In Peach (Prunus persica
) several physiological changes, such as woolliness, triggered by
chilling injury are involved in major production losses due to cold storage of the fruits during shipping.
Additionally, the low level of polymorphisms among peach varieties is an important limitation in the
search for new molecular markers that could be associated with economically important traits.
Therefore, a functional approach was employed to associate candidate genes with an informative
marker in peach. The data was obtained from the results of an in silico
analysis of four different cold
peach treatments. Thirty two candidate genes were selected that were aligned against Arabidopsis
genomic sequences to design intron-flanking EST-PCR markers. These markers were used to
position the candidate genes on the Prunus
genetic reference map. In the physiological response to
chilling injury, cell wall integrity, carbohydrate metabolism and stress response pathways could be
involved, therefore candidate genes associated by Gene Ontology annotation to these pathways were
included in the analysis. The designed markers were positioned to the Texas X Earlygold (TxE) genetic
reference map through selective mapping methodology (Bin mapping). 72% of these new markers
showed polymorphism in the TxE Binset population and 31% of them were successfully mapped to a
genetic position on the Prunus
reference map. The bioinformatic methodology used in this work
includes a first approach in search for functional molecular markers associated to differentially
expressed genes under certain physiological condition which in addition to the Bin mapping approach
allows addressing a genetically anchored position to these new markers.