Studies on the Assignment of Some Romanian Sweet Cherry Cultivars into the S Incompatibility Groups

The knowledge on the S incompatibility alleles in the sweet cherry cultivars created in Romania is of great importance in order to assure their pollination within commercial orchards, and consequently to exploit their yield potential. Therefore, from 2001, an extensive study was initiated with the aim of establishing which of the already known incompatibility groups should be assigned to the new and highly valuable cultivars released in Romania. Based on the ability to set fruits when they were cross-pollinated with as many as possible cultivars having different S alleles combinations, useful information was obtained on their most likely assignment to one of the incompatibility groups. 'Daria' and 'Izverna' are among the Romanian sweet cherry cultivars for which the S alleles present at the locus for pollination incompatibility are almost certain. While the first of these cultivars was found to belong to the incompatibility group X (S6S9), the second one must be considered to belong to the incompatibility group IV (S2S3).