Discrimination of self-compatibility in progenies obtained from crossing between Tono and Shahrood 12 by fluorescent microscopy

Self-incompatibility is one of the most important difficulties in almond production which reduce fruit set dramatically.Therefore, breeding almond to produce self-compatible genotypes is very important. In this research, pollen tube growth was studied in 28 genotypes obtained from crossing between Touno (male parent) and Shahrood 12 (female parent) after self pollination by fluorescent microscopy. Flowers were hand pollinated with their own pollen by brush and then bagged. Flower sample were harvested at 24, 72 and 120 hr after hand pollination. Results showed that 24 and 72 hr were not enough time for pollen tube to reach base of style, but 120 hr was suitable time. At 120 h after pollination according to our classification (percent pistil with pollen tube at the base of style), 60.71% of genotypes were self-incompatible, 17.86% of genotypes were doubtful, 7.14% of genotypes were self-compatible and 14.29% of genotypes were recognized as highly self-compatible. On the other hand, according to another type of classification (mean pollen tube number at the base of style), 50% of genotypes were self-incompatible, 32.14% of genotypes were doubtful and 17.86% of genotypes were recognized as self-compatible. Therefore, pollen tube growth observation by fluorescent microscope has been known a useful and practical method to discriminate self-compatible genotypes when they start to flower.