Investigations of the interspecific hybrid Nicotiana amplexicaulis Burbidge x Nicotiana tabacum L
As a result of crossing maternal Nicotiana amplexicaulis (2n = 36) with N. tabacum (2n = 48) used as the pollen parent, a small number of viable amphihaploid plants were obtained under glasshouse conditions. The survival rate of the amphihaploids was much improved when segregants from the interspecific hybrid N. tabacum x N. glauca were used as the N. tabacum parents and the seedlings were grown under optimum ambient conditions in the growth chamber. The amphihaploids of the latter category showed plant-to-plant variation in chromosome number and morphology. They were self and cross sterile and formed a low number of bivalents in PMC's (from 0 to 8 with the mode of 0). A single amphidiploid plant was obtained by the colchicine treatment of the germinating hybrid seeds. The plant was sterile due to desynapsis at Prophase I.