Genetic variation, population structure and linkage disequilibrium in peach commercial varieties
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Publication date
2010-07-20ISSN
1471-2156
Abstract
Background: Peach [Prunus persica (L.) Batsch] is one of the most economically important fruit crops that, due to its
genetic and biological characteristics (small genome size, taxonomic proximity to other important species and short
juvenile period), has become a model plant in genomic studies of fruit trees. Our aim was an in-depth study of the
extent, distribution and structure of peach genetic variation in North American and European commercial varieties as
well as old Spanish varieties and several founders used in the early USA peach breeding programmes. For this we
genotyped 224 peach cultivars using 50 SSRs evenly distributed along the 8 linkage groups of the Prunus reference
map.
Results: Genetic distance analysis based on SSRs divided the peach cultivars in three main groups based mainly
on their fruit characteristics: melting flesh peaches, melting flesh nectarines and non-melting varieties. Whereas
non-melting flesh peaches had a higher number of alleles than melting peaches and nectarines, they were more
homozygous. With some exceptions (’Admiral Dewey’, ‘Early Crawford’ and ‘Chinese Cling’), the founder US cultivars
clustered together with the commercial melting peaches, indicating that their germplasm is well represented in
modern cultivars. Population structure analysis showed a similar subdivision of the sample into subpopulations.
Linkage disequilibrium (LD) analysis in three unstructured, or barely structured, subpopulations revealed a high
level of LD conservation in peach extending up to 13-15 cM.
Conclusions: Using a much larger set of SSRs, our results confirm previous observations on peach variability and
population structure and provide additional tools for breeding and breeders’ rights enforcement. SSR data are also
used for the estimation of marker mutation rates and allow pedigree inferences, particularly with founder genotypes
of the currently grown cultivars, which are useful to understand the evolution of peach as a crop. Results on LD
conservation can be explained by the self-pollinating nature of peach cultivated germplasm and by a bottleneck that
occurred at the beginning of modern breeding practices. High LD suggests that the development of whole-genome
scanning approaches is suitable for genetic studies of agronomically important traits in peach.
Document Type
Article
Document version
Published version
Language
English
Subject (CDU)
575 - General genetics. General cytogenetics
633 - Field crops and their production
Pages
11
Publisher
BMC
Is part of
BMC Genetics
Citation
Aranzana, Maria José, El-Kadri Abbassi, Werner Howad, and Pere Arús. 2010. “Genetic Variation, Population Structure and Linkage Disequilibrium in Peach Commercial Varieties.” BMC Genomic Data 11 (1): 69. doi: 10.1186/1471-2156-11-69
Grant agreement number
MEC/ /AGL2006-07767/ES/Genetica de asociacion en melocotonero/AGR
MEC/Programa nacional de medios de transporte/CSD2007-00036/ES/Centro de Genómica Básica y de orientación Agroalimentaria/
Program
Genòmica i Biotecnologia
This item appears in the following Collection(s)
- ARTICLES CIENTÍFICS [2805]
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by/4.0/