Genetic diversity and structure of three Andean tubers: Oxalis tuberosa Molina, Ullucus tuberosus Caldas and Tropaeolum tuberosum Ruiz & Pav.

Malice, M. 2009. Genetic diversity and structure of three Andean tubers: Oxalis tuberosa Molina, Ullucus tuberosus Caldas and Tropaeolum tuberosum Ruiz & Pav. Doctoral thesis. Université de Liège. 185 p.

: Andean tubers oca (Oxalis tuberosa Molina), ulluco (Ullucus tuberosus Caldas) and mashua (Tropaeolum tuberosum Ruiz & Pav.) are cultivated tuber-bearing species originating from the high Andes, where they play a major role at the food, agronomic, cultural and economic levels. Genetic diversity within these species is very large but is threatened with genetic erosion. In this context, we studied samples of oca, ulluco and mashua, maintained in in situ and ex situ conservation systems in Peru and Bolivia, with the objective to contribute to the effective conservation (in situ and ex situ) of these neglected species. This study combined Andean indigenous knowledge, agronomic, morphological and molecular data. We showed that Andean agriculture preserves high diversity, at the inter-specific level but also at the intra-specific one, in terms of number of local varieties. We also pointed out the presence of heterogeneous varieties, the congruence between molecular and morphological data, and a genetic structure influenced by the geographical provenance. Finally, we summarized our observations in a recapitulative model. We enlightened the importance of intrinsic characteristics of the species (reproductive characteristics) as well as specificities of the Andean agricultural system (sociocultural, economic and environmental factors). This study has contributed significantly to the understanding of the genetic diversity and structure of Andean tubers.