Several investigators compiled comprehensive lists of Nicotiana hybrids. The earliest modern inventory was that by East (1928) who listed 65 interspecific combinations. It was followed by the list published by Kostoff (1943) who reported on 181 hybrids known to him. The last complete lists of interspecific Nicotiana hybrids with references were published by Goodspeed (1945, 1954). In the latter publication, the references to particular hybrids were scattered among the entries of the book’s subject index. Together with several new combinations added a few years later (Goodspeed and Thompson, 1959) the number of documented interspecific hybrids stood at 243. The numbers of Nicotiana hybrids that were communicated later (Smith, 1968, 300 hybrids) and Apparao and Ramavarma (1974, 340 hybrids) were not supported by references to particular hybrid combinations. For the lack of more accurate data those estimations, although long outdated, have been non-the-less frequently quoted up to the present time. As more than 70 years have elapsed since Goodspeed’s last inventory, the author of this volume thought it advisable to prepare a long-overdue update. Although the list below obviously exceeds the topical delimitations of this volume, annexing this updated inventory to a regular monograph on a closely related subject seems to be a good practical solution since publishing self-contained lists of this kind is not an accepted custom. The list also serves as an extension to the last column of Table 7.1.

Table 7.1 Interspecific hybrids within the genus Nicotiana reported by the year 2023
Full size table

In all probability, the list is not complete. It drew mostly on reports that were accessible through the web. The author faced the same problem as he did while working on other parts of this review: difficulty in searching materials published in remote parts of the globe or in exotic languages or/and scripts. Conversely, many of the listed hybrids have been repeatedly reported in many publications. Regardless of reporting frequency, only the first reports, a maximum of seven, were cited for each hybrid combination.

In earlier reports, hybrids that failed to reach the blooming stage did not qualify as successful hybrids and usually were listed separately. The list in this volume was extended by adding two, possibly debatable, categories:

  1. 1.

    five reports on the intrasectional hybrids with N. rastroensis – the hybrids did not develop beyond the seed stage and seeds were not sown. The author assumes that in this particular case successful fertilization and viable seeds may substitute for an actual living hybrid plant since there has been no report on post-zygotic crossability barriers between 9-chromosome species of the section Alatae;

  2. 2.

    reporting on 12 lethal hybrids that may have not actually been grown past the seedling stage. The argument is that those hybrids mostly belong to lethality type II, the crossability barrier that has been repeatedly demonstrated to be removable by tissue culture and, more recently, by chemical treatment and genetic engineering. Those two categories put aside, the inventory still includes 434 viable hybrid combinations including a few that may have not grown to full maturity.