Dioecy is relatively rare in plants and sex determination systems vary among such species. A good example of a plant with heteromorphic sex chromosomes is hop (Humulus lupulus). The genotypes carrying XX or XY chromosomes correspond to female and male plants, respectively. Until now no clear cytogenetic markers for the sex chromosomes of hop have been established. Here, for the first time the sex chromosomes of hop are clearly identified and characterized. The high copy sequence of hop (HSR1) has been cloned and localized on chromosomes by fluorescence in situ hybridization. The HSR1 repeat has shown subtelomeric location on autosomes with the same intensity of the signal. The signal has been present in the subtelomeric region of the long arm and in the near-centromeric region but absent in the telomeric region of the short arm of the X chromosome. At the same time the signal has been found in the telomeric region only of the long arm of the Y chromosome. This finding indicates that the sex chromosomes of hop have evolved from a pair of autosomes via ancient translocation or inversion. The observation of the meiotic configuration of the sex bivalents shows the location of a pseudoautosomal region on the long arms of X and Y chromosomes.

The optimization of all constituent conditions to obtain high and even maximum yields is a recent trend in agriculture. Legumes play a special role in this process, as they have unique characteristics with respect to storing protein and many other important components in their seeds that are useful for human and animal nutrition as well as industry and agriculture. A great advantage of legumes is the nitrogen fixation activity of their symbiotic nodule bacteria. This nitrogen self-sufficiency contributes directly to the challenging issue of feeding the world’s growing population. Molybdenum is one of the most sought-after nutrients because it provides optimal conditions for the maximum efficiency of the enzymes involved in nitrogen assimilation as well as other molybdenum-containing enzymes in the host plant and symbiotic nodule bacteria. In this review, we consider the most optimal way of providing legume plants with molybdenum, its distribution in ontogeny throughout the plant, and its accumulation at the end of the growing season in the seeds. Overall, molybdenum supply improves seed quality and allows for the efficient use of the micronutrient by molybdenum-containing enzymes in the plant and subsequently the nodules at the initial stages of growth after germination. A sufficient supply of molybdenum avoids competition for this trace element between nitrogenase and nodule nitrate reductase, which enhances the supply of nitrogen to the plant. Finally, we also consider the possibility of regulating molybdenum homeostasis using modern genetic approaches.

Aegilops crassa Boiss. is polyploid grass species that grows in the eastern part of the Fertile Crescent, Afghanistan, and Middle Asia. It consists of tetraploid (4x) and hexaploid (6x) cytotypes (2n = 4x = 28, D¹D¹X^crX^cr and 2n = 6x = 42, D¹D¹X^crX^crD²D², respectively) that are similar morphologically. Although many Aegilops species were used in wheat breeding, the genetic potential of Ae. crassa has not yet been exploited due to its uncertain origin and significant genome modifications. Tetraploid Ae. crassa is thought to be the oldest polyploid Aegilops species, the subgenomes of which still retain some features of its ancient diploid progenitors. The D¹ and D² subgenomes of Ae. crassa were contributed by Aegilopstauschii (2n = 2x = 14, DD), while the X^cr subgenome donor is still unknown. Owing to its ancient origin, Ae. crassa can serve as model for studying genome evolution. Despite this, Ae. crassa is poorly studied genetically and no genome sequences were available for this species. We performed low-coverage genome sequencing of 4x and 6x cytotypes of Ae. crassa, and four Ae. tauschii accessions belonging to different subspecies; diploid wheatgrass Thinopyrum bessarabicum (J^b genome), which is phylogenetically close to D (sub)genome species, was taken as an outgroup. Subsequent data analysis using the pipeline RepeatExplorer2 allowed us to characterize the repeatomes of these species and identify several satellite sequences. Some of these sequences are novel, while others are found to be homologous to already known satellite sequences of Triticeae species. The copy number of satellite repeats in genomes of different species and their subgenome (D¹ or X^cr) affinity in Ae. crassa were assessed by means of comparative bioinformatic analysis combined with quantitative PCR (qPCR). Fluorescence in situ hybridization (FISH) was performed to map newly identified satellite repeats on chromosomes of common wheat, Triticum aestivum, 4x and 6x Ae. crassa, Ae. tauschii, and Th. bessarabicum. The new FISH markers can be used in phylogenetic analyses of the Triticeae for chromosome identification and the assessment of their subgenome affinities and for evaluation of genome/chromosome constitution of wide hybrids or polyploid species.

Winter durum wheat is a relatively young crop that is highly adaptable due to its winter type of growth habit. The priority of breeding and genetic improvement of winter durum wheat is to improve grain quality and pasta quality, largely determined by the glutenin storage proteins. In the present study, a collection of 76 accessions of winter durum wheat from P.P. Lukyanenko National Grain Centre was studied. The allelic state of high-molecular-weight glutenin genes, Glu-A1 and Glu-B1, using PCR markers and SDS-PAGE was identified and grain and pasta quality traits were assessed in a two-year field experiment. The positive effect of the Glu-A1a allele and a negative effect of Glu-A1c on the gluten index were shown. It was found that Glu-B1al and Glu-B1f have a positive effect on the quality and quantity of protein and gluten, while the Glu-A1c + Glu-B1al genotypes were closest to the high-quality category in protein-associated quality traits.

Sugar beet is an important root crop with a biennial life cycle. In the first year of its life cycle, it produces huge amounts of leaf and root mass used for the production of sugar and bioethanol, livestock feed, confectionery and pharmaceuticals, fertilizers, and soil restoration. Normally, after exposure to cold temperatures during winter storage, in the second year of its life cycle, it enters its reproductive phase. However, during the first year of growth, sugar beet plants may be susceptible to producing flowering shoots, or “bolting”, due to vernalization and long-day conditions. Bolting reduces both the yield and the sugar content of roots. Here, we review the published research works that study the environmental factors influencing bolting, the genetic (including epigenetic) and physiological mechanisms that regulate the transition to the reproductive phase, and the agrotechnical and breeding practices used to prevent bolting. Models of gene networks that regulate the transition to flowering are presented. Methods for selecting non-bolting plants using conventional, marker-assisted, and genomic breeding are demonstrated. Attention is also paid to the speed breeding technology that stimulates bolting and flowering sugar beet plants in an artificial climate. Growing sugar beet plants “from seed to seed” can potentially accelerate the breeding and seed production of sugar beet. This review compares different conditions for inducing bolting in sugar beet in climatic chambers and greenhouses. It examines parameters such as temperature, duration of light exposure, and light intensity during the pre-vernalization, post-vernalization, and vernalization periods. The present review may be useful for specialists in sugar beet cultivation, breeders working on developing cultivars and hybrids that are resistant to bolting, and molecular biologists studying the genetic and physiological mechanisms underlying the transition of plants into the flowering stage.

Spring durum wheat is an important raw material for producing diverse products such as couscous, bulgur, bread, and pasta. The quality of the dough is significantly influenced by high-molecular-weight glutenins, the allelic status of which depends on the region and breeding program. In this study, a collection of 69 cultivars and promising lines of durum wheat were analyzed for the allelic state of Glu-A1 and Glu-B1 using SDS-PAGE and KASP PCR markers. Protein and gluten content, volume increase index, pasta breaking strength, general pasta estimation, SDS, and gluten index were measured for each accession based on a two-year field experiment in the Krasnodar region. The analysis revealed that the Glu-B1al, Glu-B1d, and Glu-B1z* alleles positively influence gluten index, with Glu-B1al increasing protein, gluten, and SDS content, whereas Glu-B1d decreased these traits. Glu-B1e, on average, decreased the gluten index and SDS value but did not affect protein or gluten content. The role of alleles affecting the gluten index and protein content in ensuring the quality of pasta in durum wheat breeding is discussed.