Strawberry (Fragaria x ananassa Duch.) varieties are susceptible to many fungal diseases. Identification of forms, carrying resistance genes, is an important stage in breeding programs leading to resistant varieties. The use of molecular markers allows to determine with high reliability the presence of the necessary genes in the genome and to identify promising forms. Some of the common strawberry's diseases, causing significant damage to strawberry plantations, are anthracnose (Colletotrichum acutatum Simmonds) and red stele root rot (Phytophthora fragariae var. fragariae Hickman). Dominant Rca2 gene is involved in monogenic resistance to C. acutatum pathogenicity group 2. Rpf1, Rpf2, Rpf3 genes are determined in monogenic resistance to red stele root rot. The purpose of this study was molecular genetic testing genotypes of genus Fragaria L. to identify carriers of Rca2 allele anthracnose resistance and Rpf1 allele red stele root rot resistance. The objects of study were the wild species of the genus Fragaria L. and strawberry varieties (Fragaria x ananassa Duch.) of different ecological and geographic origin. To assess allelic state Rca2 anthracnose resistance gene the dominant SCAR marker STS-Rca2_240 was used, was linked to the resistance gene Rca2 with a genetic distance of 2.8 cM. Rpf1 gene red stele root rot resistance was identified with the dominant SCAR marker R1A, was linked to the resistance gene Rpf1 with a genetic distance of 3.0 cM. The resistant allele of the marker STS-Rca2_240 was identified in the Laetitia variety (Rca2Rca2 or Rca2rca2 genotype), which allows us to recommend it as a promising source in breeding for anthracnose resistance. The other studied forms have homozygous recessive state of the marker STS-Rca2_240 (putative genotype rca2rca2). The resistant allele of the marker SCAR-R1A in the varieties and wild species of strawberry under study is absent, which presumably indicates their homozygous recessive genotype of Rpf1 gene (rpf1rpf1).

Fruit aroma is an important consumer attribute of strawberry varieties. The key volatile compounds of the aromatic complex of strawberry fruit are mesifurane (fruity and caramel aromas) and γ-decalactone (fruity, sweet, or peachy aroma). The mesifurane content in strawberry fruit is controlled by the FaOMT gene, which is mapped to the distal region of the long arm of chromosome VII-F.1. The γ-decalactone content in strawberry fruit is controlled by the FaFAD1 gene, mapped to the distal region of the long arm of chromosome III-2. Identification of forms carrying genes for fruit flavor volatiles is an important step in breeding varieties with fragrant fruit. The use of molecular markers allows highly reliable detection of target gene alleles in a genome at early developmental stages. This study involves molecular genotyping of Fragaria L. varieties for the FaOMT and FaFAD1 genes, analysis of polymorphism of the loci in question, and identification of genotypes valuable for breeding. The objects of our study were wild species of the genus Fragaria L. and strawberry varieties (Fragaria × ananassa Duch.) of different ecological and geographic origins. To assess the allelic states of the FaOMT gene, the codominant marker FaOMT-SI/NO was used, and for the FaFAD1 gene, the dominant marker FaFAD1. The functional allele of the FaOMT gene (FaOMT+) in the heterozygous state (FaOMT+FaOMT– genotype) was detected in 34.9 % of the accessions tested. The functional allele of the FaOMT gene in the homozygous state (FaOMT+FaOMT+ genotype) was detected in 51.2 % of the accessions. The homozygous state of the inactive allele (FaOMT–FaOMT– genotype) was detected in 13.9 % of the studied strawberry accessions. The FaFAD1 gene was identified in 25.6 % of the analyzed collection of strawberry genotypes, including the wild species F. orientalis Los., F. moschata Duch., F. ovalis Rydb. The combination of functional alleles of the FaOMT and FaFAD1 genes was detected in 16.3 % of the analyzed forms. The wild species F. orientalis Los. and F. moschata Duch. and strawberry variety Red Gauntlet combine the functional allele of the FaFAD1 gene with the homozygous state of the active allele of the FaOMT gene; therefore, we recommend them as promising sources of high contents of mesifurane and γ-decactone in fruit in breeding programs for fruit aroma.

Red root spot (Phytophthora fragariae var. fragariae Hickman) is one of the most important strawberry diseases in the temperate climate zone. Identification of forms, carrying resistance genes, is an important stage in breeding programs aimed at obtaining red root spot resistant strawberry varieties. Diagnostic DNA markers of target genes will increase reliability of identification and efficiency of strawberry breeding for the creation of resistant genotypes. The purpose of this study is analysis of polymorphism of wild species of Fragaria L. genus and strawberry varieties (F. × ananassa Duch.) according to the strawberry red root spot resistance gene Rpf1 using molecular markers. The research sunjects were the wild species F. orientalis Los., F. moschata Duch., F. ovalis Rydb., F. virginiana Duch. ssp. platypetala and strawberry varieties (F. × ananassa Duch.) of different ecological and geographic origin. Total genomic DNA of strawberry was extracted from the fresh leaves using the Puchooa method. To assess the allelic state of Rpf1 gene, SCAR-R1A marker (linked to the Rpf1 dominant allele) and OPO-16C marker (linked to the rpf1 recessive allele) have been used. SCAR-R1A marker was identified in wild species F. virginiana Duch. ssp. platypetala (vegetation region: British Columbia, Canada), pineapple strawberry varieties Bylinnaya and promising selected forms 62-41 (Bylinnaya × Feyyerverk), 65-17 and 65-24 (Olimpiyskaya nadezhda × Bylinnaya). These genotypes are characterized by heterozygous Rpf1rpf1 genotype according to Rpf1 gene (both markers are present in genotype) and can be used as red root spot resistance source in marker-assisted selection. In the remaining studied genotypes of strawberry, SCAR-R1A marker was not detected, which presumably indicated their homozygous recessive genotype rpf1rpf1 according to Rpf1 gene. The research results can be useful for breeders of strawberry and researchers of plant biodiversity of p. Fragaria.

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Molecular genetic analysis revealed a polymorphism for the Md Exp7 gene that controls the bio synthesis of expansin in wild species of the genus Malus. Eight allelic forms of the gene were identified, four of which were unique. The regularities in the allele distribution in 37 genotypes were found to be in accor dance with their systematic positions. The trait was found to be broadly diverse both among the sections of the genus and within a particular section. Variants of the gene were identified in representatives of one species.

Background. Monogenic scab resistance is an important trait of apple, useful to plant breeders. DNA markers provide a possibility to differentiate apple cultivars according to individual resistance determinants with high reliability and identify promising genotypes. The present study shows the results of the molecular genetic analysis of apple varieties, targeted at the Rvi2, Rvi4, Rvi6 and Rvi8 monogenic scab resistance loci.Materials and methods. Biological material was represented by apple cultivars of different environmental and geographical origin. Total genomic DNA was extracted from fresh leaves using CTAB methods according to the DArT protocols. The Rvi6 gene was identified with two markers, VfC (STS) and AL07 (SCAR). The presence of the Rvi4 gene was detected with the multiallelic SCAR marker AD13. The Rvi2 and Rvi8 genes were diagnosed with the SCAR marker OPL19.Results and conclusion. The Rvi6 gene was identified in 54.4% of genotypes, of which 91.9% were heterozygous, and 8.1% (cvs. ‘Svezhest’, ‘Freedom’ and ‘GoldRush’) homozygous dominant for this locus. The marker AD13-SCAR was detected in 25.0% of the studied forms (the putative genotype for the resistance gene is Rvi4Rvi4 or Rvi4rvi4). The marker OPL19-SCAR (Rvi2 and Rvi8 genes) was present in 73.5% of the analyzed forms. At least one of the studied molecular markers was present in the genome of 86.8% of genotypes. The appletree cultivars ‘Kandil Orlovsky’, ‘Krasulya’, ‘Sozvezdiye’, ‘Galarina’, ‘Priam’, ‘Redfree’ and ‘Witos’ are characterized by the combination of markers VfC, AL07-SCAR, AD13-SCAR and OPL19-SCAR in one genotype (the putative genotype for the resistance genes is Rvi2(Rvi8)Rvi4Rvi6rvi6). Cvs. ‘Antonovka zimnyaya’, ‘Antonovka krasnaya’, ‘Berkutovskoye’, ‘Geyzer’, ‘Pamyati Nesterova’, ‘Renet Simirenko’, ‘Terentyevka’, ‘Golden Delicious’, and ‘Telemon’ presumably have a homozygous recessive genotype for the studied resistance loci.

Background. Anthracnose, caused by phytopathogenic fungi of the genus Colletotrichum, is one of the most important strawberry diseases. Strawberry yield losses from anthracnose lesions can reach 80%. Most strawberry cultivars are susceptible to anthracnose. Therefore, identification of the initial forms carrying resistance genes is a necessary step toward successful breeding of anthracnose-resistant cultivars. Use of molecular markers will increase reliability of identification and enhance effectiveness of strawberry breeding.Materials and methods. Biological material was represented by strawberry cultivars (Fragaria × ananassa Duch.) of various ecological and geographical origin. Total genomic DNA was extracted from the fresh leaves using the CTAB methods according to Puchooa (2004). To assess the allelic state of the Rca2 anthracnose resistance gene, the SCAR marker STS-Rca2_240 was used. The SCAR marker STS-Rca2_240 was multiplexed with the microsatellite marker EMFv020 used as the positive PCR control.Results and conclusion. The SCAR marker STS-Rca2_240, mapping at about 2.8 cM from the Rca2 gene, was identified in the strawberry cultivars ‘Elianny’, ‘Troubadour’ and ‘Sudarushka’. Cvs. ‘Elianny’ and ‘Troubadour’ are presumably characterized by a dominant homozygous (Rca2Rca2) or heterozygous (Rca2rca2) genotype. Cv. ‘Sudarushka’ has the heterozygous state for the Rca2 anthracnose resistance gene (Rca2rca2). In the remaining cultivars studied, the marker STS-Rca2_240 was not detected (the prospective genotype is rca2rca2).

For the last time a lot of attention has been paid to strawberry as a garden crop. All this thanks to its preventive and medical benefits related to the consumption of its fruit. The paper presents the data analysis of foreign and domestic researchers on the accumulation of basic food components (sugars, organic acids), vitamins, mineral substances and other valuable ones in. Which determine the high antioxidant properties of strawberries. On the basis of scientific literature sources, the vitamin profile was compiled wich reflects the accumulation of vitamin groups, specific for a given crop. With all diversity of vitamins found in strawberry fruits, the fruits of this plant are primarily good as a valuable source of ascorbic acid, folic acid, polyphenolic compounds (anthocyanins, ellagic acid). As for mineral substances, the presence of iron amount confirms the fact. In spite of fact that the strawberry composition is studied enough, the further detailed characterization of genetic resources is necessary both by total antioxidant activity and by definite chemical components, the last ones, obviously, present the antioxidant complex of strawberry fruits. The given information will be a base for future related investigations of phytochemical compounds of fruits and berries. They are extraordinary important in healthy food of humans as well as in creation of nutraceutical products.