MOLECULAR GENETIC STUDIES ON PEARS (PYRUS SPP.) IN THE WESTERN CAPE

The breeding of pears in South Africa at the Agricultural Research Council has historically been based on the selection of quality traits. However, with the development of molecular markers and genetic maps for pear, it is now possible to implement the use of marker assisted selection (MAS) for pears for both durable resistance and quality trait selection. The focus of our research program has been on the implementation of microsatellite markers, using apple and pear genomic and cDNA sequence data. A number of new markers have been identified and tested. The optimization and multiplexing of the complete set of markers is ongoing for apple and pear, and the current status of the program will be described. In addition, we are exploring two bud mutation systems in the ‘Bon Chretien’ pear, one giving an extreme red colour (‘Bon Rouge') and the other giving lowered chilling requirement (‘Early Bon Chretien’). The genetic mapping and molecular studies of these systems will be summarized.