Selection of pollinators for particular pear cultivars (Pyrus communis L.) based on the observation of the pollen tubes

S u m m a r y Most fruit-tree species, including pear (Pyrus) have genetically controlled ability to outcrossing (self-incompatibility). From the orchard practice point of view outcrossing is desired for obtaining acceptable yield level. So, the aim of the present study was to learn problem of self-incompatibility or cross-compatibility of six pear (P. communis) cultivars (Amfora, Radana, Red Williams, Carola, Conference, Dicolor) and wild ecotype of P. pyraster and the evaluation of investigated cultivars as good polinators for each other. The mode of pollination consists of intracultivar self- and cross-pollination and intercultivar diallel cross-pollination. The pollination was done in three different environmental conditions i.e. orchard, glasshouse and laboratory. Self-incompatibility or cross-compatibility of investigated cultivars was evaluated on the base of the pollen germination index (PGI). Six cultivars of pear and one ecotype of wild pear which were under investigation showed full self-incompatibility. In some inter-cultivar and interspecific pollinations full cross-incompatibility or unilateral incompatibility was observed.