Cultivated strawberry (Fragaria × ananassa) is a genetically complex allo-octoploid crop with
28 pairs of chromosomes (2n = 8x = 56) for which a genome sequence is not yet available.
The diploid Fragaria vesca is considered the donor species of one of the octoploid subgenomes
and its available genome sequence can be used as a reference for genomic studies.
A wide number of strawberry cultivars are stored in ex situ germplasm collections worldwide
but a number of previous studies have addressed the genetic diversity present within a
limited number of these collections. Here, we report the development and application of two
platforms based on the implementation of Diversity Array Technology (DArT) markers for
high-throughput genotyping in strawberry. The first DArT microarray was used to evaluate
the genetic diversity of 62 strawberry cultivars that represent a wide range of variation
based on phenotype, geographical and temporal origin and pedigrees. A total of 603 DArT
markers were used to evaluate the diversity and structure of the population and their cluster
analyses revealed that these markers were highly efficient in classifying the accessions in
groups based on historical, geographical and pedigree-based cues. The second DArTseq
platform took benefit of the complexity reduction method optimized for strawberry and the
development of next generation sequencing technologies. The strawberry DArTseq was
used to generate a total of 9,386 SNP markers in the previously developed ‘232’ × ‘1392’
mapping population, of which, 4,242 high quality markers were further selected to saturate
this map after several filtering steps. The high-throughput platforms here developed for genotyping
strawberry will facilitate genome-wide characterizations of large accessions sets
and complement other available options.
