Identification of S-alleles in some indigenous sweet cherry genotypes grown in Ohrid region

Abstract

Sweet cherry (Prunus avium L.) is one of the major fruit species grown in the Ohrid region. The assortment is primarily based on the indigenous genotype of ʻOhridska Dolga Šiškaʼ, which is characterized by very useful biological and agronomic properties that provide high economic value, and which is surrounded with sporadic trees from the other local genotypes for which the growers believe that they are good pollenizers. As the origin of these old genotypes is uncertain, and cases of homonyms or synonyms might occur, a reliable identification is required. Since sweet cherry exhibits gametophytic self-incompatibility, controlled by the multi-allelic S-locus that prevents self-fertilisation, determination of S-alleles of indigenous genotypes is an important step in molecular characterization that is also of enormous significance for growers and breeders to choose appropriate pollenizers in the orchard aiming to the efficient production of fruits and planning crosses in developing new cultivars. The paper presents the results of identification of S-alleles and incompatibility group in eight Macedonian indigenous sweet cherry genotypes [four genotypes of ʻOhridska Dolga Šiškaʼ (ODŠ), two genotypes of ʻOhridska Crvena Krckaʼ (OCK), ʻOhridska Brzaʼ and ʻOhridska Crnaʼ] collected in the Ohrid region. The use of the polymerase chain reaction (PCR) with consensus primers for the second introns (PaConsII-F and PaConsII-R) of S-RNase and allele-specific primers revealed the following S-allelic constitutions in the assessed genotypes: S2S4 (ʻOCK-1ʼ), S3S9 (ʻOhridska Brzaʼ), S3S12 (ʻODŠ-O1ʼ, ʻODŠ-O2ʼ, ʻODŠ-S1ʼ and ʻODŠ-S2ʼ) and S4Sx (ʻOCK-2ʼ and ʻOhridska Crnaʼ). Based on the obtained S-allelic constitutions, the assessed genotypes have been assigned to incompatibility groups XIII, XVI and XXII.