Dealing with AFLP genotyping errors to reveal genetic structure in Plukenetia volubilis (Euphorbiaceae) in the Peruvian Amazon

PLoS One. 2017 Sep 14;12(9):e0184259. doi: 10.1371/journal.pone.0184259. eCollection 2017.

Abstract

An analysis of the population structure and genetic diversity for any organism often depends on one or more molecular marker techniques. Nonetheless, these techniques are not absolutely reliable because of various sources of errors arising during the genotyping process. Thus, a complex analysis of genotyping error was carried out with the AFLP method in 169 samples of the oil seed plant Plukenetia volubilis L. from small isolated subpopulations in the Peruvian Amazon. Samples were collected in nine localities from the region of San Martin. Analysis was done in eight datasets with a genotyping error from 0 to 5%. Using eleven primer combinations, 102 to 275 markers were obtained according to the dataset. It was found that it is only possible to obtain the most reliable and robust results through a multiple-level filtering process. Genotyping error and software set up influence both the estimation of population structure and genetic diversity, where in our case population number (K) varied between 2-9 depending on the dataset and statistical method used. Surprisingly, discrepancies in K number were caused more by statistical approaches than by genotyping errors themselves. However, for estimation of genetic diversity, the degree of genotyping error was critical because descriptive parameters (He, FST, PLP 5%) varied substantially (by at least 25%). Due to low gene flow, P. volubilis mostly consists of small isolated subpopulations (ΦPT = 0.252-0.323) with some degree of admixture given by socio-economic connectivity among the sites; a direct link between the genetic and geographic distances was not confirmed. The study illustrates the successful application of AFLP to infer genetic structure in non-model plants.

MeSH terms

  • Amplified Fragment Length Polymorphism Analysis*
  • Euphorbiaceae / genetics*
  • Genotyping Techniques*
  • Peru

Grants and funding

This research was supported financially by an Internal Grant Agency of the University of Life Science Prague CIGA Project No. 20144207, by the Internal Grant Agency of Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague IGA Project No. 20165014, by The Talent Foundation of Josef, Marie and Zdeňka Hlávkových and Scholarship (“Nadání Josefa, Marie a Zdeňky Hlávkových”) provided on base of Bilateral Agreement between CULS Prague and UNU in Pucallpa and by the Ministry of Agriculture of the Czech Republic (no. RO0415). We would like to thank Lucas Garcia Chujutalli for his cooperation in samples collection and Dr. Martina Melounová for help with scientific English terms and vocabulary.