Seawater resistance in sweet potato (Ipomoea batatas) seeds: a key factor for natural dispersal from the Americas to Oceania
- Author(s): Andrade Pereira, Débora;
- Ferreira Nunes, Hendrie;
- Ruiz Pessenda, Luiz C.;
- Oliveira, Giancarlo C. X.
- et al.
Published Web Locationhttps://doi.org/10.21425/F5FBG46169
Sweet potato dispersal from Americas to French Polynesia predates known human colonization periods, therefore being a long-standing dilemma. According to recent phylogenetic studies, the most likely hypothesis to explain this migration is the sea-drift long-distance dispersal, but no research indicating the response of I. batatas seeds to seawater conditions have been performed so far. The aim of this study was to understand seawater resistance in I. batatas, an essential feature for the sea-drift natural dispersal hypothesis, thus shedding light on the historical biogeography of this species, which also has implications on human civilization history, as the archaeological presence of sweet potato in both continents has been used as an evidence of pre-Columbian contacts between ancient civilizations. The experiment consisted of submitting sweet potato seeds to seawater treatments and observing the respective germination rates after different periods of immersion. Subsequently, one-way ANOVAs were conducted to test for significant differences between groups. All seeds from the seawater immersion treatments germinated, which confirms that I. batatas seeds are resistant to seawater salinity for a period of 120 days. Our results support the sea-drift natural dispersal hypothesis, thus shedding light on part of the logical conditions for one of the major hypotheses on the historical biogeography of this species, which also plays an important role in the discussions related to prehistorical human mobility in Polynesian islands.