Genetic Diversity and Population Structure in Vicia faba L. Landraces and Wild Related Species Assessed by Nuclear SSRs

PLoS One. 2016 May 11;11(5):e0154801. doi: 10.1371/journal.pone.0154801. eCollection 2016.

Abstract

Faba bean (Vicia faba L.) is a facultative cross-pollinating legume crop with a great importance for food and feed due to its high protein content as well as the important role in soil fertility and nitrogen fixation. In this work we evaluated genetic diversity and population structure of faba bean accessions from the Western Mediterranean basin and wild related species. For that purpose we screened 53 V. faba, 2 V. johannis and 7 V. narbonensis accessions from Portugal, Spain and Morocco with 28 faba bean Single Sequence Repeats (SSR). SSR genotyping showed that the number of alleles detected per locus for the polymorphic markers ranged between 2 and 10, with Polymorphic Information Content (PIC) values between 0.662 and 0.071, and heterozygosity (HO) between 0-0.467. Heterozygosity and inbreeding coefficient levels indicate a higher level of inbreeding in wild related species than in cultivated Vicia. The analysis of molecular variance (AMOVA) showed a superior genetic diversity within accessions than between accessions even from distant regions. These results are in accordance to population structure analysis showing that individuals from the same accession can be genetically more similar to individuals from far away accessions, than from individuals from the same accession. In all three levels of analysis (whole panel of cultivated and wild accessions, cultivated faba bean accessions and Portuguese accessions) no population structure was observed based on geography or climatic factors. Differences between V. narbonensis and V. johannis are undetectable although these wild taxa are clearly distinct from V. faba accessions. Thus, a limited gene flow occurred between cultivated accessions and wild relatives. Contrastingly, the lack of population structure seems to indicate a high degree of gene flow between V. faba accessions, possibly explained by the partially allogamous habit in association with frequent seed exchange/introduction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / genetics*
  • Ecotype*
  • Gene Frequency / genetics
  • Genetic Variation*
  • Genotype
  • Microsatellite Repeats / genetics*
  • Phylogeny
  • Polymorphism, Genetic
  • Population Dynamics
  • Principal Component Analysis
  • Species Specificity
  • Vicia faba / genetics*

Grants and funding

HRO was funded by the “Genomics and Evolutionary Biology” project co-financed by North Portugal Regional Operational Programme 2007/2013 (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). DT was funded by Fundação para a Ciência e Tecnologia, Portugal (FCT) doctoral scholarship (SFRH/BD/93156/2013), Manuela Silva by the FCT Investigator Programme (IF/00834/2014). The research work was financed by the FCT LEAF Unit (UID/AGR/04129/2013). The authors acknowledge the following institutions and individuals for providing seeds: Instituto Nacional de Investigação Agrária e Veterinária (Portugal), Centro de Recursos Fitogenéticos INIA (Spain) and IPK (Germany).