Advances in Cereal Crops Breeding

Cereals are the main food and feed crops on our planet, with wheat, rice, and maize occupying three-quarters of the total acreage [...

Wheat, Barley, and Oat Breeding for Health Benefit Components in Grain

Cereal grains provide half of the calories consumed by humans. In addition, they contain important compounds beneficial for health. During the last years, a broad spectrum of new cereal grain-derived products for dietary purposes emerged on the global food market. Special breeding programs aimed at cultivars utilizable for these new products have been launched for both the main sources of staple foods (such as rice, wheat, and maize) and other cereal crops (oat, barley, sorghum, millet, etc.). The breeding paradigm has been switched from traditional grain quality indicators (for example, high breadmaking quality and protein content for common wheat or content of protein, lysine, and starch for barley and oat) to more specialized ones (high content of bioactive compounds, vitamins, dietary fibers, and oils, etc.). To enrich cereal grain with functional components while growing plants in contrast to the post-harvesting improvement of staple foods with natural and synthetic additives, the new breeding programs need a source of genes for the improvement of the content of health benefit components in grain. The current review aims to consider current trends and achievements in wheat, barley, and oat breeding for health-benefiting components. The sources of these valuable genes are plant genetic resources deposited in genebanks: landraces, rare crop species, or even wild relatives of cultivated plants. Traditional plant breeding approaches supplemented with marker-assisted selection and genetic editing, as well as high-throughput chemotyping techniques, are exploited to speed up the breeding for the desired genotуpes. Biochemical and genetic bases for the enrichment of the grain of modern cereal crop cultivars with micronutrients, oils, phenolics, and other compounds are discussed, and certain cases of contributions to special health-improving diets are summarized. Correlations between the content of certain bioactive compounds and the resistance to diseases or tolerance to certain abiotic stressors suggest that breeding programs aimed at raising the levels of health-benefiting components in cereal grain might at the same time match the task of developing cultivars adapted to unfavorable environmental conditions

Long-Term Storage and Longevity of Orthodox Seeds: A Systematic Review

As part of conservation of plant genetic resources, long-term storage of seeds is highly relevant for genebanks. Here we present a systematic review and a meta-analysis of studies on seed longevity focusing on half-life (P-50) under different storage conditions. Six studies were selected for the meta-analysis; in addition, a high number of additional references were included in the discussion of the results. The results show that under ambient conditions, half-life is short, from 5 to 10 years, while under more optimal conditions, which for orthodox seeds is at low humidity and low temperature, half-life is more in the 40-60 years range, although with large interspecies variation. Under long-term genebank conditions, with seeds dried to equilibrium and thereafter kept at minus 18-20 degrees C in waterproof bags or jars, half-life can be twice or three times as long. In general, many of the grain legume seeds, as well as corn, common oat, and common barley are long-lived, while cereal rye, onion, garden lettuce, pepper, and some of the forage grasses are more short-lived. Conditions during maturation and harvesting influence longevity, and proper maturation and gentle handling are known to be of importance. Seed longevity models have been developed to predict final germination based on initial viability, temperature, humidity, storage time, and species information. We compared predicted germination to results from the long-term experiments. The predicted values were higher or much higher than the observed values, which demonstrate that something in the seed handling in the genebanks have not been optimal. Long-term studies are now available with data at least up to 60 years of storage. Our review shows that the knowledge and methodology developed for the conservation of plant genetic resources should also work for wild species of orthodox seed nature

The Impact of N.I. Vavilov on the Conservation and Use of Plant Genetic Resources in Scandinavia: A Review

In this review we examine Nikolai Ivanovich Vavilov’s relationship to Scandinavia and the impact he and his ideas have had on Scandinavia. We trace the historical connections from Vavilov back to 18th century scientists, such as Carl Von Linneaus (Sweden) and 19th century European scientists such as Alphonse de Candolle (Switzerland), Henry de Vilmorin (France), and William Bateson (England). Vavilov has influenced the conservation work in Scandinavia resulting amongst other in the establishment of the Nordic Gene Bank in 1979 and the Svalbard Global Seed Vault which started operating in 2008. Vavilov travelled to Scandinavia in 1921 and in 1931 to give lectures and exchange ideas, especially with the breeders at the Swedish Seed Association (Svalöf) in Scania, Sweden, but also at the Copenhagen University in Denmark. Vavilov did not recognize Scandinavia as part of a center of origin of cultivated plants. It was only after World War II, when P.M. Zhukovsky, a scholar of N.I Vavilov, developed the concept of mega-centers of diversity of cultivated plants, that Scandinavia became part of what he termed the European-Siberian Region of Diversity. We list species domesticated in Scandinavia or Northern Europe, and we further discuss concepts related to crop evolution and highlight the great impact Vavilov has had by inspiring scientists across disciplines and over many decades

Long-Term Analysis of the Variability of Agronomic Characters in the VIR Oat Germplasm Collection in Central Black Soil Region of Russia

Climate change has become a significant factor in crop production in the 21st century for many countries. To turn losses into profit, adaptation measures are needed, which are based on the analysis and forecast of economically valuable characteristics of crops. The field trial data were analyzed for 764 oat accessions from the global germplasm collection by the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) in 2001–2019 and the cultivar ‘Gorizont’ in 1990–2019 in Yekaterinino Experiment Station of VIR (Tambov Province, Russia, 52°59′ N, 40°50′ E). A progressive shortening of the growing season and a yield increase were observed during the study both in the mean values for the tested accessions and in the cv. ‘Gorizont’. Grain yield variability of cv. ‘Gorizont’ across the years was also associated with 1000 grain weight variations. The models predict a further reduction in the growing season by 2.4 days/10 years, mainly caused by an increase in temperatures above 15 °C, and an increase in yield by 47.6 g/m2/10 years, mainly caused by an increase in the temperature in May. ANOVA demonstrated that the highest yields in Tambov Province were produced by accessions from Ulyanovsk Province, Ukraine, Moscow Province, Norway, Germany, and Poland

Origin of Wild Polyploid <i>Avena</i> Species Inferred from Polymorphism of the ITS1 rDNA in Their Genomes

In this article, we analyzed the origin of wild polyploid oats (Avena L., Poaceae) using the region 18S rDNA (partially)–ITS1–5.8S rDNA obtained via NGS. There are six tetraploid (2n = 28) and four hexaploid (2n = 42) wild species differing by specific genome combinations: A. barbata, A. vaviloviana (AB), A. agadiriana (AB or BB), A. magna, A. murphyi, A. insularis (AC or CD), A. ludoviciana, A. sterilis, A. fatua, and A. occidentalis (ACD). We compared the pool of marker sequences of polyploid oats with those of their putative diploid ancestors: A. atlantica (As-genome), A. hirtula (As), A. canariensis (Ac), A. ventricosa (Cv), and A. clauda (paleopolyploid with Cp and A-related rDNA). We found 15 major ribotypes (more than 1000 reads per rDNA pool) in polyploid oats. Comparing them, we found that the AB-tetraploid oats possibly inherited their A-genome ribotypes from A. atlantica (As1-ribotype), whereas their B-genome ribotype is specific and can be a derivative of the A-genome family. Our data do not support the hypothesis of the CD-genome set in A. magna, A. murphyi, and A. insularis: they have an AC-genome ribotype constitution instead. The C-genome-related sequences could have been obtained from A. ventricosa. Hexaploids show a different ribotype pattern than tetraploids; the main ribotypes of A. fatua, A. ludoviciana, and A. sterilis probably belong to the D-group and are also shared with one of the major ribotypes of A. clauda

Evaluating Germplasm of Cultivated Oat Species from the VIR Collection under the Russian Northwest Conditions

Oat is one of the most widespread and important cereal crops in the global agricultural production. Searching for new high-yielding and nutritious forms continues to be relevant, especially under the global trend of climate change, when most local oat cultivars may become economically inefficient. Spring oat accessions from VIR collection served as the material for this study; their origin is diverse, as they came from 11 countries. The basic nutritional value (the content of protein, oil, starch, and β-glucans) and characters important for breeding (plant height, panicle length, number of spikelets, number of grains per panicle, 1000 grain weight, and grain yield) were analyzed in 49 accessions of the cultivated covered oat species: Avena sativa L., A. strigosa Schreb., A. abyssinica Hochst., and A. byzantina Coch., grown under the conditions of the Russian Northwest (Leningrad Province) for two years. Variability parameters, interspecific and intervarietal differences, and the effect of weather conditions were assessed. Sources of useful agronomic traits were identified; they can be used to expand the range of the source material for the development of new high-yielding and highly nutritious oat cultivars adapted to local cultivation conditions. It is demonstrated that the VIR collection has a great potential for contemporary food and feed production and for the breeding of new oat cultivars for various purposes. Thus, the contribution of Nikolai Vavilov to the plant genetic resources investigation for the benefit of humanity is invaluable

New Insights into the Genomic Structure of Avena L.: Comparison of the Divergence of A-Genome and One C-Genome Oat Species

We used next-generation sequencing analysis of the 3&prime;-part of 18S rDNA, ITS1, and a 5&prime;-part of the 5.8S rDNA region to understand genetic variation among seven diploid A-genome Avena species. We used 4&ndash;49 accessions per species that represented the As genome (A. atlantica, A. hirtula, and wiestii), Ac genome (A.&nbsp;canariensis), Ad genome (A. damascena), Al genome (A. longiglumis), and Ap genome (A. prostrata). We also took into our analysis one C-genome species, A. clauda, which previously was found to be related to A-genome species. The sequences of 169 accessions revealed 156 haplotypes of which seven haplotypes were shared by two to five species. We found 16 ribotypes that consisted of a unique sequence with a characteristic pattern of single nucleotide polymorphisms and deletions. The number of ribotypes per species varied from one in A. longiglumis to four in A. wiestii. Although most ribotypes were species-specific, we found two ribotypes shared by three species (one for A. damascena, A. hirtula, and A. wiestii, and the second for A. longiglumis, A. atlantica, and A. wiestii), and a third ribotype shared between A. atlantica and A. wiestii. A characteristic feature of the A. clauda ribotype, a diploid C-genome species, is that two different families of ribotypes have been found in this species. Some of these ribotypes are characteristic of Cc-genome species, whereas others are closely related to As-genome ribotypes. This means that A. clauda can be a hybrid between As- and C-genome oats