| 1. |
- Hagenblad, Jenny, et al.
(författare)
-
Exploring the population genetics of genebank and historical landrace varierties
- 2012
-
Ingår i: Genetic Resources and Crop Evolution. - : Springer. - 0925-9864 .- 1573-5109. ; 59:6, s. 1185-1199
-
Tidskriftsartikel (refereegranskat)abstract
- Landrace accessions have long been recognized as an important source of genetic diversity for crop species, and landraces are stored in genebanks across the world as genetic resources for future crop development. Landraces are also an important part of the human cultural heritage and as such they have been used for genetic studies to make inferences about historical agriculture. However, surprisingly little is known about the within-accession diversity of landrace crops of different species. In order to evaluate the diversity of Swedish landraces we used microsatellite markers to genotype accessions of four species (barley, pea, oats and rye), both extant genebank material and 114-year-old seed samples of similar geographic origin and type. We found consistently high levels of within-population genetic diversity in the historical material, but varying and often lower diversity levels in the genebank accessions. We also make tentative conclusions about how representative the genebank material is to what was originally cultivated in its reported area of origin and suggest that the true identity of the genebank accessions is unclear and that historical seed collections should be a more appropriate material for the study of historical agriculture.
|
|
| 2. |
- Aslan, Selcuk, et al.
(författare)
-
Molecular Genotyping of HistoricalBarley Landraces Reveals Novel CandidateRegions for Local Adaption
- 2015
-
Ingår i: Crop science. - : Crop Science Society of America. - 0011-183X .- 1435-0653. ; 55:6, s. 2766-2776
-
Tidskriftsartikel (refereegranskat)abstract
- Barley landraces from Northern Europe formgenetically distinct latitudinal groups, suggestingthat adaption plays an important role inthe geographical distribution of genetic diversity.Here, we investigate how Northern Europeanbarley landraces relate to landraces fromother parts of Europe and whether candidategenes for climate adaption can be identified.For this purpose, 27 barley landraces, availableas century-old seed specimens, were genotypedwith a 384 single nucleotide polymorphism(SNP) assay. Landraces from the Nordiccountries formed a genetically distinct grouprelative to landraces from Central and SouthernEurope. Polymorphic positions in the floweringtime genes HvCO1, HvFT1, Ppd-H1, and VRN1-H1 were genotyped. The previously known alleledistribution of Ppd-H1 with the responsive allelepresent in the South and the nonresponsiveallele in the North was confirmed. The otherthree genes were more variable in Central andSouthern Europe compared to the North andneither of the flowering time genes showedany geographically correlated variation withinthe Nordic countries. Allelic frequencies fromthe 384 SNP set were correlated with climaticvariables. This allowed us to identify five SNPsputatively associated with length of growth season,and two SNPs putatively associated withprecipitation. The results show how historicalcrop specimens can be used to study howgenetic variation has been geographically distributedand the genetics of adaption.
|
|
| 3. |
- Asplund, Linnea, et al.
(författare)
-
Allelic Variation at the Rht8 Locus in a 19th Century Wheat Collection
- 2012
-
Ingår i: Scientific World Journal. - : Hindawi Limited. - 1537-744X .- 2356-6140. ; , s. 385610-
-
Tidskriftsartikel (refereegranskat)abstract
- Wheat breeding during the 20th century has put large efforts into reducing straw length and increasing harvest index. In the 1920s an allele of Rht8 with dwarfing effects, found in the Japanese cultivar “Akakomugi,” was bred into European cultivars and subsequently spread over the world. Rht8 has not been cloned, but the microsatellite marker WMS261 has been shown to be closely linked to it and is commonly used for genotyping Rht8. The “Akakomugi” allele is strongly associated with WMS261-192bp. Numerous screens of wheat cultivars with different geographical origin have been performed to study the spread and influence of the WMS261-192bp during 20th century plant breeding. However, the allelic diversity of WMS261 in wheat cultivars before modern plant breeding and introduction of the Japanese dwarfing genes is largely unknown. Here, we report a study of WMS261 allelic diversity in a historical wheat collection from 1865 representing worldwide major wheats at the time. The majority carried the previously reported 164 bp or 174 bp allele, but with little geographical correlation. In a few lines, a rare 182 bp fragment was found. Although straw length was recognized as an important character already in the 19th century, Rht8 probably played a minor role for height variation. The use of WMS261 and other functional markers for analyses of historical specimens and characterization of historic crop traits is discussed.
|
|
| 4. |
- Asplund, Linnea, et al.
(författare)
-
Re-evaluating the history of the wheat domestication gene NAM-B1 using historical plant material
- 2010
-
Ingår i: JOURNAL OF ARCHAEOLOGICAL SCIENCE. - : Elsevier Science B.V., Amsterdam. - 0305-4403 .- 1095-9238. ; 37:9, s. 2303-2307
-
Tidskriftsartikel (refereegranskat)abstract
- The development of agriculture is closely associated with the domestication of wheat, one of the earliest crop species. During domestication key genes underlying traits important to Neolithic agriculture were targeted by selection. One gene believed to be such a domestication gene is NAM-B1, affecting both nutritional quality and yield but with opposite effects. A null mutation, first arisen in emmer wheat, decreases the nutritional quality but delays maturity and increases grain size; previously the ancestral allele was believed lost during the domestication of durum and bread wheat by indirect selection for larger grain. By genotyping 63 historical seed samples originating from the 1862 International Exhibition in London, we found that the ancestral allele was present in two spelt wheat and two bread wheat cultivars widely cultivated at the time. This suggests that fixation of the mutated allele of NAM-B1 in bread wheat, if at all, occurred during modern crop improvement rather than during domestication. We also discuss the value of using archaeological and historical plant material to further the understanding of the development of agriculture.
|
|
| 5. |
- Charlesworth, Deborah, et al.
(författare)
-
Trans-specificity at Loci Near the Self-Incompatibility Loci in Arabidopsis
- 2006
-
Ingår i: Genetics. - : Oxford University Press (OUP). - 0016-6731 .- 1943-2631. ; 172:4, s. 2699-2704
-
Tidskriftsartikel (refereegranskat)abstract
- We compared allele sequences of two loci near the Arabidopsis lyrata self-incompatibility (S) loci with sequences of A. thaliana orthologs and found high numbers of shared polymorphisms, even excluding singletons and sites likely to be highly mutable. This suggests maintenance of entire S-haplotypes for long evolutionary times and extreme recombination suppression in the region.
|
|
| 6. |
- De Frenne, Pieter, et al.
(författare)
-
Biological Flora of the British Isles : Milium effusum
- 2017
-
Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 105:3, s. 839-858
-
Tidskriftsartikel (refereegranskat)abstract
- 1. This account presents information on all aspects of the biology of Milium effusum L. (Wood Millet) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation.2. The grass Milium effusum is a common species of mature woodland in central and southern England, but is less common in the wetter parts of northern England, Wales, Scotland and Ireland. Worldwide, the species is native to many temperate, boreal, subarctic and subalpine parts of the northern hemisphere: from eastern North America across most of Europe (excluding Mediterranean climates) to the Ural Mountains and Black Sea, extending eastwards to the Himalaya, Korea and Japan.3. Wood Millet is a shade-tolerant, relatively tall grass (up to 1.8 m) producing up to 700 caryopses per individual. It is characteristic of temperate deciduous woodland, but can also occur in other woodland and forest types and even in scrub, alpine meadows, along railways and roads, and on rocks. In woods, it is one of the most conspicuous plants of the herb layer in the early summer after the disappearance of spring flowering species. While the species is generally considered an ancient woodland indicator in England and western Europe, it is also known to colonize secondary, post-agricultural forests relatively rapidly in other areas such as Denmark, southern Sweden and Poland.4. The species has a wide amplitude in terms of soil acidity and nutrient availability, but predominantly grows on soils of intermediate soil fertility and soil pH and with high organic matter concentration. However, M. effusum can tolerate large quantities of tree-leaf litter on the forest floor and is able to grow on very acidic soils.5. Changes in land use, climate, densities of large herbivores and atmospheric deposition of nitrogen are having effects on populations of Wood Millet. Significant responses of the life-history traits and population characteristics have been detected in response to environmental variation and to experimental treatments of temperature, nutrients, light and acidity. In many of its habitats across its range, M. effusum is currently becoming more frequent. During the last century, its mean elevation of occurrence in upland areas of Europe has also increased by several hundreds of metres. Typically, management actions are directed towards the conservation of its main habitat type (e.g. ancient woodlands of the Milio-Fagetum association) rather than to the species specifically.
|
|
| 7. |
- Edstam, Monika, 1981-
(författare)
-
Plant lipid transfer proteins : Evolution, expression and function
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The plant non-specific lipid transfer proteins (nsLTPs) are known for the ability to transfer different lipids in vitro, but their in vivo functions have not yet been elucidated. They seem to play a role in the defense against biotic and abiotic stresses; the gene expression of nsLTPs is often upregulated when exposed to stresses. Further, two different nsLTPs have been shown to affect the lipid composition of the plant cuticle, a structure acting as a protective barrier. However, more evidence is needed to prove this hypothesis and to pinpoint their exact role in this process.In this thesis I have shown that the nsLTPs are found in all land plants, but not in any of the studied algae. This supports a role in defense response, since protection against dehydration, radiation, pathogens and other stresses played a crucial role when plants adapted to a life on land. Characterization of the nsLTPs in early diverging land plant revealed that even though the amino acid similarity towards nsLTPs in flowering plants is not very high, the main properties of the proteins are still the same (Paper I). This includes the protein structure, which consists of α-helices surrounding a lipid binding cavity, a conserved pattern of cysteine residues involved in disulphide bonds and a signal sequence directing the protein to the extracellular space. Further, the expression of nsLTPs in the moss Physcomitrella patens was shown to respond to stresses, and construction of an YFP-LTP fusion protein confirmed the localization to the periphery of the cell in planta (Paper II). Heterologous expressed Physcomitrella nsLTPs were also shown to have the ability to bind lipids and to be very heat stable, features previously only studied in nsLTPs from flowering plants. By examining the presence of a cuticle in Physcomitrella, a correlation between the nsLTPs´ lipid binding ability and the lipid composition of the cuticle could be found, which further strengthens the involvement of nsLTPs in transfer of lipids for cuticle construction.In the flowering plant Arabidopsis thaliana, I showed that several of the nsLTPs followed the same expression pattern when examining data from different tissues, stress treatments, hormones, chemical treatments and developmental stages, but also that four of the genes were undergoing alternative splicing resulting in different isoforms of the proteins (Paper III). Based on their expression patterns, the genes could be divided into three different coexpression networks. By examining other genes similarly expressed, each network could be designated to a putative function: Transfer of lipids for synthesis of the cuticle, suberin layer and sporopollenin, respectively. In Paper IV, these hypotheses were tested in vivo by examining knockout mutants of several nsLTPs in Arabidopsis. The involvement in sporopollenin deposition could be confirmed; two of the knockout lines showed collapsed pollen grains. Further, two other lines showed an increased seed coat permeability due to an altered lipid composition of the suberin layer. Together, the results support a role for nsLTPs in construction of the protecting barriers in all land plants.
|
|
| 8. |
- Forsberg, Nils, et al.
(författare)
-
Farmers without borders-genetic structuring in century old barley (Hordeum vulgare)
- 2015
-
Ingår i: Heredity. - : Nature Publishing Group. - 0018-067X .- 1365-2540. ; 114:2, s. 195-206
-
Tidskriftsartikel (refereegranskat)abstract
- The geographic distribution of genetic diversity can reveal the evolutionary history of a species. For crop plants, phylogeographic patterns also indicate how seed has been exchanged and spread in agrarian communities. Such patterns are, however, easily blurred by the intense seed trade, plant improvement and even genebank conservation during the twentieth century, and discerning fine-scale phylogeographic patterns is thus particularly challenging. Using historical crop specimens, these problems are circumvented and we show here how high-throughput genotyping of historical nineteenth century crop specimens can reveal detailed geographic population structure. Thirty-one historical and nine extant accessions of North European landrace barley (Hordeum vulgare L.), in total 231 individuals, were genotyped on a 384 single nucleotide polymorphism assay. The historical material shows constant high levels of within-accession diversity, whereas the extant accessions show more varying levels of diversity and a higher degree of total genotype sharing. Structure, discriminant analysis of principal components and principal component analysis cluster the accessions in latitudinal groups across country borders in Finland, Norway and Sweden. FST statistics indicate strong differentiation between accessions from southern Fennoscandia and accessions from central or northern Fennoscandia, and less differentiation between central and northern accessions. These findings are discussed in the context of contrasting historical records on intense within-country south to north seed movement. Our results suggest that although seeds were traded long distances, long-term cultivation has instead been of locally available, possibly better adapted, genotypes.
|
|
| 9. |
- Forsberg, Nils, 1981-, et al.
(författare)
-
Population structure in landrace barley (Hordeum vulgare L.) during the late 19th century crop failures in Fennoscandia
- 2019
-
Ingår i: Heredity. - : Springer Science and Business Media LLC. - 0018-067X .- 1365-2540. ; 123:6, s. 733-745
-
Tidskriftsartikel (refereegranskat)abstract
- Agricultural disasters and the subsequent need for supply of relief seed can be expected to influence the genetic composition of crop plant populations. The consequences of disasters and seed relief have, however, rarely been studied since specimens sampled before the events are seldomly available. A series of crop failures struck northern Fennoscandia (Norway, Sweden and Finland) during the second half of the 19th century. In order to assess population genetic dynamics of landrace barley (Hordeum vulgare), and consequences of crop failure and possible seed relief during this time period, we genotyped seeds from 16 historical accessions originating from two time periods spanning the period of repeated crop failure. Reliable identification of genetic structuring is highly dependent on sampling regimes and detecting fine-scale geographic or temporal differentiation requires large sample sizes. The robustness of the results under different sampling regimes was evaluated by analyzing subsets of the data and an artificially pooled dataset. The results led to the conclusion that six individuals per accession were insufficient for reliable detection of the observed genetic structure. We found that population structure among the data was best explained by collection year of accessions, rather than geographic origin. The correlation with collection year indicated a change in genetic composition of landrace barley in the area after repeated crop failures, likely a consequence of introgression of relief seed in local populations. Identical genotypes were found to be shared among some accessions, suggesting founder effects and local seed exchange along known routes for trade and cultural exchange.
|
|
| 10. |
- Hagenblad, Jenny, et al.
(författare)
-
An Evolutionary Approach to the History of Barley (Hordeum vulgare) Cultivation in the Canary Islands
- 2020
-
Ingår i: African Archaeological Review. - : SPRINGER. - 0263-0338 .- 1572-9842. ; 37, s. 579-595
-
Tidskriftsartikel (refereegranskat)abstract
- The Canary Islands are an archipelago that lies about 100 km west of North Africa. Barley (Hordeum vulgare) has been continuously cultivated since the colonization of the islands. To investigate the agricultural history of the islands, the DNA from multiple individuals of six extant landraces of barley was sequenced, and the resulting data were analyzed with ABC modeling. Estimates of separation times of barley populations on the different islands and the mainland were congruent with archaeological dating of the earliest settlements on the islands. The results of the genetic analyses were consistent with the continuous cultivation of barley on Lanzarote island since it was first colonized, but suggested cultivation was carried out at a smaller scale than on Gran Canaria and Tenerife. Contrary to archaeological evidence and early written historical sources, the genetic analyses suggest that barley was cultivated on a larger scale on Tenerife than on Gran Canaria. The genetic analysis of contemporary barley added support to the dating of the colonization of the islands and pointed to the need for more archaeological data concerning barley cultivation on Tenerife.
|
|
