Construction of Tetraploid Rose Maps and Analysis of Segregation Type

Polyploidy is common in many important crop plants and especially in ornamentals. In polyploids more than two different alleles may occur per locus in one plant, while any given allele may exist in the plant in multiple ‘dosages’. This puts constrains on genetic analyses in polyploids. To resolve these constrains one can start with constructing separate maps for each haplogroup, but this means that many hundreds to thousands of markers are needed to construct genetic maps. Such high numbers of SNP markers can nowadays be identified using next generation sequencing, and genotyped on SNP arrays.

We developed a 68k SNP Axiom array (WagRhSNP) for rose based on transcriptome data and used them to genotype tetraploid garden and cut rose F1 populations. SNPs were scored using software for dosage scoring (fitTetra, Voorrips et al., BMC Bioinform 12:172, 2011). Results of mapping, synteny of the maps to Fragaria, and analyses of the segregation type of rose (random vs preferential pairing) will be presented.