The almond, ['Prunus dulcis' (Mill) D.A. Webb syn. 'P. amygdalus' Batsch] is an important nut crop belonging to the family Rosaceae. Almond consumption has shown steady growth during the last decades due to the increased awareness of its excellent flavour, nutritional value and health benefits. The Australian climate provides great potential for growing almonds and the Australian almond breeding program was initiated in 1997 to develop cultivars better suited to growing conditions and to meet market demands. The construction of a genetic linkage map for one of the breeding populations (Nonpareil x Lauranne) was a part of this breeding program. This population comprised 181 individuals, of which 93 were used for map construction and quantitative trait loci (QTL) analysis in this study. Important traits that were investigated included flowering time, flower structures in relation to fruit set and autogamy and shell and kernel traits.

Peach and almond have been considered as model species for the family Rosaceae and other woody plants. Consequently, mapping and characterisation of genes in these species has important implications. High-resolution melting (HRM) analysis is a recent development in the detection of SNPs and other markers, and proved to be an efficient and cost-effective approach. In this study, we aimed to map genes corresponding to known proteins in other species using the HRM approach. Prunus unigenes were searched and compared with known proteins in the public databases. We developed single-nucleotide polymorphism (SNP) markers, polymorphic in a mapping population produced from a cross between the cloned cultivars Nonpareil and Lauranne. A total of 12 SNP-anchored putative genes were genotyped in the population using HRM, and mapped to an existing linkage map. These genes were mapped on six linkage groups, and the predicted proteins were compared to putative orthologs in other species. Amongst those genes, four were abiotic stress-responsive genes, which can provide a starting point for construction of an abiotic resistance map. Two allergy and detoxification related genes, respectively, were also mapped and analysed. Most of the investigated genes had high similarities to sequences from closely related species such as apricot, apple and other eudicots, and these are putatively orthologous. In addition, it was shown that HRM can be an effective means of genotyping populations for the purpose of constructing a linkage map. Our work provides basic genomic information for the 12 genes, which can be used for further genetic and functional studies.