Mapping of Botrytis Resistance in Gerbera and Validation of Candidate Genes

Botrytis cinerea infection is one of the main causes for production losses in gerbera production. In order to study the genetics of botrytis resistance in gerbera we have performed a QTL study in two segregating populations using EST-SNP markers. Despite the high chromosome number (n=50) and the intersectional origin that may suggests a possible polyploïdisation event in the past diploid segregation was found. Phenotyping was performed using disease tests aimed at infection speed rather than incidence rate which were focussed on petals and disk flowers (both outside appearance and disk flower bottom rot). Results showed multiple relative small effect QTL loci. For more understanding of the mechanisms of resistance a candidate gene approach was used. Gerbera ESTs homologous to genes involved to botrytis resistance from literature were mapped and genes co-localising to QTLs were further studied in expression pattern and functionality.