STUDY OF RESISTANCE ALLELES TO SHARKA (Plum Pox) IN APRICOT (Prunus armeniaca L.) GENOTYPES SPREAD IN AZERBAIJAN

Apricot (Prunus armeniaca L.) is an important fruit plant in Azerbaijan. Plum pox virus is the most important viral disease of pome fruits. Sharka disease caused by Plum pox virus (PPV) reported in over 40 countries, is an important global threat to stone fruits production including apricot (Prunus armeniaca). Important progress has recently been made in apricot (Prunus armeniaca), identifying a major locus on chromosome 1 that explains much of the variation in the resistance trait of plum pox virus (PPV). A major PPV persistence locus (PPVres) of ~ 196 kb in apricot (Prunus armeniaca L.) was mapped upstream of linkage group 1. A number of resistance-related molecular markers have been developed and validated in different genetic backgrounds, confirming their application for breeding purposes. Marker-assisted selection (MAS) has great potential to improve the efficiency of conventional breeding, especially for complex traits such as PPV resistance, which require long and expensive phenotyping procedures. Four SSR markers (PGS1.21, PGS1.23 and PGS1.24) located on LG1 close to the PPVres locus and the ZP002 marker were studied. These three (PGS1.21, PGS1.23 and PGS1.24) SSR markers and the ZP002 marker have been reported to have resistance-associated alleles. The cultivars "Harlayne" and "SEO" harboring resistance-related alleles were also used as controls for the search for resistance alleles in the population. In 3, 15, 15 and 9, respectively, cultivars and forms contained three SSRs (PGS1.21-240, PGS1.23 -161, PGS1.24-119) and one SSLP locus (ZP002-127) (SEO)/Harlayne-type resistance alleles were detected. Of the 61 apricot genotypes, 28 had at least one resistance allele. In linkage group 1, nine unique allelic variants of the ZP002 loci associated with the major PPV resistance locus were identified. The results show that Azerbaijani apricots are an important source for breeding PPV-resistant apricots.