The use of a candidate gene approach to arrive at botrytis resistance in gerbera

Gerbera grey mould (Botrytis cinerea) causes substantial loßes in quality and quantity during gerbera production and postharvest transportation. Developing cultivars with resistance to Botrytis is therefore an important goal for gerbera breeding. In this study, we employed a candidate-gene (CG) approach to map potential candidate genes for Botrytis resistance and screened those genes for colocalisation with quantitative trait loci (QTL) regions, which were mapped in two segregating populations. For example, the selected candidate gene 2-pyrone synthase (2-PS) codes for polyketide synthase which synthesises a putative precursor for two phytoalexins in gerbera. Using our recently developed transcriptome resource for the parents of mapping population, 2-PS gene sequence variation was found and employed as single nucleotide polymorphism (SNPs) markers. Segregation results in the population showed that the 2-PS gene may indeed be aßociated with Botrytis resistance. The SNP markers for the 2-PS gene can be used to improve Botrytis resistance in gerbera by selecting for the favourable alleles of the 2-PS gene in marker-Aßisted selection.