Background. Top onion, Allium × proliferum (Moench) Schrad. ex Willd., 1809 (2n=2x=16), is a species that is characterized by vegetative propagation by air or underground bulbs only. Accessions of this species have been shown to be hybrids of Allium cepa and Allium fistulosum (Fiskesjo, 1975; Vosa, 1976; Schubert et al., 1983; Puizina and Papes, 1999). Accessions of Allium × proliferum were obtained from various sources and conserved in the in vitro collection of VIR. However, their pedigree was unknown, therefore there was a need to determine the ploidy level and genomic composition of these accessions.

Materials and Methods. Thirteen Allium × proliferum accessions from the VIR in vitro collection were studied. To characterize the ploidy level and genomic composition of the accessions, the research employed FISH with chromosome-specific markers (5S and 18S/25S rDNA) and GISH with differentially labeled DNA of the putative parent species, i.e., A. cepa and A. fistulosum.

Results. According to GISH, all the studied accessions were hybrids of A. cepa and A. fistulosum. Most (10 out of 13) accessions were determined as diploid hybrids with eight A. cepa and eight A. fistulosum chromosomes. The accession К 3206 turned out to be a diploid 16-chromosome hybrid with eight A. cepa, seven A. fistulosum chromosomes and one rearranged chromosome. Accessions К 3205 and К 3202 were found to be polyploids. The A. × proliferum accession К 3202 contained seven A. cepa and 16 A. fistulosum chromosomes. The accession К 3205 is characterized by the presence of 16 chromosomes hybridizing with A. cepa DNA and 13 chromosomes hybridizing with A. fistulosum DNA. Only one chromosome of A. fistulosum in this accession was revealed to have a 5s rDNA locus.

Conclusions. The above shows that the collection contains top onion accessions with karyotypic differences. 

Table grapes are a valuable dietary product. Seedless grapes are in high demand among consumers. For this reason, the breeding of seedless varieties is one of the popular trends in modern viticulture, along with the production of environmentally friendly products. Downy mildew (Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Toni) is one of the most common fungal diseases of the grapevine. Most downy mildew resistant grape accessions belong to North American species like Vitis aestivalis Michx., V. berlandieri Planch., V. cinerea (Engelm. ex A. Gray) Engelm. ex Millard, V. riparia Michx., V. rupestris  Scheele, etc. The search for donors of resistance genes is an urgent task. Rpv3 is one of the most significant resistance genes from a number of North American grape varieties. The aim of this work is to identify the downy mildew resistance gene Rpv3 in seedless grape varieties by means of DNA-marker analysis. The grape varieties with rudimentary development of seed in berries and with North American species in the pedigree were chosen as the object of the study. The varieties “Dunavski lazur” and “Seyve Villard 12-375” with reference alleles were used as the positive control, while V. vinifera L. was used as the negative control. UDV305 and UDV737 DNA-markers were used in this study to identify the allelic type of the Rpv3 gene. The work was performed using the polymerase chain reaction. The reaction products were separated by capillary electrophoresis using the ABI Prism 3130 automatic genetic analyzer. Evaluation of the results was done using the GeneMapper and PeakScanner software. Functional alleles of the downy mildew resistance gene Rpv3 were revealed in grape  varieties “Kishmish zaporozhskiy”, “Lady Patricia”, “Remaily seedless”, “Pamyati Smirnova” and “Shayan”. Rpv3^299-279, one of the seven known haplotypes, was identified in all the varieties. The pedigree analysis of the studied varieties indicated that the parental forms – “Seyve Villard” and “Seibel” hybrids – are presumably the donors of the gene. Grape accessions with the identified Rpv3 gene can be used in seedless varieties breeding as donors of resistance to downy mildew.

This study is focused on evaluation of the genetic structure and diversity of the national sorghum collection. Analyzing the genetic diversity of crop species is of great importance for genetic resources management and food security of any country. Huge genetic diversity of sorghum provides a great opportunity to improve the agronomic characteristics of this crop. The efficiency of microsatellite  analysis has been demonstrated in many studies on the genetic diversity of different races and geographical groups of sorghum plants. Development of multiplex PCR analysis systems based on a set of polymorphic microsatellite loci will facilitate genetic tests on a large number of plant samples, thus making the research on sorghum diversity more efficient and comprehensive. A system of multiplex PCR analysis based on 12 polymorphic microsatellite loci was developed to perform single-stage high-throughput screening of cultivated and wild forms preserved in the sorghum germplasm collection. As a result of the microsatellite analysis of 200 sorghum plants, 229 alleles were detected. The studied loci showed high polymorphism. More than 17 alleles were identified in most loci, their polymorphic index content (PIC) ranging from 0.694 to 0.954. The value of the effective multiplex ratio (EMR) in the developed system was estimated at 0.833. The microsatellite analysis of sorghum accessions resulted in obtaining quantized gene expressions profiles, with a DNA profile for each accession, and revealed significant polymorphism among the plants of different sorghum varieties (races). The developed multiplex PCR system was shown to be efficient for evaluation of the genetic diversity and genetic relationships of sorghum plants from different races. The analysis of the obtained data using three bioinformatic techniques, NJ cluster analysis, PCoA, and the Bayesian model-based clustering, helped to classify the analyzed sorghum accessions into cluster groups according to their morphological and agronomic traits.

The garden strawberry Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier (1785) is a perennial herbaceous plant of the Rosaceae family; it is cultivated all around the world. It accounts for more than half of the global volume of berries production. In Russia, more than 160 tons of garden strawberries are grown annually, but according to Russian scientists, this crop has a much higher productivity potential. Various pathogens, including bacterial, viral and fungal infections, negatively affect the productivity of strawberry. Anthracnose (caused by Colletotrichum Corda.), crown rot (Phytophthora cactorum Lebert & Cohn), red core disease (Phytophthora fragariae var. fragariae Hickman), fusarium wilt (Fusarium oxysporum f. sр. fragariae Winks & Williams ) and strawberry powdery mildew (Podosphaera aphanis [Sphaerotheca macularis] (Wallr.) U. Braun & S. Takam) are among the most important fungal diseases of strawberry. This review discusses the current data about the known genes and quantitative trait loci (QTLs) associated with resistance to listed plant pathogens. The review also offers information about molecular markers of different types: SDRF, AFLP, SSR, SCAR, SNP, associated with these genes/QTLs and used in the molecular screening of strawberry collections for practical purposes.

The paper presents a review of the studies on the use of genetic engineering and genome editing tools for improving nutritional properties of sorghum grain. As a result of experiments performed over the past 5-7 years by several research groups, the created transgenic lines carry genetic constructs for RNA silencing of different kafirin sub-classes (prolamins of sorghum grain). The CRISPR/Cas9 genome editing experiments have yielded mutants with deletions and insertions in the signal sequence of the gene encoding the 22 kDa α-kafirin in sorghum. These lines and mutants were characterized by improved in vitro digestibility of grain proteins, altered ultrastructure of protein bodies and an increased content of lysine. RNA silencing of α-kafirin increased the digestibility of proteins of both raw and cooked flour, while silencing of γ-kafirin led to improved digestibility of proteins of only raw flour. The lines with α-kafirin silencing have kernels with the floury endosperm type that discourages their direct commercial use because of fragility and reduced tolerance to fungal contamination; however, these lines can be used as donors of high digestibility trait when crossed with sorghum lines adapted to local conditions to improve their nutritional value. Kernels of the lines with γ-kafirin silencing may have different endosperm types: floury, vitreous, or a modified type with vitreous endosperm interspersed in the floury endosperm. This fact indicates the possibility of producing agronomically important sorghum lines with high kafirin digestibility and hard endosperm. The increased lysine level in kernels of sorghum lines with the suppressed synthesis of kafirins may be caused by rebalancing of protein synthesis in endosperm of developing kernels due to the synthesis of other proteins, including those with a higher content of essential amino acids. Alongside with improving the digestibility of kafirins, the genetic engineering approach allowed the creation of sorghum lines with a high content of provitamin A in grain and its increased stability during long-term storage. The results of these works show that it is promising to use RNA-interference and genome editing for creating sorghum lines with improved nutritional value of grain.