Synteny-Based Development of CAPS Markers Linked to the Sweet kernel LOCUS, Controlling Amygdalin Accumulation in Almond (Prunus dulcis (Mill.) D.A.Webb).

The bitterness and toxicity of wild-type seeds of is due to the cyanogenic glucoside amygdalin. In cultivated almond ( (Mill.) D.A. Webb), a dominant mutation at the locus prevents amygdalin accumulation and thus results in edible sweet kernels. Here, we exploited sequence similarity and synteny between the genomes of almond and peach ( (L.) Batsch) to identify cleaved amplified polymorphic sequence (CAPS) molecular markers linked to the locus. A segregant F₁ population was used to map these markers on the genomic region, together with -linked simple sequence repeat (SSR) markers previously described. Molecular fingerprinting of a cultivar collection indicated the possibility to use CAPS polymorphisms identified in this study in breeding programs arising from different parental combinations. Overall, we highlight a set of codominant markers useful for early selection of sweet kernel genotypes, an aspect of primary importance in almond breeding. In addition, by showing collinearity between the physical map of peach and the genetic map of almond with respect to the genomic region, we provide valuable information for further marker development and positional cloning.