Cytogenetic techniques for physical mapping in rose (ROOSCYTOGENOMICS)

Genetic maps and marker-assisted selection are frequently used in breeding programmes. However, making the link between genetic and physical maps, and thus the real position of genes and markers on the chromosomes, is lacking behind. In this project we examined the possibilities to physically localize economically interesting genes, markers and traits in the genome and on the chromosomes of plants. In addition we studied how to integrate physical and genetic maps to be able to better examine important traits (drought resistance, cold tolerance, flower characteristics etc.) and their inheritance? Roses were chosen as study material for this project.

The cytogenetic techniques FISH and tyramide-FISH are already frequently used on important agricultural crops, and are now optimized for woody ornamentals in general and for roses in particular. Different parameters (primer design, chromosome slides, antibody concentrations, probe concentrations, etc.) are evaluated. Our optimized protocol for FISH and tyramide-FISH, was applied to physically localize candidate genes for important traits (e.g. drought resistance) on the chromosomes of Rosa wichurana and the inheritance of these candidate genes was studied on hybrids and polyploids derived from Rosa wichurana. The existing genetic maps for Rose are also integrated with the physical maps using HRM technology.

Due to changing climate conditions and the perpetual high standards for qualitative and sustainable cultivars, the traditional breeding programmes are not sufficient anymore. For important agricultural crops more and more innovative techniques are already used in the breeding. The better understanding of the (cyto)genetic background and inheritance of important traits, such as drought resistance, cold tolerance, … will contribute to more efficient breeding strategies and thus result in better and new breeding material in the future, also for ornamental crops.

The results from this research project lead to the PhD of Ilya Kirov (collaboration with the agricultural university in Moscow, Russia) and to several scientific papers. The technology developed in this project are now being used in several other ILVO research projects.