RosBREED: Functional Allele Distribution for Blush Development in U.S. Peach Breeding Germplasm
RosBREED: Functional Allele Distribution for Blush Development in U.S. Peach Breeding Germplasm
Wednesday, July 24, 2013
Desert Ballroom: Salons 7-8 (Desert Springs J.W Marriott Resort )
Skin blush is an important trait for marketing peaches. The red skin pigmentation develops through the flavonoid and anthocyanin pathways, and both genetic and environmental stimuli, and their interaction, control the regulation of these pathways. Blush is under polygenic control with one major QTL locus and several minor QTL loci throughout the genome. A study of one major QTL locus, Blush.Pp.ZC-3.1, associated with blush in peach discerned functional alleles/haplotypes with high/low probability of producing high/low blush phenotypes. The U.S. Prunus germplasm under the RosBREED collaborative effort was phenotyped in 2011 and 2012 for the percentage of blush covering the fruit skin using a scale from 0–5; 0 indicating no blush and 5 indicating full red surface color. High resolution genome scanning of RosBREED material provided necessary DNA information for determining distribution of high/low blush functional alleles/haplotypes in breeding germplasm. Four functional alleles defined as ‘a’, ‘b’, ‘c’, and ‘d’ were detected at trait loci for high/low blush in U.S. breeding germplasm. Functional allele ‘c’ (i.e., c/c, c/b, c/a) was associated with significantly higher blush (> 50 % P < 0.001: *Tukey-Kramer HSD) while functional allele ‘d’ when homozygous exhibited significantly lower blush (< 10%; P < 0.001; *Tukey-Kramer HSD). In this presentation, functional alleles and functional genotypes of U.S. peach breeding germplasm will be revealed and possibility for marker assisted parent and seedling selection discussed.