Sterile Amphidiploids: Their Possible Relation to the Origin of Nicotiana tabacum

Heterochrony and its role in sex determination of cryptically dioecious Consolea (Cactaceae) staminate flowers

“…In these plants, when ovule abortion occurs, a wide range of ovule and ES anomalies are displayed (Bradbury, 1929;Harrold, 1935;Arnason, 1943;Rick, 1946;Hartman & Howlett, 1954;Wilms et al, 1983;Alburquerque, Burgos & Egea, 2002;Rosellini et al, 2003). Amongst hybrids, female sterility is commonly the result of arrested ES development, either at meiosis or during mitotic divisions of the megaspore (Greenleaf, 1941;Carapetian & Rupert, 1989;Liu, Xu & Zhang, 2004). Partial female sterility in economically important crop species ranges from failure to form an ES, arrested ES development, and consequently immature ESs at anthesis, to degenerated ESs at anthesis (Bradbury, 1929;Harrold, 1935;Arnason, 1943;Rick, 1946;Hartman & Howlett, 1954;Wilms et al, 1983;Alburquerque et al, 2002;Rosellini et al, 2003).…”

Evidence on Rates of Evolution from the Distribution of Existing and Fossil Plant Species

“…And the origin of some of these allopolyploids, such as Qaleopsis Tetrahit (Muntzing 1931), Nicotiana tabacum (Goodspeed and Clausen 1928;Greenleaf 1941), and Triticum aestivum (McFadden and Sears 1946), as been demonstrated by the artificial synthesis of the species or a closely related form. And in certain instances cytogenetic evidence has greatly aided such inferences.…”

“…It is now a well established fact that a large proportion of species of the higher plants have originated through allopolyploidy, that is through hybridization between two preexisting species and consequent doubling of the chromosome number in the sterile hybrid. And the origin of some of these allopolyploids, such as Qaleopsis Tetrahit (Muntzing 1931), Nicotiana tabacum (Goodspeed and Clausen 1928;Greenleaf 1941), and Triticum aestivum (McFadden and Sears 1946), as been demonstrated by the artificial synthesis of the species or a closely related form. And in many other examples the probable parents of a natural allopolyploid have been inferred from strong morphological and cytological evidence.…”

Amphidiploids produced by natural chromosome-doubling in inter-specific hybrids betweenDianthus×isensisHirahataetKitam. andD. japonicusThunb.

“…Therefore, it is necessary to restore fertility by inducing amphidiploidy and by artificial chromosome-doubling through the use of colchicine or other chemicals with mitotic inhibitor activity once a hybrid has been successfully obtained. Successful restoration of fertility by artificial chromosome-doubling has been reported in species such as Lilium (Asano, 1982;Van Tuyl et al, 2000;2002), Cyclamen (Ishizaka and Uematsu, 1994), Iris (Yabuya, 1985), Nicotiana (Greenleaf, 1941) and Arabidopsis (Nasrallah et al, 2000).…”