Jeremy recently mused about the possibility of reconstructing the cultivated peanut. As coincidence would have it, a brace of papers just out look at the same thing for a couple of other crops.
A team from the US, Canada and Turkey describe in Euphytica how they reconstructed the modern cultivated dessert strawberry (Fragaria x ananassa) by crossing F. virginiana and F. chiloensis. That’s what happened in the 18th century in some gardens in Britanny once the Chilean strawberry, cultivated for a thousand years by the Mapuche, found its way there after its introduction to Europe by the French spy, Captain Amédée-François Frézier, and met the wild Virginia strawberry. That had started replacing the local cultivated F. vesca in European gardens up to a century before. The researchers were able to come up with significantly better varieties of dessert strawberry by being careful to choose a wider range of elite, complementary genotypes as parents.
And over at GRACE, Iranian and Japanese researchers looked for areas where cultivated tetraploid (durum) wheat is found together with the other putative parent of bread wheat, i.e. wild/weedy Aegilops tauschii. They found the two species in close proximity in two districts in the central Alborz Mountains. So, the “association hypothesized in the theory of bread wheat evolution staill exists in the area where bread wheat probably originated.” The paper does not report finding any natural hybrids, but it does suggest that further field studies should be undertaken, presumably to look for evidence of such introgression.
Although I’m pleased to see the work being done to re-synthesize F. x ananassa from F. chiloensis and F. virginiana, mostly just because I think it’s cool, it’s really a pretty academic exercise, because both species hybridize freely with ananassa (though surprisingly little has actually been done). I’m not really sure what crossing F. virginiana and F. chiloensis would accomplish in terms of practical breeding that crossing elite clones of either with F. x ananassa wouldn’t. (Which is not to say it isn’t useful in terms of developing a better understanding of the genetics of the crop).
It’s interesting to look at the different breeding programs around the world and see how more or less the same pool of founding genetics has in some ways been selected back towards the original species, with the northeastern U.S. cultivars showing more resemblance to F. virginiana, and the California varieties showing more similarity to F. chiloensis. (Those are my superficial observations, not any kind of systematic measurement, though).
To me, a much more interesting (and challenging) task, and one perhaps more analogous to the peanut situation, would be synthesizing the octoploid species from the diploids. Strawberries are more complicated alloploids than peanuts, with a genome composition of AAA’A’BBB’B’. Both virginiana and chiloensis appear to have the same composition, suggesting a fairly recent common ancestor. What the diploid progenitors of the octoploid species were has long been a matter of debate. F. vesca has long been considered a top candidate for the A genome, and a rare Asian species, F. iinumae, has been suggested for the B genome. The others are not as clear. F. mandshurica (which only sort of has official species standing) has been suggested as an A’ donor. I kind of suspect that both B and B’ may be derived from iinumae, with the differences accumulated over millenia of diploidization.
Synthesizing an octoploid with a compatible genome composition to ananassa from the diploids WOULD have significant promise for breeding, by giving breeders access to a wider range of genetics than currently available. Octoploids have been synthesized before, but not with compatible genomic compositions, in part because nobody has yet managed to cross iinumae with much of anything–another parallel with the peanut situation. (To my knowledge, though, no one has even managed to generate sterile hybrids that could be doubled with colchicine to restore fertility).