Genetic structure and molecular divergence among samples of mandacaru (Cereus spp.; Cactaceae) as revealed by microsatellite markers

• Microsatellite transferability was used to differentiate samples of the mandacaru.
• Microsatellite transferability was 30.3% in mandacaru from four regions of Brazil.
• A total of 31 alleles, with an average of 2.58 alleles per locus, were detected.
• High genetic divergence among samples from four Brazilian regions was detected.
• Molecular divergence at SSR loci indicated threes species for the mandacaru samples.

Microsatellite transferability was used as a method to differentiate samples of mandacaru cultivated in the South (S), Southeast (SE), Northeast (NE) and Midwest (MW) regions of Brazil. Ten microsatellite primers designed from Polaskia chichipe (Pchi5, Pchi21, Pchi44 and Pchi47), Ariocarpus bravoanus (mAbR05, mAbR28 and mAbR86), Astrophytum asterias (AaB6 and AaD9), and Echinocactus grusonii (mEgR78) were polymorphic. A total of 31 alleles, which makes an average of 2.58 alleles per locus, were detected in mandacaru plants. The analyzed mandacaru cacti from the NE region presented lower polymorphism than their relatives from S, SE, and MW regions. The AMOVA showed a higher genetic variation among than within the analyzed samples. Clustering of the samples determined via Bayesian analysis indicated that the 112 analyzed mandacaru plants were grouped into 3 subpopulations. The highest proportion of plants from the S/SE (80.3%/77.5%), NE (91.5%), and MW (95%) were observed within blue, red, and green groups respectively: the mandacaru cacti form genetically structured populations. Molecular divergence at the SSR loci indicated three species: one species located in the South (S) and Southeast (SE) regions, another species in the Northeast (NE) region, and a third one in the Midwest (MW) region of Brazil.