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Molecular evaluation of orphan Afghan common wheat (Triticum aestivum L.) landraces collected by Dr. Kihara using single nucleotide polymorphic markers.

Manickavelu A, Jighly A, Ban T - BMC Plant Biol. (2014)

Bottom Line: Here we used SNP analysis to demonstrate the importance of Afghan wheat landraces and found tremendous genetic diversity and province-specific characteristics unique to this geographic region.This result closely resembles existing agro-climatic zones within Afghanistan, as well as the wheat varieties commonly cultivated within these regions.Molecular variance analysis showed a higher proportion of intra-province variation among landraces compared with variation among all landraces as a whole.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Landraces are an important source of genetic diversity in common wheat, but archival collections of Afghan wheat landraces remain poorly characterised. The recent development of array based marker systems, particularly single nucleotide polymorphism (SNP) markers, provide an excellent tool for examining the genetic diversity of local populations. Here we used SNP analysis to demonstrate the importance of Afghan wheat landraces and found tremendous genetic diversity and province-specific characteristics unique to this geographic region.

Results: A total of 446 Afghan wheat landraces were analysed using genotype by sequencing (GBS) arrays containing ~10 K unique markers. Pair-wise genetic distance analyses revealed significant genetic distances between landraces, particularly among those collected from distanced provinces. From these analyses, we were able to divide the landraces into 14 major classes, with the greatest degree of diversity evident among landraces isolated from Badakhshan province. Population-based analyses revealed an additional 15 sub-populations within our germplasm, and significant correlations were evident in both the provincial and botanical varieties. Genetic distance analysis was used to identify differences among provinces, with the strongest correlations seen between landraces from Herat and Ghor province, followed closely by those between Badakhshan and Takhar provinces. This result closely resembles existing agro-climatic zones within Afghanistan, as well as the wheat varieties commonly cultivated within these regions. Molecular variance analysis showed a higher proportion of intra-province variation among landraces compared with variation among all landraces as a whole.

Conclusion: The SNP analyses presented here highlight the importance and genetic diversity of Afghan wheat landraces. Furthermore, these data strongly refute a previous analysis that suggested low genetic diverse within this germplasm. Ongoing analyses include phenotypic characterisation of these landraces to identify functional traits associated with individual genotypes. Taken together, these analyses can be used to help improve wheat cultivation in Afghanistan, while providing insights into the evolution and selective pressures underlying these distinct landraces.

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Geographical location of Afghan wheat landraces and their grouping based on agro-ecological zones. The map is divide into eight agro-ecological zones according to FAO [Food and Agricultural Organization]. The number of accessions from each province are shown in green squared boxes.
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Related In: Results  -  Collection

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Fig1: Geographical location of Afghan wheat landraces and their grouping based on agro-ecological zones. The map is divide into eight agro-ecological zones according to FAO [Food and Agricultural Organization]. The number of accessions from each province are shown in green squared boxes.

Mentions: Although the importance of landraces in terms of both conservation and utilisation remain controversial [2], much of this uncertainty stems from the lack of reliable data regarding the use and implementation of these resources [16-18]. Over the past few decades, significant efforts have been invested in the collection, preservation, and use of landraces worldwide. However, these efforts have failed to address the role of Afghan wheat landraces, a significant absence given the historical significance of this region in the domestication of wheat. While little remains of the local Afghan stocks, private collections, such as the one initiated by Dr. Kihara, have preserved much of the original diversity, accounting for ~500 unique Afghan landraces [19]. Furthermore, the Kihara collection was maintained and preserved in both pure and homozygous states, increasing the novelty of these materials relative to other landraces. In addition, this germplasm contains representative landraces from all of the wheat-growing areas of Afghanistan, across eight agro-climatic zones, allowing for the most comprehensive study of the Afghan wheat gene pool to date (FigureĀ 1) [1]. Recently Mitrofanova et al. [16] examined the genetic diversity of Afghan bread wheat landraces by compiling data available through all of the major gene banks worldwide. However, the scope of this analysis included only a small subset of available lines, with characterizations limited to just a handful of SSR markers.Figure 1


Molecular evaluation of orphan Afghan common wheat (Triticum aestivum L.) landraces collected by Dr. Kihara using single nucleotide polymorphic markers.

Manickavelu A, Jighly A, Ban T - BMC Plant Biol. (2014)

Geographical location of Afghan wheat landraces and their grouping based on agro-ecological zones. The map is divide into eight agro-ecological zones according to FAO [Food and Agricultural Organization]. The number of accessions from each province are shown in green squared boxes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4255927&req=5

Fig1: Geographical location of Afghan wheat landraces and their grouping based on agro-ecological zones. The map is divide into eight agro-ecological zones according to FAO [Food and Agricultural Organization]. The number of accessions from each province are shown in green squared boxes.
Mentions: Although the importance of landraces in terms of both conservation and utilisation remain controversial [2], much of this uncertainty stems from the lack of reliable data regarding the use and implementation of these resources [16-18]. Over the past few decades, significant efforts have been invested in the collection, preservation, and use of landraces worldwide. However, these efforts have failed to address the role of Afghan wheat landraces, a significant absence given the historical significance of this region in the domestication of wheat. While little remains of the local Afghan stocks, private collections, such as the one initiated by Dr. Kihara, have preserved much of the original diversity, accounting for ~500 unique Afghan landraces [19]. Furthermore, the Kihara collection was maintained and preserved in both pure and homozygous states, increasing the novelty of these materials relative to other landraces. In addition, this germplasm contains representative landraces from all of the wheat-growing areas of Afghanistan, across eight agro-climatic zones, allowing for the most comprehensive study of the Afghan wheat gene pool to date (FigureĀ 1) [1]. Recently Mitrofanova et al. [16] examined the genetic diversity of Afghan bread wheat landraces by compiling data available through all of the major gene banks worldwide. However, the scope of this analysis included only a small subset of available lines, with characterizations limited to just a handful of SSR markers.Figure 1

Bottom Line: Here we used SNP analysis to demonstrate the importance of Afghan wheat landraces and found tremendous genetic diversity and province-specific characteristics unique to this geographic region.This result closely resembles existing agro-climatic zones within Afghanistan, as well as the wheat varieties commonly cultivated within these regions.Molecular variance analysis showed a higher proportion of intra-province variation among landraces compared with variation among all landraces as a whole.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Landraces are an important source of genetic diversity in common wheat, but archival collections of Afghan wheat landraces remain poorly characterised. The recent development of array based marker systems, particularly single nucleotide polymorphism (SNP) markers, provide an excellent tool for examining the genetic diversity of local populations. Here we used SNP analysis to demonstrate the importance of Afghan wheat landraces and found tremendous genetic diversity and province-specific characteristics unique to this geographic region.

Results: A total of 446 Afghan wheat landraces were analysed using genotype by sequencing (GBS) arrays containing ~10 K unique markers. Pair-wise genetic distance analyses revealed significant genetic distances between landraces, particularly among those collected from distanced provinces. From these analyses, we were able to divide the landraces into 14 major classes, with the greatest degree of diversity evident among landraces isolated from Badakhshan province. Population-based analyses revealed an additional 15 sub-populations within our germplasm, and significant correlations were evident in both the provincial and botanical varieties. Genetic distance analysis was used to identify differences among provinces, with the strongest correlations seen between landraces from Herat and Ghor province, followed closely by those between Badakhshan and Takhar provinces. This result closely resembles existing agro-climatic zones within Afghanistan, as well as the wheat varieties commonly cultivated within these regions. Molecular variance analysis showed a higher proportion of intra-province variation among landraces compared with variation among all landraces as a whole.

Conclusion: The SNP analyses presented here highlight the importance and genetic diversity of Afghan wheat landraces. Furthermore, these data strongly refute a previous analysis that suggested low genetic diverse within this germplasm. Ongoing analyses include phenotypic characterisation of these landraces to identify functional traits associated with individual genotypes. Taken together, these analyses can be used to help improve wheat cultivation in Afghanistan, while providing insights into the evolution and selective pressures underlying these distinct landraces.

Show MeSH