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- Hagenblad, Jenny, Associate Professor, 1974-, et al.
(författare)
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Data from: Farmers without borders - genetic structuring in century old barley (Hordeum vulgare)
- 2014
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Annan publikationabstract
- 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.
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| 2. |
- Hagenblad, Jenny, et al.
(författare)
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Geographical distribution of genetic diversity in Secale landrace and wild accessions
- 2016
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Ingår i: BMC Plant Biology. - : BioMed Central. - 1471-2229. ; 16:23
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Tidskriftsartikel (refereegranskat)abstract
- Background: Rye, Secale cereale L., has historically been a crop of major importance and is still a key cereal in manyparts of Europe. Single populations of cultivated rye have been shown to capture a large proportion of the geneticdiversity present in the species, but the distribution of genetic diversity in subspecies and across geographical areasis largely unknown. Here we explore the structure of genetic diversity in landrace rye and relate it to that of wildand feral relatives.Results: A total of 567 SNPs were analysed in 434 individuals from 76 accessions of wild, feral and cultivated rye. Geneticdiversity was highest in cultivated rye, slightly lower in feral rye taxa and significantly lower in the wild S. strictum Presl.and S. africanum Stapf. Evaluation of effects from ascertainment bias suggests underestimation of diversity primarily inS. strictum and S. africanum. Levels of ascertainment bias, STRUCTURE and principal component analyses all supportedthe proposed classification of S. africanum and S. strictum as a separate species from S. cereale. S. afghanicum (Vav.)Roshev, S. ancestrale Zhuk., S. dighoricum(Vav.) Roshev, S. segetale (Zhuk.) Roshev and S. vavilovii Grossh. seemed, incontrast, to share the same gene pool as S. cereale and their genetic clustering was more dependent on geographicalorigin than taxonomic classification. S. vavilovii was found to be the most likely wild ancestor of cultivated rye. Amongcultivated rye landraces from Europe, Asia and North Africa five geographically discrete genetic clusters were identified.These had only limited overlap with major agro-climatic zones. Slash-and-burn rye from the Finnmark area in Scandinaviaformed a distinct cluster with little similarity to other landrace ryes. Regional studies of Northern and South-West Europedemonstrate different genetic distribution patterns as a result of varying cultivation intensity.Conclusions: With the exception of S. strictum and S. africanum different rye taxa share the majority of the geneticvariation. Due to the vast sharing of genetic diversity within the S. cereale clade, ascertainment bias seems to be a lesserproblem in rye than in predominantly selfing species. By exploiting within accession diversity geographic structure can beshown on a much finer scale than previously reported.
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