The Evolution of Nicotiana benthamiana and the Suaveolentes
The life-time’s work by Thomas Harper Goodspeed culminated in his classic publication of “THE GENUS NICOTIANA” in 1954. He concluded that the Nicotiana genus originated in a region of Gondwana that was to become South America, and that these ancestral plants diverged into three groups. Some of them traversed Gondwana to Australia before the last continents separated more than 36 million years ago. After reaching Australia, two relatives may have crossed and added their genomes together, rather than their chromosomes pairing. This produced the allopolyploid genomes of the twenty three exclusively Australian Nicotianas, of which N. benthamiana is one. Sequence analysis of these genomes should shed light on their relationships and about what could have occurred.