Seed Bank Research Articles

Conserving orthodox seeds of globally threatened plants ex situ in the Millennium Seed Bank, Royal Botanic Gardens, Kew, UK: the status of seed collections

We reviewed the status of orthodox seed collections of globally threatened plants conserved in − 20 °C long-term storage at the Millennium Seed Bank, Royal Botanic Gardens, Kew, UK in terms of their geographic and bioclimatic representativeness, taxonomic and genetic diversity, quality and physiological status. The comprehensive dataset used spans over 45 years of worldwide conservation effort across various organisations. The data provides evidence-based results and future directions for the represented globally threatened flora that are of relevance to all plant conservation and seed banking organisations across the globe. The reviewed sample includes 523 collections and represents a wide geographic range, originating from 67 countries, from all nine bio-geographic continents. The majority of collections originated from temperate climates and from habitats with no dry seasons but experiencing warm summer periods. The taxonomic composition of the collections highlighted a substantial diversity, with 303 taxa (four extinct in the wild; 56 critically endangered; 105 endangered; and 138 vulnerable) represented by 297 species, 199 genera and 74 families. Almost four fifths of the collections were harvested from wild habitats. Whilst wild-origin collections can harbour useful genes not available in the cultivated gene pool, for threatened plants both collections and taxa are likely to suffer from low genetic diversity as a low number of individual plants, populations and/or potentially viable or usable seeds were sampled at the original harvest. Large numbers of empty and infested seeds in the original harvest have significantly affected the quality of collections in terms of availability of potentially viable or usable seeds in collections. As a result, just over one third of taxa and one fifth of collections consisted of ≥ 5000 potentially viable or usable seeds. Viable seeds exhibited a sound physiological status in terms of germinability and viability at the initial round of germination tests after storage, but on average, relative germination and viability achieved were below 85%. A decline in germinability during their variable time of storage was evident for 16% of the 78 collections analysed for longevity. According to a set of criteria, suitable germination protocols for propagation of plants from seeds were identified for 165 taxa. Given the apparent differences between wild species, especially those that are rare and threatened, and domesticated crops, the quality and physiological status of reviewed collections are reasonably sound. The characteristics we observed for collections, the challenges we identified for conserving them and the germination protocols we suggested for propagation of plants from seeds have the scope to be noted, integrated and used globally across various conservation activities and policies.

Research Progress on Soil Seed Bank: A Bibliometrics Analysis

The soil seed bank (SSB) is a natural bank of viable seeds in the soil or on its surface. Researches on SSB have accumulated extensively worldwide, but have seldom been visualized and quantitatively analyzed. In this paper, publications related to SSB from 1900 to 2019 were collected from the Web of Science Core Collection database, and reviewed and analyzed using CiteSpace. Annual publications distribution, co-occurrence analysis, collaboration network analysis, co-citation analysis and burst detection were all conducted. The results showed that (1) the number of SSB publications had increased rapidly and is still a hotspot; (2) SSB study is an interdisciplinary field mainly concentrated in ecology, environmental science, and plant science; (3) close research cooperation occurred among European countries which were more influential, whereas the USA was the most active country; (4) soil seed genetic diversity, seed persistence, seed trait, restoration potential and restoration projects, and spatial and temporal variation were the main research areas. (5) R language and linear mixed effects models are currently popular in SSB research. Invasive species, weed control, restoration potential and restoration projects, seed traits (especially seed longevity and dormancy), and SSB responses to environment changes (especially climate change and fire) are newly emerging trends in the research.

The Role of Vegetable Genetic Resources in Nutrition Security and Vegetable Breeding

Malnutrition, comprising undernutrition, micronutrient deficiency, and overnutrition, is more widespread than hunger per se and affects most nations around the globe. The diversity and the quality of food produced and consumed are decisive factors when addressing the triple burden of malnutrition. In this context, fruit, vegetables, and nuts are increasingly moving into the focus of the nutrition community. Agricultural policies and investments in agriculture are predominantly focused on staple food production, neglecting the economic and nutritional potential of fruit and vegetables. While global vegetables are well represented in genebanks around the globe, this is much less the case for traditional vegetables. Collecting efforts in hotspots of vegetable diversity in Africa and Asia are required to conserve this germplasm before it is being replaced by modern varieties. Home gardens, community seedbanks, and variety introduction through vegetable seed kits are ways how genebanks can link with the farming community to strengthen the informal seed sector. This in turn may result in more diverse production systems and increased consumption of fruit and vegetables. In the formal seed sector, vegetable breeders need access to a wide diversity of genetic resources, predominantly farmers’ varieties, landraces, and crop wild relatives. Genomics-assisted breeding is increasingly facilitating the introgression of favorable genes and quantitative trait loci (QTLs) with complex inheritance patterns from wild species into cultigens. This will lead to wider use of crop wild relatives in the development of resilient cultivars.

The past shall not begin: Frozen seeds, extended presents and the politics of reversibility

The article analyzes the Svalbard Global Seed Vault (SGSV) as a specific security technology created to deal with the ecological threat of biodiversity loss. Built in 2008 inside the Arctic Circle, the SGSV serves as a backup for 1,700 agricultural gene banks around the world. If seed collections are lost due to natural disasters or human error, the gene banks can request copies of their varieties from Svalbard and restore their collections to continue the endeavour of plant breeding. The article focuses on the particular temporal politics expressed in the SGSV. Drawing on Niklas Luhmann’s reflections on time, it is argued that the SGSV opens up the possibility of reversing events by expanding the duration of the present. By separating seeds from their ecological connections on the one hand and controlling their metabolic processes through the use of cold on the other, an enduring temporal zone is created that allows modern society to control the unpredictable and irreversible dynamics of life and undo its emergent effects. The SGSV therefore materializes what is herein called the politics of reversibility.

Exploring seed longevity of UK native trees: implications for ex situ conservation

AbstractUK trees require increased conservation efforts due to sparse and fragmented populations. Ex situ conservation, including seed banking, can be used to better manage these issues. We conducted accelerated ageing tests on seeds of 22 UK native woody species, in order to assess their likely longevity and optimize their conservation in a seed bank. Germination at four ageing time points was determined to construct survival curves, and it was concluded that multiple samples within a species showed comparable responses for most species tested, except for Fraxinus excelsior. Of all species studied, one could be classified as very short-lived, four as short-lived and 17 as medium, with none exceeding the medium category. The most important finding of this manuscript is that although some taxonomic trends were observed, the results indicate the need for caution when making broad conclusions on potential seed storage life at a species, genus or family level. Longevity predictions were compared to actual performance of older collections held in long-term storage at the Millennium Seed Bank, Kew. Although most collections remain high in viability in storage after more than 20 years, for short-lived species at least, there is some indication that accelerated ageing predicts longevity in seed bank conditions. For species with reduced potential longevity, such as Fagus sylvatica and Ulmus glabra, additional storage options are recommended for long-term gene banking.

Lessons learned as Erica turgida is returned

Erica turgida, a small unassuming pink bushy heath species was listed as ‘Extinct in the Wild’ in 1996. It was last seen in habitat at Kenilworth Racecourse by South African botanist, Elsie Esterhuizen who made an herbarium collection and gave material for propagation to Kirstenbosch Botanical Garden. It once occurred in small patches on the lowlands around the city of Cape Town now commonly known as the Cape Flats. However, colonial agricultural settlements, and more recently industrial development and urban expansion, have led to the decline and ultimate loss of this species in the wild. Erica turgida has since then been kept from extinction by Kirstenbosch horticulturists and the Millennium Seed Bank Project. Fortuitously, a second collection was found in the collections of the Belvedere Palace Garden in Vienna and returned to South Africa in 2001. Its re-introduction to the remaining conserved natural areas of Cape Flats Sand Fynbos, a Critically Endangered vegetation type, proved challenging as it is a relatively short-lived species and no definitive record exists of its preferred niche habitat. Early attempts to reintroduce Erica turgida at Kenilworth Racecourse Conservation Area and Rondevlei Nature Reserve failed however limited success has been achieved at Tokai which is under the management of the South African National Parks. This paper shows how over a period of 30 years this Erica species has been propagated from cuttings, planted in numerous micro habitats and monitored for survival and recruitment. General protocols for placement of plants and timing of restoration have also been developed and are explained in this paper. This work has contributed towards the Global Strategy for Plant Conservation targets 4, 5, 7, 8, 14 and 16 for the South African National Biodiversity Institute and Royal Botanic Gardens Kew.

Evaluation of varieties and local forms of winter garlic for their economic characteristics in the conditions of right bank Forest Steppe of Ukraine

Garlic production for the local market and for export lacks a suffi cient amount of high-yielding varieties with large bulbs and small amount of cloves, resistant to pests, diseases and stressful cultivation conditions. In addition to industrial varieties, adapted local forms of self-breeding are currently cultivated. Winter garlic is a plant with vegetative reproduction and it is reproduces with cloves, single clove and air bulbs, Therefore, the varieties brought from other regions degenerate quickly. Two and three times reproduction leads to a gradual reduction in yield and quality. The transfer of local forms from one region to another requires further study. Researches were carried out in conditions of right bank Forest Steppe of Ukraine. We studied 60 samples of winter garlic. The working collection of winter garlic was composed of varieties and local forms brought from Kyiv, Chernihiv, Dnipropetrovsk, Kirovograd and Cherkassy regions. Some samples (45 pcs.) were received from the National Center of Plant Genetic Resources of Ukraine. The variety of Prometey created at Uman University of gardening was used as the control. The research was conducted according to the "Methods of experimental work in vegetable growing and melon-plot fi eld" (G. L. Bondarenko, K. I. Yakovenko, Kharkiv 2001). The plants density was 340 thousand plants ha. On the average for 2017-2020 the heads formed the largest diameter in the variants of IOB00003-Biryuchekutskiy local (55 mm) and IOB00117 (53 mm). Their average weight was the highest in the sample of IOB00117 – 41 g. The smallest heads were formed in the variant of IOB00083 Spas – 17 g. Essentially higher yield of heads of winter garlic was collected from cultivation of plants of the variant IOB00117 – 12,6 t/ha. The greatest share of commodity heads was observed for samples IOB00003-Biryuchekutskiy local and IOB00117 (92 %). Thus, samples of IOB00003-Biryuchekutskiy local and IOB00117 were the best in the diameter, weight of a head and productivity among the samples studied in the research carried. They yielded 9.6 and 12.6 t/ha, respectively, with head weights of 31 and 41 g and the diameter of 55 and 53 cm. Key words: varieties, local forms, collection, winter garlic, weight of the bulb, marketability.

Weed Flora and Soil Seed Bank Composition as Affected by Tillage System in Three-Year Crop Rotation

In recent years, there has been an increasing interest around agricultural science and practice in conservation tillage systems that are compatible with sustainable agriculture. The aim of this study was to assess the qualitative and quantitative changes in weed flora and soil seed bank under reduced tillage and no-till (direct sowing) in comparison with traditional ploughing. In the crop rotation: pea/rape—winter wheat—winter wheat the number and dry weight of weeds increased with the simplification of tillage. The seed bank was the largest under direct sowing and about three times smaller in traditional ploughing. Under direct sowing, most weed seeds were accumulated in the top soil layer 0–5 cm, while in the ploughing system most weed seeds occurred in deeper layers: 5–10 and 10–20 cm. In the reduced and no-till systems, a greater percentage of perennial and invasive species, such as Conyza canadensis L., was observed. The results show that it is possible to maintain weed infestation in the no-till system at a level that does not significantly affect winter wheat yield and does not pose a threat of perennial and invasive weeds when effective herbicide protection is applied.

Doomsday Scenario: How We Should Prepare to Be Able to Rebuild Our Civilization Faster in Case of Full Catastrophe

We have built the Global Seed vault (also known as Doomsday vault) at Spitsbergen, part of Norway’s Svalbard archipelago to ensure the future of humanity in case of catastrophe caused by pandemic or nuclear war. There are discussions how we can bring back the civilization using the plough that kick started our civilization. This paper proposes how we can bring back the civilization faster by safekeeping all the patents, formulas, and important theories that have shaped our economy and way of life through global consortium which we must establish to secure the future of humanity.

Single nucleotide polymorphisms in GBBSI and SSIIa genes in relation to starch physicochemical properties in selected rice (Oryza sativa L.) varieties

Single nucleotide polymorphisms in GBBSI and SSIIa genes in relation to starch physicochemical properties in selected rice (Oryza sativa L.) varieties

News from the Australian Seed Bank Partnership: Restoration of native wildflower patches in agronomic settings for diverse and healthy pollinator populations

News from the Australian Seed Bank Partnership: Restoration of native wildflower patches in agronomic settings for diverse and healthy pollinator populations

Do community seed banks contribute to the social-ecological resilience of communities? A case-study from western Guatemala

ABSTRACT Community seed banks (CSBs) are initiatives to support the conservation and use of diverse crops though locally rooted collective action. The impact of CSBs is assumed to be complex, but has not been investigated in detail. Our study addresses this gap by analysing the impact of CSBs using social-ecological resilience as theoretical framework. We focus on the western highlands of Guatemala where CSBs have been implemented since 2009. We used qualitative and quantitative methods of data collection and analysis, including focus groups, participatory workshops, and structured and semi-structured interviews conducted in the local communities with CSB members and non-members. Our results indicate that CSBs contributed to increased seed exchanges, improved access to novel crop diversity, more saving of traditional varieties, and greater information and knowledge access, use and exchange. These effects strengthened the social-ecological resilience of the local communities. The scope of action of the CSBs, however, was constrained by wider socio-economic trends, including social divisions, out-migration of youth, and a change in livelihood strategies. We conclude that for CSBs to effectively strengthen social-ecological resilience in the future, they should be continuously adapted to the local context. Conceptually, our findings call for the further evolution of the CSB concept.

Spatial Distribution of Weed Seed Banks in the Agricultural Field and Anthropized Cerrado

Characterization of the seeds bank is an essential tool for decision making on weed control and management practices and the study and maintenance of the ecological dynamics of natural areas. In this context, the present study aimed to characterize the spatial variability of the seeds bank in an experimental agricultural field and an anthropized cerrado area, using the ordinary kriging geostatistical technique. Sampling was carried out on 10x10 regular grids in two different environments. Area 01 consisted of an experimental agricultural field of annual crops (soy and corn); area 02 represented the anthropized cerrado. The sample grids consisted of 25 points collected at a depth of 0.00-0.20 m. The soil samples were placed in 6.38 dm3 and 0.05 m² plastic containers. Spatial distribution maps of the species found have been drawn up, grouped in dicotyledonous, monocotyledonous, and total density, in addition, the density of three weeds most found in each area. The weed seed bank present strong spatial variability to 01 and 02, which indicates behavior in spots or in patches for both dicotyledonous and monocotyledonous plants, especially Mollugo verticillata L. and Eleusine indica (L.) Gaertn. in the experimental field, and for Richardia scabra L. and Eleusine indica (L.) Gaertn. in the anthropized cerrado. The ordinary kriging technique made it possible to map the weed seed bank and, therefore, it may work as an efficient tool in controlling weeds in agricultural fields, especially in its pre-emergence phase. Furthermore, it can assist in the recovery of native anthropized vegetation.

Seed banks in urban vacant lots of a Latin American megacity are easily germinable and strongly dominated by exotic flora

Seed banks in the soil play a role in the temporal continuity and succession of vegetation in urban vacant lots. Therefore, it is necessary to know the composition, abundance and dynamics of the seeds stored in the lots’ soils to understand their effect on spontaneously established urban plants. We hypothesized that soil seed banks in the urban vacant lots of Santiago, Chile, have a high abundance of seeds and an easily germinable bank of mainly exotic annual weeds. Additionally, 5 drivers (lot age, lot area, distance to urban centre, distance to urban boundary, and population density) were associated with the density of seed banks in the soil of urban lots. In 20 lots studied, 18 soil samples (150 cm3 per sample) were collected, 9 samples at a depth of 0–5 cm, and 9 samples at >5–10 cm. This seed bank was studied by seed germination in each of the soil samples. Thirty-eight species recorded in the seed banks were exotic (83.7% were European, Mediterranean or Eurasian) and only three native. Two species could be identified up to genus only. We recorded in total 2934 seedlings in the upper soil layer and 506 seedlings in the lower soil layer from the 20 lots analyzed. The species frequency in the upper seed bank was positively and significantly correlated with the frequency of the lower seed bank and with species frequency for above-ground vegetation. In the upper soil layer, our results showed that smaller lots located in the most densely populated neighborhoods contain more weed seed density in the soil than greater lots located in less densely populated areas. The rest of the factors evaluated were not associated with the density of the seed banks in the soil. The results indicate that research in seed banks in urban habitats should be expanded and deepened, since the seed banks are determinants in the spatio-temporal abundance and diversity of above-ground spontaneous urban lot flora.

Specificity of potential contamination of rice checks with weed seeds

Goal. To analyze the potential level of contamination of arable soil layer weed seeds and to establish the specificity of the changes in such reserves during the vegetation period of crops. The study was performed on rice checks of the Institute of rice of NAAS in the Kherson region in the 2017—2019 biennium.
 Methods. Research field, small and laboratory. To determine the factor of seeds and vegetative reproductive organs of weeds in certain soil horizons of rice fields per unit area (pieces/m2) was selected soil samples by the method of A. N. Kiseleva — twice per season, in spring and after harvest of rice. The arable soil was divided into three layers (10 cm each). To determine the viability of seeds used method of staining their tetrazoles. The results were compiled and analyzed.
 Results. A comparison of the level of potential contamination between horizons showed the highest number of weed seeds in the horizon of 0—10 cm on average, 16041 pieces/ m2, which is 47.6% of the overall presence of weeds in the soil (33650,2 pieces/ m2). In the soil horizon 10—20 cm the number of weed seeds reached 10489.2 pieces/m2, or 31.2% of the debris of the upper horizon. In the lower horizon of 20—30 cm level of the presence of weed seeds was low — 7119.8 pieces/ m2, which amounts to 21.2% from that of the top horizon of the soil. Among the weed species whose seeds were present in soil samples of the top horizon of 0—10 cm, the largest part was Kuga Astrakhantseva Scirpus mucronatus L. — 59.8%, in another place Boule seeds Kuga razveseloj Scirpus supinus L. — 31.8%, Polygonum Persicaria hydropiper L. percetage — 1004.7 pieces/ m2 (6,3%), chicken millet Echinochloa crus galli L. — 329.1 pieces/m2 (2.1%). Other types were less in the stocks of weed seeds.
 Conclusions. During the vegetation period inventory quantities of seeds of change and by autumn are increasing. The largest amplitude value of the stock of weed seeds is manifested in the upper 0—10 cm horizon of the arable layer and reaches to 12.3%. Qualitative and timely implementation of measures to protect rice crops from sowing to the presence of weeds provides a gradual reduction in the volumes of their Bank of seeds in the soil.

Agrobiodiversity and its Conservation in Nepal

Nepal is a part of the world’s biodiversity hotspot and ranks the 49th in the world for biodiversity. Agrobiodiversity and its conservation status were studied through literature review, field survey, key informant survey and focus group discussion. Results of field implementation of some good practices and action research were also documented. Among 24,300 total species in the country, 28% are agricultural genetic resources (AGRs), termed as agrobiodiversity. Agrobiodiversity has six components (crops, forages, livestock, aquatic, insects and microorganisms) and four sub-components (domesticated, semi-domesticated, wild relatives and wild edible) in Nepal. Agrobiodiversity on each component exists at agroecosystem, species, variety/breed/biotype/race/strain, genotype and allele levels, within an altitude range from 60 to 5,000 masl. There are 12 agroecosystems supporting 1026 species under crop component, 510 under forage, 35 under livestock, 250 under the aquatic animal, 17 under aquatic plant, 3,500 under insect and 800 under microorganism. An estimated loss of agrobiodiversity is 40%, however, farmers have reported up to 100% loss of AGRs in some areas for a particular species. Conservation of agrobiodiversity has been initiated since 1986. Four strategies namely ex-situ, on-farm, in-situ and breeding have been adopted for conservation and sustainable utilization of AGRs. Eighty good practices including process, methods and actions for managing agrobiodiversity have been in practice and these practices come under five conservation components (sensitization, method and approach, accelerator, value and enabling environment). Within the country, 18,765 accessions of AGRs have been conserved in different kinds of banks. A total of 24,683 accessions of Nepalese crops, forages and microbes have been conserved in different international and foreign genebanks. Some collections are conserved as safety duplication and safety backup in different CGIARs’ banks and World Seed Vault, Korea. Two global databases (GENESYS and EURISCO) have maintained 19,200 Nepalese accessions. Geographical Information System, Climate Analog Tool and biotechnological tools have been applied for better managing AGRs. Many stakeholders need to further concentrate on the conservation and utilization of AGRs. Global marketing of some native AGRs is necessary for sustaining agriculture and attracting young generations as well as conserving them through use.

Factors at Multiple Scales Influence Recruitment from Herbaceous Wetland Seed Banks in the Lower Mississippi Alluvial Valley

In early successional stages, seedlings serve as a link between past and future wetland plant assemblages. Our objectives were to 1) enumerate seedling density in soil exposed to various hydrologic treatments 2) determine similarities between standing vegetation, germinated seedlings, and early successional stage assemblages, and 3) better understand effects of landscape-level factors on overall wetland seedling density. Soil samples were collected and standing vegetation characterized from 12 restored and three non-managed wetlands in the Mississippi River Alluvial Valley (MAV). Seedling germination was observed in a greenhouse experiment, while early-stage plant assembly was followed in outdoor mesocosms. Hydrology significantly affected seedling density, with constantly moist treatments increasing seedling germination above that observed in fluctuating or continually inundated treatments. Standing vegetation in MAV wetlands differed from germinated seedlings; however, germinated seedlings were similar in terms of structure and identity to early successional mesocosm assemblages, indicating close linkages of these two vegetation stages. When landscape-level factors were examined, we found that wetland size was positively correlated, and surrounding land use and watershed nitrogen (N) loading negatively correlated with seedling numbers. Thus, seedling dynamics were affected by factors internal and external to wetlands, necessitating landscape-scale perspectives when making management decisions, even for individual wetlands.

Potential of Soil Seed Bank and Ungulate-mediated Endozoochory in Old Field Restoration

Potential of Soil Seed Bank and Ungulate-mediated Endozoochory in Old Field Restoration

Changes in the Weed Seed Bank in Long-Term Establishment Methods Trials under Rice-Wheat Cropping System

The rice–wheat cropping system in the Indo-Gangetic Plains is the backbone of food security in India. In the 1990s, due to the scarcity of resources, the traditional Crop Establishment (CE) method shifted from Conventional Till Puddle Transplanted Rice (CTPTR) to CT Direct Seeded Rice (CTDSR) and Zero-Till DSR (ZTDSR) in paddy; and in wheat, from Conventional Till Wheat (CTW) to Zero Till Wheat (ZTW), with residue retention in rice (RRR) or in both rice and wheat (RRRW). Shift in CE methods led to change in Weed Seed Bank (WSB) dynamics and ultimately affected the weed management program. After five years of field trials, soil samples were drawn as per 2-factors factorial randomized block design. Factor-I comprised 4-CE methods, whereas factor-II consisted of 3-soil depths (0–10, 10–20 and 20–30 cm). Results showed CTPTR-CTW and ZTDSR-ZTW (RRRW) record the highest seed bank (SB) of grasses, sedges and BLWs as total weeds, in general; and predominant weeds like Echinochloa spp., Ammania baccifera, Commelina benghalensis and Digitaria sanguinalis, in particular. It also showed the higher species richness (DMg) and Shannon–Weaver (H’) indices. CTDSR-CTW and CTDSR-ZTW (RRR) show the lowest WSB and at par with Shannon–Weaver (H’) index; further, lowest species richness (DMg) under CTDSR-CTW. Species Evenness (J’) and Simpson index (λ) vary non-significantly with CE methods. Furthermore, 0–10 cm soil depth showed the highest SB of different category of total weed, predominant weeds as well as higher values of DMg, H’, and λ; whereas reverse trend was observed in Whittaker Statistic (βW). Interaction between CE methods and soil depth revealed most of WSB lying on the top layer in case of ZTDSR-ZTW (RRRW) and CTDSR-ZTW (RRR); while CTPTR-CTW showed almost uniform WSB distribution, and in case of CTDSR-CTW, a gradual decrease in WSB with soil depth.

Genomic analysis of Spanish wheat landraces reveals their variability and potential for breeding

BackgroundOne of the main goals of the plant breeding in the twenty-first century is the development of crop cultivars that can maintain current yields in unfavorable environments. Landraces that have been grown under varying local conditions include genetic diversity that will be essential to achieve this objective. The Center of Plant Genetic Resources of the Spanish Institute for Agriculture Research maintains a broad collection of wheat landraces. These accessions, which are locally adapted to diverse eco-climatic conditions, represent highly valuable materials for breeding. However, their efficient use requires an exhaustive genetic characterization. The overall aim of this study was to assess the diversity and population structure of a selected set of 380 Spanish landraces and 52 reference varieties of bread and durum wheat by high-throughput genotyping.ResultsThe DArTseq GBS approach generated 10 K SNPs and 40 K high-quality DArT markers, which were located against the currently available bread and durum wheat reference genomes. The markers with known locations were distributed across all chromosomes with relatively well-balanced genome-wide coverage. The genetic analysis showed that the Spanish wheat landraces were clustered in different groups, thus representing genetic pools providing a range of allelic variation. The subspecies had a major impact on the population structure of the durum wheat landraces, with three distinct clusters that corresponded to subsp. durum, turgidum and dicoccon being identified. The population structure of bread wheat landraces was mainly biased by geographic origin.ConclusionsThe results showed broader genetic diversity in the landraces compared to a reference set that included commercial varieties, and higher divergence between the landraces and the reference set in durum wheat than in bread wheat. The analyses revealed genomic regions whose patterns of variation were markedly different in the landraces and reference varieties, indicating loci that have been under selection during crop improvement, which could help to target breeding efforts. The results obtained from this work will provide a basis for future genome-wide association studies.