Discovery and characterization of sweetpotato's closest tetraploid relative

In this study, we identified wild autotetraploid plants from Ecuador that are morphologically distinct from Ipomoea batatas and Ipomoea trifida, but monophyletic and sister to Ipomoea batatas in phylogenetic analysis of nuclear data. We describe them as a new species, Ipomoea aequatoriensis T.Wells & P.Munoz. This species is the sweetpotato's closest tetraploid wild relative and likely played a direct role in the origin of sweetpotato's hexaploid genome.