Potentials in Prunus mahaleb L. for cherry rootstock breeding

• Increasing interest in variability and breeding of Prunus mahaleb L. as cherry rootstock.
• Compiled information on rootstock usage and important traits of mahaleb cherry.
• Extended vigor range by seedlings of self-fertile seed trees and clonal mahalebs.
• Interspecific hybrids of mahaleb crossed with dwarfing species and hybrids.
• Valuable site tolerance traits in mahaleb cherry considering the climate change.

Overview on Prunus mahaleb L. rootstock breeding and evaluation compile the knowledge on variability, rootstock traits based on systematic evaluation and results achieved in previous breeding projects. Conclusion is that adaptability of mahaleb cherry to continental climate, tolerance to drought, hot summer, poor soils, high pH and lime tolerance are valuable rootstock traits considering the forecasted environmental conditions due to the climate changes. The diverse rootstock usage in vigor control is the present situation in the sweet and sour cherry growing. This diverse rootstock usage might be continued for the future too, when training system and rootstock are considered together, matched properly with the vigor of orchard site. There are few clonal rootstocks showing vigor 65–70% compared to seedlings with medium precocity. Further on the potential in compact or spur type mahalebs, genetic dwarf genotypes or inbred lines are still not fully utilized in mahaleb cherry breeding. Possible interspecific crosses between P. mahaleb and other cherry species (Prunus avium and Prunus fruticosa crosses are known yet) also could extend the range of desired growth control and precocity. Traditional seed tree selection resulted in seed tree clone, producing high quality seedlings for sweet- and sour cherry growing but their vigor control and precocity does not meet all the requirements of modern pedestrian orchards. Variability of mahaleb cherry manifested in selected genotypes, inbred lines and potential of interspecific crosses promise progress in those directions that are desired rootstock traits in vigor control, precocity and environmental adaptability.