ABSTRACT
Sweetpotato, Ipomoea batatas (L.) Lam., is a root crop that belongs to the family Convolvulaceae, the morning glory family. It is a creeping dicotyledonous plant and an important crop, widely grown in tropical, subtropical, and warm temperate regions. It ranks as the world’s seventh most important crop, with an estimated annual production of approximately 122 million metric tons (Collado et al. 1999; FAO 2006). On the basis of analysis of morphological characters of sweetpotato and the wild Ipomea species, the center of origin of I. batatas was thought to be somewhere between the Yucatan Peninsula of Mexico and the mouth of the Orinoco River in Venezuela (Austin 1987). Recent evidence revealed by the use of molecular markers suggests that Central America is the primary center of diversity and most likely the center of origin, considering the richness of the wild varieties of sweetpotato (Haung and Sun 2000; CIP 2006). Sweetpotato is especially valued because it is highly adaptable and tolerates high temperatures, low fertility soil, and drought (Yencho et al. 2002).
