EN
This paper reports a study of the alkaloid content of different parts of Datura stramonium L. (Solanaceae) in various stages of its growth and development, and the location, structure and ultrastructure of alkaloid-biosynthesizing cells (idioblasts) in different parts of naturally grown and cultured plant material. TLC, HPLC, and GC/MS methods were used for alkaloid assays. The results showed that alkaloid production starts from the end of the second week after seed germination, increases in different organs up to the tenth week of growth, and then decreases. Leaves and capsules showed the highest alkaloid content in the vegetative and generative stages, respectively. In leaves the alkaloids decreased rapidly in the generative stage. The highest alkaloid content was recorded in vegetative leaves, followed in descending order by vegetative petioles, generative and vegetative stems, generative petioles, generative roots, generative leaves, vegetative roots and mature seeds. The organs as well as calli derived from different leaf parts were examined for the presence of idioblasts by microscopic and cytochemical methods. Idioblasts were present only in semi-hyaline callus originated from leaf base; they were spherical or oval, with a thick cell wall and large central vacuole. These observations should prove helpful in attempts to produce specific alkaloids in naturally grown plants and cell cultures.