Introduction of wild germplasm in modern roses

Introduction of germplasm from wild species is a prerequisite for the enlargement of the relatively small gene pool in roses. In the present study testcrosses between different European wild species and selected tetraploid cultivated roses were made to evaluate crossing efficiencies. Significant differences were observed among the tested combinations. Interspecific crosses frequently generate F1 plants with odd chromosome numbers (mostly triploids). These triploids produce both monoploid and diploid pollen fractions. Pollen sorting could increase the percentage of diploid pollen before it is used for pollination. To evaluate the genetic transfer between wild and cultivated roses a protocol for making DNA microsatellites profiles of a single pollen was developed.