Morillo E., Second Gérard. (2017). Tracing the domestication of the Andean root crop arracacha (Arracacia xanthorrhiza Bancr.) : a molecular survey confirms the selection of a wild form apt to asexual reproduction. Plant Genetic Resources-Characterization and Utilization, 15 (5), p. 380-387. ISSN 1479-2621.
Titre du document
Tracing the domestication of the Andean root crop arracacha (Arracacia xanthorrhiza Bancr.) : a molecular survey confirms the selection of a wild form apt to asexual reproduction
Plant Genetic Resources-Characterization and Utilization, 2017,
15 (5), p. 380-387 ISSN 1479-2621
Andean arracacha (Arracacia xanthorrhiza Bancr.) is a valuable but poorly known vegetatively reproduced root crop whose origin is still unresolved. Wild tuberous forms are present in the presumed areas of domestication and have a perennial or monocarpic life history. To elucidate the origin of the cultivated form, we surveyed a molecular analysis with amplified fragment length polymorphisms (AFLPs) in a representative sample of this crop and its wild relatives from Ecuador and Peru, the presumed areas of domestication. Wild species with tuberous and non-tuberous roots were included, as well as the perennial and monocarpic forms of the presumed wild ancestor. While the two wild varieties of A. xanthorrhiza were closest to the cultivars, they were distinguished by AFLPs. Unexpectedly, two clearly distinct groups were formed among the cultivars, one of which was significantly closer to the monocarpic wild form. However, the chloroplast DNA survey revealed greater similarity between all of the cultivars and the wild perennial A. xanthorrhiza. These results combined with the morphological and life history features, confirms the hypothesis that arracacha domestication started from the wild perennial form. We suggest this scenario of domestication followed by an unsuspected introgression in the cultivation, resulting in two cryptic genetic groups, well distinguished at the molecular level. This is an important revelation with implications in genetic resource conservation and breeding standpoints in this promissory crop.
