Discrimination of almond self compatible genotypes by different methods in a breeding program in Iran

Abstract

Self-incompatibility is one of the most important difficulties in almond production, which reduces fruit set dramatically and makes orchard management difficult. Therefore, producing breeding self-compatible almond genotypes is of great importance. In this research work, the growth of pollen tube was studied in 38 genotypes obtained after crossing “Touno” (male parent) with “Shahrood 12” (female parent). To study fruit set during years 2009 and 2010, four branches of each genotype were bagged in stage D. Results showed that some genotypes were self- compatible. On the other hand, cross-pollination increased the fruit set of self-compatible genotypes. For microscopic study, flowers were harvested at 24, 72 and 120 h after hand pollination. Results of two years (2009 and 2010) study indicated that 24 and 72 h were not enough for the pollen tube to reach the base of style, whereas 120 h were an appropriate time. To double check the status of self-compatible those genotypes and to determinate the situation of genotypes recognized as doubtful by the use of fluorescent microscopy, PCR reaction was carried out with specific primers of SfF and SfR. PCR results confirmed the situation of self-compatible genotypes. In addition, it indicated that five doubtful genotypes were self-compatible. However, another four genotypes were recognized as self-incompatible. In general, 50% of genotypes were realized as self-compatible and another 50% were self-incompatible. Key words: Self compatibility, self-incompatibility, cross compatibility, self pollination, fruit set, fluorescent microscopy, polymerase chain reaction (PCR).