Distribution of oca (Oxalis tuberosa; Oxalidaceae) diversity in Pisac, Peru, with respect to folk classification, morphology, and microsatellites

Traditional crop diversity is vital to both agroecosystem sustainability and human health, and knowledge about varietal distribution and appropriate diversity metrics can strengthen efforts to preserve this biocultural resource. We use a case study of the Andean tuber crop oca (Oxalis tuberosa; Oxalidaceae) in Pisac District, Cusco, Peru, to assess household and community predictors of oca diversity, with diversity measured in terms of folk cultivars, morphotypes, and microsatellite-based genotypes.  Results confirm expectations and informal observations that oca diversity is richest in more isolated communities and that rare varieties are most often conserved by elders.  We evaluate opportunities and challenges associated with each diversity metric at this spatial scale, with special emphasis on traditional knowledge, phenotypic plasticity, and cost efficiency. Finally, we discuss the implications of our findings on both in situ and ex situ conservation efforts.