Investigation of Variability of Apricot (Prunus armeniaca L.) Using Morphological, Pomological Traits and Microsatellite Markers

Based on 10 (morphological, pomological, phenological) traits and using 10 microsatellite molecular markers, 17 Azerbaijani apricot cultivars and accessions have been evaluated. All the genotypes manifested a high level of variability. Based on the size, fruits were divided into 2 groups: small fruits ( 40 g). Cultivars such as Ordubad eriyi, Ag erik, Mayovka (Terter) and Ag erik Gulnar with fruit weight above 70 g were estimated as very large. In general, fruits had yellow skin ground color and flesh color as well as high TSS. A high correlation was observed between bud break season and blossom season, bud break season and harvest season, bud break season and leaf fall season, blossom season and harvest season, blossom season and leaf fall season, harvest season and leaf fall season. However, a low or insignificant correlation was found between other pomological or phenological characteristics. According to the PCA results, 100% of the total variance among cultivars is attributed to the first seven components. NJ cluster analysis divided apricot cultivars into three main groups. The number of cultivars in the I, II and III clusters were, respectively, eight, seven and two. A total of 60 alleles, ranging from 3 to 9 alleles were revealed by molecular data obtained from microsatellite markers. The average of expected heterozygosity (He), observed heterozygosity (Ho) and polymorphism information content (PIC) were found to be 0.68, 0.77, and 0.63, respectively. The article presents the results of the first genetic diversity analysis of apricot cultivars from the regions. We believe the study will contribute to the effective management and sustainable utilization of apricot germplasm in future breeding programs in the regions

S-Genotype Profiles of Azerbaijan Apricot Germplasm

Apricot is one of the important export products of Azerbaijan. Some studies showed that unproductiveness problem of apricots together with increasing production areas arises because of self-incompatibility. In flowering plants, gametophytic self-incompatibility, controlled by a single locus with several allelic variants, is one of the major problems preventing self-fertilization. Among fruit trees, apricots show a high degree self-incompatibility, especially in Middle-Asian and Iranian-Caucasian eco-geographical groups. In this study, the S-genotypes of a set of 61 Azerbaijan apricot (Prunus armeniaca L.) cultivars were determined by polymerase chain reaction (PCR) amplification of their S-RNase intron regions. In addition, the S-genotyping method was extended to the S haplotype-specific F-box (SFB) gene to detect the non-functional SC-haplotype and hence identification of self-compatible apricot cultivars were carried out by using four primer pairs (SRc-F and SRc-R, EM-PC2consFD and EM-PC3consRD, AprSC8-R and PaConsI-F, AprFBC8-F and AprFBC8-R). A total of 9 S-RNase alleles (S2, S3, S6, S7, S8, S11, S12, S13 and Sc) were determined in the 61 apricot genotypes. As Azerbaijan apricot genotypes are determined to be mostly self-incompatible, the data obtained hereby might be of good use for apricot breeding programs and more practically, for new apricot plantations; thus, pollinator cultivars should be considered when self-incompatible apricot cultivars are being used

Assessment of genetic diversity and search for Plum pox virus resistance alleles of apricot<i> (Prunus</i><i> armeniaca</i> L.) genotypes spread in Azerbaijan using SSR markers

Apricot is one of the most important stone-fruit plants widely cultivated in Azerbaijan. SSR markers were used to evaluate the genetic diversity of 61 apricot genotypes representing the entire gene pool in Azerbaijan. A total of 138 alleles were produced based on 17 SSR markers with an average of 8.1 alleles per primer. The polymorphism information content (PIC) and expected (He) heterozygosity for individual loci were in the range of 0.42-0.8 (mean 0.68) and 0.52-0.82 (mean 0.72), respectively, indicating the abundant genetic variation in Azerbaijani apricot cultivars. The polymorphisms generated by SSRs were enough to differentiate 95% of genotypes, while 4 apricot cultivars exhibited complete similarity between them. NJ tree grouped the 61 genotypes into 7 clusters with 1000 bootstrap values, where the grouping of genotypes was not closely related to the geographic origin or collection site. STRUCTURE analysis identified 4 subpopulations in the collection and, in general, was in agreement with cluster analysis. (SEO)/Harlayne-type resistance alleles of three SSR (PGS1.21-240 bp, PGS1.23-161 bp, PGS1.24-119 bp) and one SSLP loci (ZP002-127 bp) were detected in 3, 15, 15, and 9 accessions, respectively. STRUCTURE analysis could separate genotypes with resistance alleles grouping them in the first two subpopulations. Of the 61 apricot genotypes, 28 had at least one resistance allele. The results demonstrate that Azerbaijani apricots are an important source for breeding PPV-resistant apricots