Brassica napus was synthesized by hybridization between its diploid progenitor species B. rapa and B. oleracea followed by chromosome doubling. Cross with B. rapa as a female parent was only successful. Among three colchicine treatments (0.10, 0.15, and 0.20%), 0.15% gave the highest success (86%) of chromosome doubling in the hybrids (AC; 2n = 19). Synthetic B. napus (AACC, 2n = 38) was identi...

In order to produce triploid plants, 2n female gametes were induced by treating female buds and developing embryo sacs of Populus adenopoda Maxim with high temperature exposure. During megasporogenesis, tests were conducted on the relationship between female gametophyte development and morphological changes of female catkins. In the resulting progeny, 12 triploids were produced, and the highest...

Interspecific or intergeneric hybridization, followed by chromosome doubling, can lead to the formation of new allopolyploid species. Recent studies indicate that allopolyploid formation is associated with genetic and epigenetic changes, although little is known about the type of changes that occur, how rapidly they occur, and the type of sequences involved. To address these matters, we have su...