Preliminary identification of self-incompatibility genotypes of Sicilian almond landraces

Sicily is the main almond producer in Italy. The almond tree is one of the main protagonists of the Sicilian agrarian landscape, especially in the winter, when the bare branches are covered by white or pinkish flowers. Its presence is particularly significant in the province of Agrigento, in Syracuse and in Ragusa areas, where the almond nut is used for fresh consumption and for the preparation of typical sweets. The extremely rich Sicilian almond germplasm can be useful for genetic improvement, since many local landraces possess aromatic characteristics of the nuts of high value. Self-incompatibility in this species is gametophytic and controlled by a multi-allelic S locus, coding for the stylar RNases and the SFBox protein, expressed in the pollen. In commercial almond orchards, cross-compatible cultivars with overlapping flowering time are usually planted together to ensure fruit set. In this study S-genotypes of Sicilian landraces were investigated for the first time with consensus primers designed for the S locus. Knowledge of the S-genotypes of Sicilian almond germplasm can be helpful for planning pollinators in the orchards and for choosing parents and starting a breeding program focusing on the improvement of local resources.