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

Abstract

The bitterness and toxicity of wild-type seeds of Prunoideae is due to the cyanogenic glucoside amygdalin. In cultivated almond (Prunus dulcis (Mill.) D.A. Webb), a dominant mutation at the Sk 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 (Prunus persica (L.) Batsch) to identify cleaved amplified polymorphic sequence (CAPS) molecular markers linked to the Sk locus. A segregant F1 population was used to map these markers on the Sk genomic region, together with Sk-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 Sk genomic region, we provide valuable information for further marker development and Sk positional cloning.

Construction of a highly saturated linkage map in Japanese plum (Prunus salicina L.) using GBS for SNP marker calling

“…Conserved synteny is important to plant breeding because it can be exploited to identify molecular markers linked to agronomically relevant traits between related species. A recent example of synteny-based development of molecular markers was done between peach and almond [62]. Therefore, based on the synteny pattern observed between Prunus species we tried to identify SNPs mapped in Japanese plum in genes localized in the V2.1 peach genome.…”

Chemical Markers to Distinguish the Homo- and Heterozygous Bitter Genotype in Sweet Almond Kernels

“…With this scope, a classification of the genitor cultivars into homozygous or heterozygous for the sweet character is necessary. At present, the genotype of almond cultivars and selections is deduced after crossing by recording the phenotype of their descendants through kernel tasting, and quantifying the seedlings with sweet and bitter kernel [ 12 , 20 ], because molecular markers are not well developed yet to be useful [ 17 , 21 ]. This implies a long waiting time until cropping (3–4 years).…”