Beet Accessions Research Articles

Chromosome 1 QTLs associated with response to bacterial leaf spot in Beta vulgaris

AbstractBacterial leaf spot (BLS), caused by Pseudomonas syringae pathovar aptata (Psa), is a seedborne, foliar disease affecting members of the Amaranthaceae and Cucurbitaceae families, including table beet and Swiss chard crops. There is no known resistance to BLS in beet or chard. A diversity panel, modified from the Wisconsin Beta Diversity Panel (WBDP) and comprised of 219 accessions from the Beta vulgaris crop complex, was assembled and genotyped for single nucleotide polymorphism data. These accessions were screened by foliar inoculation of Psa and visually evaluated for percentage of diseased leaf tissue. Overall, sugar beet and Beta vulgaris subsp. maritima accessions had the lowest BLS response, whereas table beet accessions had the largest range of responses. Phenotypic means were adjusted using best linear unbiased estimates, and two different software programs, GWASpoly and GAPIT3, were utilized to conduct a genome‐wide association study (GWAS). Leaf color was found to be significantly associated with and correlated with BLS response scores, and was used as a covariate in GWAS analysis. An association with BLS response was detected on chromosome 1 in the full WBDP, explaining upward of 21% of the variation in the phenotype. The marker associated with this quantitative trait locus (QTL), Chr1_61344476, showed an additive relationship between dosage and BLS response. Eleven candidate genes, described and annotated in sugar beet, were associated with this QTL. Some of these include F Box domains, RNA‐binding proteins, and calcium‐dependent kinases, all of which have roles in plant defense responses. Marker Chr1_61344476 may be useful in breeding for BLS resistance in members of the Beta vulgaris crop complex.

Rapid and Visual Screening of Virus Infection in Sugar Beets Through Polerovirus-Induced Gene Silencing.

Since the ban of neonicotinoid insecticides in the European Union, sugar beet production is threatened by outbreaks of virus yellows (VY) disease, caused by several aphid-transmitted viruses, including the polerovirus beet mild yellowing virus (BMYV). As the symptoms induced may vary depending on multiple infections and other stresses, there is an urgent need for fast screening tests to evaluate resistance/tolerance traits in sugar beet accessions. To address this issue, we exploited the virus-induced gene silencing (VIGS) system, by introducing a fragment of a Beta vulgaris gene involved in chlorophyll synthesis in the BMYV genome. This recombinant virus was able to generate early clear vein chlorosis symptoms in infected sugar beets, allowing easy and rapid visual discernment of infected plants across five sugar beet lines. The recombinant virus displayed similar infectivity as the wild-type, and the insert remained stable within the viral progeny. We demonstrated that the percentage of VIGS-symptomatic plants was representative of the infection rate of each evaluated line, and depending on the susceptibility of the line to BMYV infection, VIGS symptoms may last over months. Our work provides a polerovirus-based VIGS system adapted to sugar beet crop allowing visual and rapid large-scale screens for resistance or functional genomic studies.

Genetic architecture of Cercospora leaf spot response in table beet with implications for other Beta vulgaris crop types

AbstractTable beet (Beta vulgaris subsp. vulgaris) production is threatened by the fungal disease Cercospora leaf spot (CLS). Infections are common across table beet's closest relatives, including Swiss chard, sugar beet, and fodder beet (all B. v. subsp. vulgaris). This study was conducted to characterize the genetic architecture underlying CLS response in table beet. A secondary objective was to test whether CLS‐associated loci in table beet perform similarly across B. vulgaris crops. A diversity panel comprised of 168 table beet accessions and with an additional 70 accessions from all close relatives of table beet was screened for CLS response in replicated and inoculated field trials. Results from a genome‐wide association study of additive effects revealed seven quantitative trait loci mapped to chromosomes 1, 3, 7, and 9 to explain 30% of the phenotypic variation for CLS response in table beet. When the performance of these loci was compared between a table beet background and a background of Swiss chard, sugar beet, and fodder beet, two loci exhibited significantly different responses. Among the B. vulgaris crops, these loci may be unique to table beet germplasm and could be useful for the improvement of CLS resistance in other crop types. For the improvement of CLS resistance in table beet, this study identified the cultivar Winter Keeper as a potentially valuable source of resistance. The architecture of CLS response points to recurrent selection and backcross methods as effective strategies for the improvement of CLS resistance in table beet.

Genome-wide association study identifies the genetic basis of key agronomic traits in 207 sugar beet accessions.

Sugar beet (Beta vulgaris) has emerged as one of the two primary crops, alongside sugarcane, for global sugar production. Comprehensively understanding sucrose synthesis, transport, and accumulation in sugar beet holds great significance for enhancing sugar production. In this study, we collected a diverse set of 269 sugar beet accessions worldwide and measured 12 phenotypes, comprising biomass, soluble sugar content, and 10 taproot-related traits. We re-sequenced 207 accessions to explore genetic diversity and population structure. Then we employed a genome-wide association study (GWAS) and RNA-seq to identify single-nucleotide polymorphisms and genes associated with natural phenotypic variations. Our findings revealed a panel of genes potentially regulating biomass and sugar accumulation, notably the dual-role gene UDP-glucose 4-epimerase, which genetically balances sugar accumulation and cell wall synthesis. In summary, this study provides a foundation for molecular breeding in sugar beet.

Characterization of Betalain Content and Antioxidant Activity Variation Dynamics in Table Beets (Beta vulgaris L.) with Differently Colored Roots

Antioxidant properties, betalain profiles and biochemical composition were studied in table beets with maroon and yellow root colors. Features of dynamic changes during the growing season were described. Significant differences in antioxidant activity were found in table beet accessions with differently colored roots. Negative dynamics of antioxidant activity were observed in all accessions. Statistically significant differences were registered among the accessions in the total amounts of phenolic compounds, chlorophylls, and betalains. The group of maroon accessions demonstrated strong positive correlations between their antioxidant activity and total phenolics (r = 0.91), antioxidant activity and betacyanins (r = 0.80), and between betacyanins and phenolics (r = 0.90). The antioxidant activity in the accessions with yellow roots was associated with chlorophyll b (r = 0.85), ascorbic acid (r = 0.83), and total phenolics (r = 0.83). The data are presented on the structure of betalains in two table beet groups contrasting in their root color. The results of the study made it possible to identify key components in the biochemical profile of differently colored beetroots, associated with their high antioxidant activity. Dynamic changes were shown for the antioxidant activity and fractional composition of betalains in table beet during its growing season, and a conclusion was made concerning the higher nutritional value of maroon cultivars.

Allelic differences in the key genes of betalain biosynthesis in table beet accessions with contrasting root color from the VIR collection

Background. Table beet (Beta vulgaris L.) contains a great amount of naturally red-colored betanins. A number of enterprises are forced to import foreign dyes because the reserves of domestic plant raw materials are insufficient. With this in view, the development of cultivars with high betalain pigment content is now required.Materials and methods. Allelic differences were screened in the key genes of the betalain biosynthesis pathway among table beet accessions with various root color from the VIR collection using the Sanger DNA sequencing method.Results and discussion. For the first time we identified a nonsense mutation in the CYP76AD1 gene in cv. ‘Serdolik’ with yellow flesh; it led to the truncation of the functional P450 domain. We suggested that the detected polymorphism correlated with phenotypic switching because the well-known role of CYP76AD1 was essential for the red betalain accumulation. Moreover, a number of missense mutations in cv. ‘Avalanche’ in the first exon of the BvDODA1 gene were found. These mutations were probably associated with the expression of the uncolored phenotype. An in silico analysis revealed highly homologous copies of CYP76AD5, located tandemly on chromosome 9. Attention should be paid to these copies, together with the CYP76AD6 gene, as they seem the most preferable targets for a knockout to increase the red pigment content.Conclusion. It is possible to identify the best table beet accessions for further genome editing among a previously selected high-betanin group. In addition, this study revealed the allelic differences in the key genes of the betalain biosynthesis pathway. These results will be useful for the development of DNA molecular markers to facilitate the selection of table beet forms with required properties.

Applicability of SCoT markers in unraveling genetic variation and population structure among sugar beet (Beta vulgaris L.) germplasm.

Sugar beet (Beta vulgaris L.) holds significant importance as a crop globally cultivated for sugar production. The genetic diversity present in sugar beet accessions plays a crucial role in crop improvement programs. During the present study, we collected 96 sugar beet accessions from different regions and extracted DNA from their leaves. Genomic DNA was amplified using SCoT primers, and the resulting fragments were separated by gel electrophoresis. The data were analyzed using various genetic diversity indices, and constructed a population STRUCTURE, applied the unweighted pair-group method with arithmetic mean (UPGMA), and conducted Principle Coordinate Analysis (PCoA). The results revealed a high level of genetic diversity among the sugar beet accessions, with 265 bands produced by the 10 SCoT primers used. The percentage of polymorphic bands was 97.60%, indicating substantial genetic variation. The study uncovered significant genetic variation, leading to higher values for overall gene diversity (0.21), genetic distance (0.517), number of effective alleles (1.36), Shannon's information index (0.33), and polymorphism information contents (0.239). The analysis of molecular variance suggested a considerable amount of genetic variation, with 89% existing within the population. Using STRUCTURE and UPGMA analysis, the sugar beet germplasm was divided into two major populations. Structure analysis partitioned the germplasm based on the origin and domestication history of sugar beet, resulting in neighboring countries clustering together. The utilization of SCoT markers unveiled a noteworthy degree of genetic variation within the sugar beet germplasm in this study. These findings can be used in future breeding programs with the objective of enhancing both sugar beet yield and quality.

Genetic diversity and genome-wide association study of 13 agronomic traits in 977 Beta vulgaris L. germplasms

BackgroundSugar beet (Beta vulgaris L.) is an economically essential sugar crop worldwide. Its agronomic traits are highly diverse and phenotypically plastic, influencing taproot yield and quality. The National Beet Medium-term Gene Bank in China maintains more than 1700 beet germplasms with diverse countries of origin. However, it lacks detailed genetic background associated with morphological variability and diversity.ResultsHere, a comprehensive genome-wide association study (GWAS) of 13 agronomic traits was conducted in a panel of 977 sugar beet accessions. Almost all phenotypic traits exhibited wide genetic diversity and high coefficient of variation (CV). A total of 170,750 high-quality single-nucleotide polymorphisms (SNPs) were obtained using the genotyping-by-sequencing (GBS). Neighbour-joining phylogenetic analysis, principal component analysis, population structure and kinship showed no obvious relationships among these genotypes based on subgroups or regional sources. GWAS was carried out using a mixed linear model, and 159 significant associations were detected for these traits. Within the 25 kb linkage disequilibrium decay of the associated markers, NRT1/PTR FAMILY 6.3 (BVRB_5g097760); nudix hydrolase 15 (BVRB_8g182070) and TRANSPORT INHIBITOR RESPONSE 1 (BVRB_8g181550); transcription factor MYB77 (BVRB_2g023500); and ethylene-responsive transcription factor ERF014 (BVRB_1g000090) were predicted to be strongly associated with the taproot traits of root groove depth (RGD); root shape (RS); crown size (CS); and flesh colour (FC), respectively. For the aboveground traits, UDP-glycosyltransferase 79B6 (BVRB_9g223780) and NAC domain-containing protein 7 (BVRB_5g097990); F-box protein At1g10780 (BVRB_6g140760); phosphate transporter PHO1 (BVRB_3g048660); F-box protein CPR1 (BVRB_8g181140); and transcription factor MYB77 (BVRB_2g023500) and alcohol acyltransferase 9 (BVRB_2g023460) might be associated with the hypocotyl colour (HC); plant type (PT); petiole length (PL); cotyledon size (C); and fascicled leaf type (FLT) of sugar beet, respectively. AP-2 complex subunit mu (BVRB_5g106130), trihelix transcription factor ASIL2 (BVRB_2g041790) and late embryogenesis abundant protein 18 (BVRB_5g106150) might be involved in pollen quantity (PQ) variation. The candidate genes extensively participated in hormone response, nitrogen and phosphorus transportation, secondary metabolism, fertilization and embryo maturation.ConclusionsThe genetic basis of agronomical traits is complicated in heterozygous diploid sugar beet. The putative valuable genes found in this study will help further elucidate the molecular mechanism of each phenotypic trait for beet breeding.

Primary metabolites and betanin: their interplay in the roots of Table Beet (Beta vulgaris L.)

Relevance. The main source of the natural pigment betanin is table beet, known for its medicinal and antioxidant properties, earliness and long shelf life, rich in bioactive compounds, minerals and vitamins. This research was induced by the lack of information required by breeders to increase betanin content in beet. Metabolite profiling is an effective way to assess the interplay between individual metabolites and betanin content in table beet.Materials and methods. The material was selected from the the N.I. Vavilov Institute of plant industry (VIR) collection. Biochemical analysis was based on VIR’s guidelines, and metabolite profiling on gas chromatography, coupled with mass spectrometry.Results. 17 free amino acids were found in the beet root extract. The greatest number of positive correlations with other amino acids (r˃0.72) was found in tyrosine, alanine and phenylalanine. A significant (r = –0.66) negative correlation was observed between betanin and succinic acid, credibly associated with betalamic acid. Sucrose predominated among carbohydrates (95%). Sucrose and maltose showed a weak positive correlation with betanin. Unsaturated oleic and saturated palmitic acids dominated among fatty acids (52% and 20% of total fatty acids, respectively). Earlier-ripening and cold-resistant table beet accessions showed a predominance of unsaturated fatty acids and lower betanin content. The disclosed interactions are important for betanin-rich red beet breeding.

Genetic diversity of the table beet (<I>Beta</I> L.) collection at VIR as a potential source for breeding (a review)

This review presents brief information about the history of the table beet (Beta vulgaris L. subsp. vulgaris var. conditiva Alef.) collection at the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR), its composition, research trends, and significance for domestic breeding. The collection started in 1924 with Vavilov’s collecting activities. Currently, the collection consists of 2512 accessions; the table beet variety is represented by 461 accessions from 45 countries, collected in numerous expeditions, obtained from foreign genebanks through germplasm exchange and seed requests, received from domestic and foreign breeders, plus materials developed by VIR researchers. Table beet is an economically important, high-yielding, ubiquitous crop that has a wide cultivation area and is a valuable biochemical food product with beneficial effects on human health.The information is provided on the genetic diversity of VIR’s table beet collection, including current trends of its study and use in breeding. Characteristics of table beet accessions available in the collection, their morphological features and value, and the names of accessions from different trait groups and genetic sources are described. Presently, 125 cultivars and 38 F1 hybrids of table beet are listed in the State Register of Breeding Achievements of the Russian Federation, 70% of which are products of domestic breeding.

Betalain Content and Morphological Characteristics of Table Beet Accessions: Their Interplay with Abiotic Factors

Table beet (Beta vulgaris L.) is a source of the natural red-colored food dye (E162), highly demanded for the broad spectrum of its biological activity. The relevance of this study is dictated by the lack of knowledge about the dynamics of changes in the crop’s betalain content during the growing season, which impedes identifying the optimal timing of harvesting in order to obtain the dye. This paper presents the results of research into betacyanins (BC) and betaxanthins (BX), separately in the peel and flesh of roots, in 15 differently colored table beet accessions from the collection of the N.I. Vavilov Institute (VIR). There was no statistically significant accumulation of betalains in beets during the growing season. The pigment’s significant fluctuations associated with abiotic environmental factors were shown. The ratio of BC/BX in red-colored accessions was measured: 2.65 in the peel and 2.9 in the flesh. Strong positive relationships were found between BC and BX in the peel (r = 0.97) and flesh (r = 0.79) of red-colored biotypes, which stably persisted throughout the growing season. The beetroot peel was more sensitive to temperature changes, in contrast to the flesh. The negative effect of a temperature increase on betalains in red-colored beetroots intensified on the second or third day. The pigment composition of the flesh was less susceptible to the negative impact of increased temperatures, but reacted negatively to rainfall, becoming more expressed on the second or third day. A conclusion was made about the morphotype with high betalain content. Recommended cultivars are mid-ripening, with rounded and medium-sized roots, a large number of narrow leaf blades, and short and thin petioles.

Dynamic changes in betanin content during the growing season of table beet: their interplay with abiotic factors.

The table beet, a widespread edible root crop known for its medicinal and antioxidant properties, early maturation, good shelf life, and high contents of bioactive compounds, vitamins and minerals, is used for the production of a natural red food dye. The relevance of this study is dictated by the lack of knowledge about the dynamic changes in the content of betanin during the growing season when developing table beet cultivars with a focus on pigment extraction. The article presents the results of a study of 29 red-colored table beet accessions from the collection of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR). Dynamic changes in the content of the pigment during the growing season were observed on two beet accessions, cvs. ‘Russkaya odnosemyannaya’ and ‘Bordo odnosemyannaya’. Four pH versions of the buffer solution were tested, and the test results are presented. A buffer solution with pH 6.5 is recommended for research purposes. The amplitude of variability in the content of betanin in the peel (39.9–239.2 mg/100 g) and f lesh (14.4–127.5 mg/100 g) of beets was determined. It was conf irmed that the content of betanin in the peel exceeded that in the f lesh in all samples. A positive relationship between these indicators was revealed (r = 0.74, p ≤ 0.05). It was found that betanin accumulation did not occur in beet roots during the growing season. The pigment showed considerable f luctuations associated with abiotic environmental factors. Correlation analysis showed a signif icant positive relationship between air temperature and betanin content in the root f lesh (r = 0.32–0.31, p ≤ 0.05). A negative impact of environmental temperature on betanin content in the peel manifested itself on the third day (r = –0.34…–0.35, p ≤ 0.05). The negative response to precipitation was less expressed in cv. ‘Bordo odnosemyannaya’ due to the genotype’s more active metabolism and plasticity. Structural morphological features of the photosynthetic apparatus were described for the tested accessions, and their interrelations with the studied character were specif ied. Recommendations are given concerning the choice of a planting pattern and the timing of table beet harvesting for pigment extraction

Elucidation of genetic diversity among some accessions of sugar beet (Beta vulgaris L.) using inter-simple sequence repeats (ISSR) markers

BackgroundSugar beet is considered a very important strategic economic crop, as it comes at the second place for white sugar production in Egypt after sugar cane and the sugar percentage in its roots is 20%. This work was conducted in Egypt as a direct response to bridge the gap which began to expand significantly between the production and consumption of white sugar and the desire for the genetic improvement process to increase the productivity of this crop. Further, as serious attempt to understand the nature of the genetic diversity among a group of sugar beet accessions with different origins, it constitutes an important source for establishing a program of breeding and improving sugar beet crop under Egyptian conditions.ResultsThe process of verifying the existence of significant genetic variation between the eight sugar beet varieties with various origins was carried out through a set of genetic parameters through two growing seasons besides, the data of ISSR markers profile. Further, all the sugar beet varieties were superior in all the studied traits during their evaluation over two agricultural years, where the two sugar beet accessions Oscar Poly and Rass Poly are superior in TSS % and sucrose % traits, Mont Bianco and Sultan in apparent purity % trait, Blino and Sultan in root yield and top yield traits and Rass Poly and Blino in sugar yield trait, respectively. In addition, the values of heritability in broad sense were high in all studied traits except the two traits; sucrose % and sugar yield where their results were appeared medium during both growing seasons. In the same regard, expected genetic advance values showed significant genetic progress in all studied traits during the two growing seasons. As well, highly genetic diversity was obtained between the eight sugar beet accessions through generated 169 amplified fragments from the twelve ISSR primers, 122 of them were polymorphic with 72.18% polymorphism.ConclusionsThe eight sugar beet varieties achieved remarkable and distinctive results for all traits under study during two agricultural years. However, they were differentiated and various from each other. As they differed in their superiority in all estimated traits and they proved to be fertile material for studying in this investigation and very suitable for enriching the breeding and genetic improvement program to promote the sugar beet yield in order to increase the productivity of white sugar in Egypt.

Nuclear and mitochondrial DNA polymorphisms suggest introgression contributed to garden beet (Beta vulgaris L.) domestication

Garden beet is the ancestor of fodder beets and sugar beets, but the origin of garden beet’s genetic potential to evolve novel beet types is debatable. In this study, we analyzed nuclear and mitochondrial DNAs in 47 garden beet accessions using DNA markers. Multiple analytical methods revealed a unified population structure with subpopulations evident in the European and Caucasian accessions. We diagnosed mitochondrial genome types (mitotypes) based on mitochondrial minisatellite loci in 541 plants from the 47 accessions, revealing a major mitotype and 11 minor mitotypes in garden beets from Europe and the Caucasus region that were also present in endemic leaf beets and wild beets. Our data indicate that European and Caucasian garden beets include genetically differentiated subpopulations. Provided that the occurrence of minor mitotypes is a vestige from crosses with leaf beets and wild beets, the notion that introgression contributed to increasing the genetic diversity in the garden beet gene pool is substantiated at the molecular level.

Apomictic lines of sugar beet: development and studying

Background. While working with such cross-pollinated crops as sugar beet, the greatest problem is the fixation of valuable genotypes. Using apomixis to produce breeding material helps to accelerate the breeding process and save the desired combination of genes.Materials and methods. The research objects were 110 accessions of sugar beet from the VIR collection. Field experiments and assessments of the resistance to Cercospora leaf spot, monogermity, and non-bolting were performed according to VIR’s guidelines in 2016–2018 at Pushkin and Pavlovsk Laboratories of VIR and Maikop Experiment Station of VIR. The sugar level in roots was measured using an optical refractometer.Results. A comprehensive study of sugar beet accessions resulted in the development of apomictic lines with cytoplasmic male sterility, followed by an evaluation of their economically important characters. An extremely rare occurrence of biotypes with the 0-type sterility (less than 0.5%) was observed in the population. The seeds obtained from apomixis-prone lines demonstrated a significant difference during inbreeding from the seeds of fertile inbred genotypes: no inbreeding depression was observed in apomictic lines. Lines combining sterility and monogermity in their genotype were produced. Testing parent accessions and apomictic forms did not reveal significant differences in the sugar content and root yield, so the resulting forms can be efficiently used in future breeding programs.Conclusion. Using apomixis to develop sugar beet lines helped to fixate the sugar content level, biennial plant development cycle, and Cercospora leaf spot resistance. Thus, apomixis is promising for ensuring maternal inheritance and preserving the desired combination of genes in sugar beet, thereby accelerating the breeding process.

Analysis of molecular characterizations of beets, Beta vulgaris in response to cyst nematodes, Heterodera schachtii

Sugar beet cyst nematode Heterodera schachtii is a serious biotic limiting factor in sugar beet industry. In this study, 70 sugar beet accessions were screened against H. schachtii, of which 30 resistant and susceptible ones were subjected to polymorphic simple sequence repeat (SSR) marker analysis by seven Universal DNA Amplification (UDA) primer pairs randomly. The results showed a very high significant variation between resistant and susceptible sugar beet accessions in response to H. schachtii with 42 fold increase in nematode reproduction rate in susceptible ones. SSR primers produced 155 bands, out of which 91 ones showed polymorphism, indicating 59% genetic diversity. The highest polymorphic bands was of UDA013 primer with 17 and the lowest one in UDA010 with 10 bands. Average number of polymorphic bands per primer was 13 and per genotype 3.03 bands. The UDA015 had the highest polymorphic index content (PIC) of 80%, and the lowest 44% in UDA001 with the mean of 67%. Highest marker index (MI) was in UDA015 with 10.80, and lowest one 6.48 in UDA001, with the mean of 8.68. Cluster analysis using Numerical Taxonomy and Multivariate Analysis System (NTSYS) software, with UPGMA method based on Jacard's similarity matrix, divided the genotypes into 4 major clusters. The dendrogram was consistent with the clustering result of Principal Component Analysis (PCoA). The highest genetic similarity of 91% was between the genotypes 45 and 51, of which both were offspring of a half-brother and half-sister crossing. The results suggested novel sources of resistant to H. schachtii and that SSR marker is a reliable tool for revealing a high levels of polymorphism among the sugar beet genotypes.

ENVIRONMENTAL AND GEOGRAPHIC STUDY OF BETANIN ACCUMULATION IN PROMISING RED BEET ACCESSIONS FROM THE VIR COLLECTION

Background. Table beet (Beta vulgaris L.) is a source of ‘betanin’, a natural food dye known as food additive E-162. The VIR collection holds a large diversity of red beet accessions. It is the base for obtaining source material to breed cultivars with high betanin content.Materials and methods. In the framework of this study, which lasted from 2015 to 2018, a group of 29 accessions identified during the screening was analyzed. The pigment was assessed at the laboratory of the ECO RESOURCE Joint-Stock Company using Spectrophotometer SF-2000. Field experiments were performed according to VIR’s guidelines in 2015–2017 at Pushkin and Pavlovsk Laboratories of VIR, Volgograd Experiment Station of VIR, and Maikop Experiment Station of VIR.Results. Environmental and geographic tests demonstrated that the ability to accumulate the pigment was variable among the red beet accessions, and its concentrations were notably different. The research showed that accumulation of betanin is primarily associated with agroclimatic growing conditions. The dynamics of pigment accumulation can be both positive and negative. The optimal zone for growing the studied accession is Leningrad Province, where the highest content of betanin was observed. Mid-ripening and cold-resistant old landraces were a reference point in the search for the desired genotypes.Conclusion. The process of pigment accumulation is extremely responsive to weather conditions, soil water balance, and watering uniformity. The negative impact of these factors would smooth down the crop’s varietal polymorphism. Diseases and insect pests have led to slowing and stopping the accumulation of betanin. As a result of the comprehensive agroecological study of prototypes, promising accessions were identified and recommended for cultivation in Leningrad Province with the aim of betanin production.

Comparative characteristics of the biochemical composition of chard and table beet accessions from VIR collection

Relevance. Healthy eating is one of the many steps that lead to a healthy nation. It implies the provision of the human body with all the necessary elements for its normal functioning. Within the framework of import substitution, it is extremely important to identify and popularize valuable crops that are suitable for cultivation in the territory of the Russian Federation. One of these rarely studied and insufficiently studied cultures is the leaf variety of beet –chard (Beta vulgaris L. ssp. сicla). Man uses in the food the fleshy petioles and leaves of this plant.Material and methods. The purpose of the research was to identify the characteristics of the biochemical composition of chard and compare them with the widespread red beet. The object of the study was 44 accessions of red beet (Beta vulgaris L. ssp. vulgaris) and 32 accessions of chard from the VIR collection, differing in phenotype and origin. The accessions were cultivated in the vegetable crop rotation in the Research and production base “Pushkin and Pavlovsk laboratories of VIR” (Pushkin, Leningrad region) for two years (2014 and 2015). Biochemical analysis was performed using standard methods. The quantitative and qualitative composition of the metabolites was assessed using GС-МS (Gas Chromatography-Mass Spectrometry).Results. The results of the study revealed significant variability of indicators depending on the specific genotype. The indicators of the content of ascorbic acid, protein and pigments: betanin in beetroot and β -carotene in leafy can be attributed to slightly varying. A detailed comparative description of the content of carbohydrate profile metabolites is given. It is shown that chard is better balanced in terms of monosaccharides content, differs in low sucrose content. The amino acid composition of chard is richer and more diverse than that of table beet, it is significantly ahead of table beet in essential amino acids for humans. Selected accessions of chard are recommended for use in infant, dietary and diabetic nutrition. Due to the high protein content (83% higher than that of red beet), the culture is recommended as an ingredient for feed production. Leaf beet has a number of valuable advantages: unpretentious in cultivation, decorative and, most importantly, has great potential for use in human nutrition and fodder production.

THE GENE POOL FOR TABLE BEET BREEDING (MODERN ASPECTS OF STUDY AND USE)

Background . Modern production imposes increased requirements to the range of used cultivars, so the development of new cultivars and hybrids most adapted to certain soil and climatic conditions is an important task of breeding. Materials and methods. Table beet accessions from the VIR collection originating from 17 countries were chosen as the material for the present research. The accessions were studied at Pushkin and Pavlovsk Laboratories of VIR, at the Genetic Diversity and Plant Bioresources Center of the All-Russian Breeding and Technological Institute of Horticulture and Nursery (VSTISP) and at Maikop Experiment Station, a branch of VIR, according to VIR’s guidelines. esults. The relationships between earliness, bolting resistance, cold tolerance and resistance to black root have been established. The majority of the studied accessions had medium resistance to black root. The cultivars ‘Asmer Detroit 72’ (k-3113, Great Britain), ‘Bravo’ (k-3047, Russia) and ‘Podzimnyaya A-474’ (k-1678, Russia) distinguished by resistance to black root, were also characterized by cold tolerance and stable productivity. The differences in bolting resistance among the accessions were found to depend on their origin. The cultivars from Sweden, Finland and from the Russian Northwest were most resistant to bolting. The early accessions ‘Perfected Detroit Dark Red’ (k-1815, Canada), ‘Bikor’ (k-2873, the Netherlands), ‘Severnyshar’ (k-1586, Russia) and ‘Polyarnaya ploskaya’ (k-1585, Russia) were characterized by high rates of the vegetative mass growth and bolting resistance. It was noted that the absolutely monogermic varieties have lower ripening rates, productivity, and resistance to bolting, compared to the multigerm ones, but have similar chemical composition indicators and root quality. Accessions with a wide distribution area that maintain high root productivity at 115–120% to the reference in different climatic conditions have been identified. Conclusions. The research has resulted in the identification of table beet accessions characterized by a complex of biological and economically important traits. The relationships between earliness, resistance to bolting and cold tolerance have been revealed. Genetic sources of monogermicity, bolting resistance, cold tolerance, black root resistance and high root quality are recommended for the use in breeding.

GENOTYPIC VARIATIONS IN SALT TOLERANCE OF SOME EGYPTIAN WILD BEET ACCESSIONS

This study reports for the first time the eco-physiological responses of some Egyptian wild beet accessions (WB1013, WB1021 and WB1026) under saline irrigation. The plants were exposed to five seawater salinities (0, 20, 30, 40 and 60% sws) for 6 weeks in a sandy culture in the greenhouse. Low salinity (20% sws) slightly enhanced the plant fresh weight of both WB1013 and WB1021 genotypes by 5% and 3% respectively, but significantly reduced that of WB1026 genotype by about 10%. Higher seawater salinities, however, caused progressive growth reductions in all accessions, with maximum growth inhibition, being 59% in WB1026 at 60% sws. Tolerance threshold was lowest (being at 20% sws) for WB1026, but highest (reached 40% sws) for both genotypes WB1013 and WB1021. EC50 was at salinity level of 40 – 60% sws for WB1026 genotype, but higher than 60% sws for genotypes WB1013 and WB1021. These indicate that both accessions WB1013 and WB1021 are more salt-tolerant when compared with WB1026. The higher salt tolerance of WB1013 and WB1021 accessions is largely conferred by higher leaf K+/Na+ ratio, due to low Na+ and Cl- accumulation under saline conditions compared to WB1026. This was associated with lower dry weights and ion leakage, and with higher leaf area, chlorophyll readings, total soluble carbohydrates and Ca2+ concentrations when compared with WB1026. Both WB1013 and WB1021 accessions do not only offer the possibility of being an alternative promising cash crops under seawater irrigation, but also, through an understanding of its physiology, may provide possible routes to enhance salt tolerance in other beet crops.