Fluorescence microscopy is a relatively rapid and reliable method to determine serf-incompatibility in fruit tree species.It is based on observation of pollen tube growth in the pistils.Pollen tubes stained with fluorochromes show fluorescence when exposed to ultraviolet light.Testing of self-compatibility trait was carried out in 123 apricot cultivars using fluorescence microscopy.In self-compatible cultivars,in the majority of pistils(60-100%),the pollen tubes reached the ovary.