Interspecific hybridisation within Buxus spp.

tBreeding efforts within Buxus have been limited, despite the great morphological and genetic variationwithin this genus. To evaluate the possibilities for creating novel cultivars through interspecific hybridisa-tion within Buxus, we have made over 7500 interspecific crosses involving Buxus harlandii Hance, Buxussempervirens L., Buxus microphylla Sieb & Zucc, Buxus balearica Lam., Buxus colchica Pojark and Buxushenryi Mayr. Germination of the resulting interspecific seeds was between 0% and 47% for some crosscombinations. In total 4750 interspecific F1 seedlings were obtained. The hybrid nature of most seedlingscould be proven using AFLP markers or flow cytometry. As expected, crosses at diploid level or tetraploidlevel were efficient. Moreover, our results showed that interploidy crosses (diploid × tetraploid) werealso efficient.This study is the first in-depth exploration of the possibilities of interspecific hybridisation withinBuxus. These results may become a valuable tool to create new Buxus cultivars with desirable traits.