Preliminary results on effectiveness of marker-assisted seedling selection applied to Mendelian traits in peach
Under the 'FruitBreedomics' project (EU 7th Framework Program), 'pilot studies' were performed in peach to validate the marker-assisted seedling selection (MASS) applied to some Mendelian traits. Therefore, six breeding programs, either private, public or mixed, have phenotyped a total of 7,063 individuals belonging to 68 populations. These segregated either for fruit traits including non-glabrous/glabrous skin (G/g), white/yellow flesh (Y/y), flat/non-flat shape (S*/s*), sub-acid/acid flesh (D/d), and/or the resistance to the green peach aphid (Rm1/rm1). In parallel, leaf samples from each individual were collected and sent to an outsourced genotyping company, for both DNA extraction and genotyping with a set of SNP markers, developed within FruitBreedomics by linkage mapping and genome-wide association analysis, associated to the studied traits. Marker-assisted seedling selection (MASS) effectiveness was then checked by comparing predicted with observed phenotypes. Preliminary results globally show a 'high power' of the markers in predicting the phenotypes, with an average success of 95% for all traits. However, these findings need to be adjusted according to the DNA tests applicability, which varies depending on the available markers, the targeted trait (in particular the Y trait), as well as the parents (genetic backgrounds) used in the different breeding programs studied here. Further data and analyses are still needed to more efficiently use these results.
Mauroux, J.B., Diévart, V., Tuéro, C., Maillard, L., Maillard, A., Aranzana, M.J., Eduardo, I., Batlle, I., Cantin, C., Marcaillou, J.C., Mendoza, O.C., Bassi, D., Pacheco, I., Foschi, S. and Pascal, T. 2017. Preliminary results on effectiveness of marker-assisted seedling selection applied to Mendelian traits in peach. Acta Hort. (ISHS) 1172:425-430
DNA test, fruit, resistance, marker, polymorphism, SNPs-haplotype