Description of the genetic collection of strawberry (<i>Fragaria × ananassa</i> Duch.) cultivars according to the components of their fruit antioxidant complex

Background. Quality indicators, medicinal and prophylactic properties of strawberry fruits are largely determined by their chemical composition. In order to improve the breeding work, it is necessary to look for the sources of high-level accumulation of macro- and micronutrients in fruits.Materials and methods. Fruits of 101 accessions from the genetic collection of introduced foreign and domestic cultivars, elite and selected forms held by the I.V. Michurin Federal Science Center were used as the target research material. All of them were grown on the experimental plantations from 1994 through 2020. Their chemical composition (ascorbic acid and anthocyanin contents) was analyzed at the Laboratory of Biochemistry and Food Technologies according to the standard methods.Results and conclusions. The ranges of variability in the accumulation of primary components of the antioxidant complex in strawberry fruits in the environments of the Central Black Earth Region (Michurinsk) were measured: 30.1–102.3 mg/100 g for ascorbic acid and 3.6–124.5 mg/100 g for anthocyanins. The cultivars were ranked according to the analyzed chemical components. A majority of them were classified into the group with average vitamin C content (50.1–90.0 mg/100 g). The largest part (85.6%) of the studied cultivars accumulated anthocyanins within the range of 30.0–70.0 mg/100 g. Valuable genotypes with high levels of ascorbic acid (above 90.1 mg/100 g) were identified: cvs. ‘Kokinskaya zarya’, ‘Lirovidnaya’, ‘Sudarushka’ and ‘Zephyr’. As for anthocyanins (above 90.1 mg/100 g), cvs. ‘Alena’, ‘Istochnik’, ‘Pamyati Zubova’, ‘Privlecatelnaya’, ‘Rubinovy kulon’, ‘Torpeda’ and ‘Feyerverk’, plus the elite seedling 56-5 (“Rubinovy kaskad”), showed the best results. The identified genotypes are of interest both for consumers, as they yield highly vitaminized fresh fruits, and for breeders as source material for the development of cultivars with improved chemical composition

Polymorphism of the <i>Rca2</i> anthracnose resistance gene in strawberry cultivars (<i>Fragaria × ananassa</i>)

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)

Polymorphism of the <i> FaOMT </i> and <i> FaFADl </i> genes for fruit flavor volatiles in strawberry varieties and wild species from the genetic collection of the Michurin Federal Research Center

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 y-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 y-decalactone content in strawberry fruit is controlled by the FaFADl 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 FaFADl 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 (Fragariax 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 FaFADl 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 FaFADl 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 FaFADl 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 FaFADl 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 y-decactone in fruit in breeding programs for fruit aroma

TECHNOLOGICAL FEATURES OF FIRING CERAMIC PRODUCTS EMACIATED WITH TPP ASH

The paper considers the assessment of the ongoing physical and chemical processes during the firing of ceramic products using technogenic raw materials at the heating stage. The graphical dependences of the thermal analysis of the alumina material are presented.В работе рассмотрена оценка протекающих физико-химических процессов при обжиге керамических изделий с использованием техногенного сырья на стадии нагрева. Приведены графические зависимости термического анализа глинозольного материала

Alternative technology to manufacture bimetallic products by using self-propagating high temperature synthesis

Electric welding is usually used for surfacing metal products. This process may be laborious and timeconsuming, which at the same time excludes welding jointing throughout the product surface. The productivity of powder tape surfacing is pretty low, up to 2.7 kg / h, with a melting rate of 13-15 min / h. The use of the selfpropagating high-temperature synthesis for producing a liquid thermite alloy aimed at further surfacing throughout the metal surface of a detail can provide a cost-effective and viable alternative technology for manufacturing bimetallic products