Introductory Notes

With the recent discoveries of new species, the genus Nicotiana probably ranks the fourth largest in the family Solanaceae. The author of this review has counted 108 taxa which have been generally recognized as or at least have been given the provisional status of a separate species. The modern Nicotianae are indigenous to the two Americas, Australia and Africa. Most of them are part of the local flora but some have spread across the world as ornamentals or even as noxious weeds. Nicotiana tabacum and N. rustica have become domesticated as sources of popular nicotine-based stimulants and N. tabacum is now one of the two non-food cash crops of major importance worldwide. Interspecific hybridization in Nicotiana started in the eighteenth century and has continued until the present time providing scientists and agronomists with an insight into the evolution and genetics of the genus and becoming an important tool to exploit its genetic diversity for the improvement of the cultivated species N. tabacum. The introductory review ends up with the description of the major three types of interspecific hybrids and the list of scientific terms and expressions used in subsequent parts of the book.