No "abnormal plant" of this sort was observed among plants derived from stem discs in spite occasionally of the formation of an intermediate callus. These results clearly show that regeneration of plants morphologically different from seed-grown is not dependent on the development of an intermediate callus.