Papers

Peer-reviewed
2 2017

Genetic Structure and Selection of a Core Collection for Long Term Conservation of Avocado in Mexico

FRONTIERS IN PLANT SCIENCE
  • Luis F. Guzman
  • ,
  • Ryoko Machida-Hirano
  • ,
  • Ernesto Borrayo
  • ,
  • Moises Cortes-Cruz
  • ,
  • Maria del Carmen Espindola-Barquera
  • ,
  • Elena Heredia Garcia

Volume
8
Number
243
First page
1
Last page
10
Language
English
Publishing type
Research paper (scientific journal)
DOI
10.3389/fpls.2017.00243
Publisher
FRONTIERS MEDIA SA

Mexico, as the center of origin of avocado (Persea americama Mill.), harbors a wide genetic diversity of this species, whose identification may provide the grounds to not only understand its unique population structure and domestication history, but also inform the efforts aimed at its conservation. Although molecular characterization of cultivated avocado germplasm has been studied by several research groups, this had not been the case in Mexico. In order to elucidate the genetic structure of avocado in Mexico and the sustainable use of its genetic resources, 318 avocado accessions conserved in the germplasm collection in the National Avocado Genebank were analyzed using 28 markers [9 expressed sequence tag-Simple Sequence Repeats (SSRs) and 19 genomic SSRs]. Deviation from Hardy Weinberg Equilibrium and high inter-locus linkage disequilibrium were observed especially in drymifolia, and guatemalensis. Total averages of the observed and expected heterozygosity were 0.59 and 0.75, respectively. Although clear genetic differentiation was not observed among 3 botanical races: americana, drymifolia, and guatemalensis, the analyzed Mexican population can be classified into two groups that correspond to two different ecological regions. We developed a core-collection by K-means clustering method. The selected 36 individuals as core-collection successfully represented more than 80% of total alleles and showed heterozygosity values equal to or higher than those of the original collection, despite its constituting slightly more than 10% of the latter. Accessions selected as members of the core collection have now become candidates to be introduced in cryopreservation implying a minimum loss of genetic diversity and a back-up for existing field collections of such important genetic resources.


Link information
DOI
https://doi.org/10.3389/fpls.2017.00243
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/28286510
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000394700100001&DestApp=WOS_CPL