Micropropagation of Polymnia sonchifolia (Yacon)

Abstract

Yacon [Polymnia sonchifolia (P. edulis)] is a perennial plant belonging to the family Compositae. It is a native of the Andes highland, and is distributed in South America, and more recently, in Oceania. Plants grow from spring to summer and the roots enlarge in the autumn in Japan. Crown buds forming at the boundary between hypocotyl and root sprout in the following spring (Fig. 1). A plant produces several roots with a total weight of 100 to 500 g. Roots have a spindle shape with a size of 15∼30 cm (Fig. 2); the shape of the decussate leaves is ovate at the distal half with a slender blade at the proximal half to the stem (Fig. 3). The yellow flowers are composed of about 16 ray florets and central, many-disked florets which open in summer.