The potato, brought across the Atlantic by explorers like Christopher Columbus and Francis Drake during the 15th and 16th Centuries, changed Europe forever. During the 18th Century the large, low-maintenance potato harvests eventually provided European working classes with a more reliable food source than they had ever enjoyed. Decades later, arsenic blends to protect potato crops were the first artificial pesticides. Today’s highlighted paper, published in Nature in March, tells us that potato would still be the local speciality of Andean villagers, in spite of those early European explorers, if it weren’t for natural and cultivated variation of a CYCLING DOF FACTOR.
Wild potato is found largely in Bolivia and Peru. There are roughly 180 wild potato species, all of which originated in the Andes and now spread along the west coast of South and Central America, with a few in the southern most states of the USA – all within 40° of latitude from the equator, but with a clear focus between 10° and 20° south (Hijmans and Spooner 2000). These equatorial origins meant the original potatoes brought to Europe had an inherent dependence on short day lengths, and only formed tubers in short autumn and winter days.
Kloosterman et al. compared a wild potato population with a potato population domesticated in Europe. They started out by defining more clearly the ‘potato plant maturity’ QTL on chromosome 5 (Visker et al. 2003), which is associated with onset of tuberization and plant life cycle. They identified a homologue of the A. thaliana CYCLING DOF FACTOR 1 protein which they named StCDF1, which when complete causes potato plants to be late maturing and unable to tuberize in long days. Potatoes with a truncated StCDF1 allele mature early, growing tubers four weeks after planting in long day conditions. (more…)