Diversity of Oxalis tuberosa Molina: a comparison between AFLP and microsatellite markers

Abstract

Traditional crops contribute to food security and agroecological sustainability, but their diversity is increasingly threatened by complex interplays of local and global sociocultural and economic change. Molecular markers are powerful tools to measure and characterize this diversity, and comparisons among different molecular marker systems are necessary to assess their appropriateness in different research contexts. Using a common sample set, we compare amplified fragment length polymorphism (AFLP) and microsatellite (simple sequence repeats; SSRs) techniques to assess their utility in research on the Andean tuber crop oca (Oxalis tuberosa Molina, Oxalidaceae). We find that 26 of 27 individuals have distinct AFLP genotypes, and all 27 individuals have distinct SSR genotypes. Both markers systems cluster samples in agreement with morphotype groups and separate clusters with similar strength, but more variation occurs within AFLP-based clusters than within SSR-based clusters. In addition, correlation between marker systems of pairwise distances is positive and significant (R = 0.831, p = 0.001). Ultimately, we discuss each system’s advantages and disadvantages for future oca diversity research.