scholarly journals Genetic diversity of Ethiopian durum wheat landraces

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247016
Author(s):  
Kefyalew Negisho ◽  
Surafel Shibru ◽  
Klaus Pillen ◽  
Frank Ordon ◽  
Gwendolin Wehner

Genetic diversity and population structure assessment in crops is essential for marker trait association, marker assisted breeding and crop germplasm conservation. We analyzed a set of 285 durum wheat accessions comprising 215 Ethiopian durum wheat landraces, 10 released durum wheat varieties, 10 advanced durum wheat lines from Ethiopia, and 50 durum wheat lines from CIMMYT. We investigated the genetic diversity and population structure for the complete panel as well as for the 215 landraces, separately based on 11,919 SNP markers with known physical positions. The whole panel was clustered into two populations representing on the one hand mainly the landraces, and on the other hand mainly released, advanced and CIMMYT lines. Further population structure analysis of the landraces uncovered 4 subgroups emphasizing the high degree of genetic diversity within Ethiopian durum landraces. Population structure based AMOVA for both sets unveiled significant (P < 0.001) variation between populations and within populations. Total variation within population accessions (81%, 76%) was higher than total variation between populations (19%, 24%) for both sets. Population structure analysis based genetic differentiation (FST) and gene flow (Nm) for the whole set and the Ethiopian landraces were 0.19 and 0.24, 1.04, and 0.81, respectively indicating high genetic differentiation and limited gene flow. Diversity indices verify that the landrace panel was more diverse with (I = 0.7, He = 0.46, uHe = 0.46) than the advanced lines (I = 0.6, He = 0.42, uHe = 0.42). Similarly, differences within the landrace clusters were observed. In summary a high genetic diversity within Ethiopian durum wheat landraces was detected, which may be a target for national and international wheat improvement programs to exploit valuable traits for biotic and abiotic stresses.

2021 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Bahri ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
Udupa M. Sri ◽  
...  

Abstract Background: Septoria tritici blotch (STB) has marked durum wheat production worldwide. This fungal disease is until today a challenge for farmers, researchers and breeders all united in the aim of reducing its damage and improving wheat resistance. Tunisian durum wheat landraces were reported to be valuable genetic resources for resistance to biotic and abiotic stresses and are therefore prominently deployed in breeding programs to develop new varieties adapted to fungal diseases as STB and to climate change constraints overall.Results: A total of 366 local durum wheat accessions were assessed for resistance to two virulent Tunisian isolates of Zymoseptoria tritici Tun06 and TM220 under field conditions. Population structure analysis of the durum wheat accessions, performed with 286 polymorphic SNPs (PIC >0.3) covering the entire genome, identified three genetic subpopulations (GS1, GS2 and GS3) with 22% of admixed genotypes. Interestingly, all of the resistant genotypes were among GS2 or admixed with GS2. Conclusions: This study revealed the population structure and the genetic distribution of the resistance to Z. tritici in the Tunisian durum wheat landraces. The grouping pattern of accessions appear to be associated, to some extent, with the geographical pattern of the landraces. We suggested that GS2 accessions were mostly introduced from eastern Mediterranean populations, unlike GS1 and GS3 that originated from the west. Resistant GS2 accessions belonged to landraces Taganrog, Sbei glabre, Richi, Mekki, Badri, Jneh Khotifa and Azizi. Furthermore, we suggested that admixture contributed to transmit STB resistance from GS2 resistant landraces to initially susceptible landraces such as Mahmoudi (GS1), but also resulted in the loss of resistance in the case of GS2 suscpetible Azizi and Jneh Khotifa accessions.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Oumer Abdie Oumer ◽  
Kassahun Tesfaye ◽  
Tileye Feyissa ◽  
Dagnew Yibeyen ◽  
Jayaraman Durai ◽  
...  

Background. As a member of Poaceae and subfamily Bambusoideae, Ethiopian lowland bamboo (Oxytenanthera abyssinica) is one of the most important nontimber forest resources or a potential alternative to wood and wood products. Ethiopia contributes 86% of the total area of bamboo on the continent, Africa, and 7% of the world. O. abyssinica in Ethiopia accounts for 85% of the total national coverage of bamboo. Several studies have been performed on the genetic diversity and population structure analysis of various bamboo species throughout the world but almost nothing in Ethiopia and O. abyssinica. Methods. Young fresh leaves of O. abyssinica from thirteen natural lowland bamboo growing areas across the country were collected. DNA was isolated using a modified CTAB DNA isolation method. Three cpDNA gene sequences (matK, ndhF3, and rps16) were used for the study. PCR products were analyzed, purified, and pair-end sequenced to calculate AC/GC content, average number of nucleotide differences (k), nucleotide diversity (π) and population mutation rates per 100 sites ( θ w ), InDel (Insertion-Deletion), DNA divergence, gene flow, and genetic differentiation. Results. Metekel Zone was found to have extremely higher k, π, and θ w . Higher frequency of genetic differentiation was found between Metekel Zone vs. the distant populations. Higher frequency of gene flow was found between Assosa Zone vs. Oromia populations. Kurmuk haplotype from gaps or missing data considered and Bambasi haplotype from not considered has descendants around them. Conclusion. Using sequences of cpDNA genes, populations of O. abyssinica collected in Ethiopia show clear diversity based on their geographic location. Metekel Zone was found to have the most diverse population, Assosa Zone has been found to be the source of evolution of O. abyssinica, and Gambella population shows a difference from other O. abyssinica populations.


2021 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Bahri ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
Udupa . Sripa ◽  
...  

Abstract Background: Septoria tritici blotch (STB) has marked durum wheat production worldwide. This fungal disease is until today a challenge for farmers, researchers and breeders all united in the aim of reducing its damage and improving wheat resistance. Tunisian durum wheat landraces were reported to be valuable genetic resources for resistance to biotic and abiotic stresses and are therefore prominently deployed in breeding programs to develop new varieties adapted to fungal diseases as STB and to climate change constraints overall.Results: A total of 366 local durum wheat accessions were assessed for resistance to two virulent Tunisian isolates of Zymoseptoria tritici Tun06 and TM220 under field conditions. Population structure analysis of the durum wheat accessions, performed with 286 polymorphic SNPs (PIC >0.3) covering the entire genome, identified three genetic subpopulations (GS1, GS2 and GS3) with 22% of admixed genotypes. Interestingly, all of the resistant genotypes were among GS2 or admixed with GS2. Conclusions: This study revealed the population structure and the genetic distribution of the resistance to Z. tritici in the Tunisian durum wheat landraces. The grouping pattern of accessions appear to be associated, to some extent, with the geographical pattern of the landraces. We suggested that GS2 accessions were mostly introduced from eastern Mediterranean populations, unlike GS1 and GS3 that originated from the west. Resistant GS2 accessions belonged to landraces Taganrog, Sbei glabre, Richi, Mekki, Badri, Jneh Khotifa and Azizi. Furthermore, we suggested that admixture contributed to transmit STB resistance from GS2 resistant landraces to initially susceptible landraces such as Mahmoudi (GS1), but also resulted in the loss of resistance in the case of GS2 suscpetible Azizi and Jneh Khotifa accessions.


Plants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 116 ◽  
Author(s):  
Fiore ◽  
Mercati ◽  
Spina ◽  
Blangiforti ◽  
Venora ◽  
...  

During the XX Century, the widespread use of modern wheat cultivars drastically reduced the cultivation of ancient landraces, which nowadays are confined to niche cultivation areas. Several durum wheat landraces adapted to the extreme environments of the Mediterranean region, are still being cultivated in Sicily, Italy. Detailed knowledge of the genetic diversity of this germplasm could lay the basis for their efficient management in breeding programs, for a wide-range range of traits. The aim of the present study was to characterize a collection of durum wheat landraces from Sicily, using single nucleotide polymorphisms (SNP) markers, together with agro-morphological, phenological and quality-related traits. Two modern cv. Simeto, Claudio, and the hexaploid landrace, Cuccitta, were used as outgroups. Cluster analysis and Principal Coordinates Analysis (PCoA) allowed us to identify four main clusters across the analyzed germplasm, among which a cluster included only historical and modern varieties. Likewise, structure analysis was able to distinguish the ancient varieties from the others, grouping the entries in seven cryptic genetic clusters. Furthermore, a Principal Component Analysis (PCA) was able to separate the modern testers from the ancient germplasm. This approach was useful to classify and evaluate Sicilian ancient wheat germplasm, supporting their safeguard and providing a genetic fingerprint that is necessary for avoiding commercial frauds to sustaining the economic profits of farmers resorting to landraces cultivation.


2019 ◽  
Author(s):  
Laura Pascual ◽  
Magdalena Ruiz ◽  
Matilde López-Fernández ◽  
Helena Pérez-Peña ◽  
Elena Benavente ◽  
...  

Abstract Background One of the main goals for the XXI century breeding is the development of crop cultivars that can maintain current yields under unfavorable environments. Landraces that have been grown under varied 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 (CRF-INIA) holds a wide collection of wheat landraces. These accessions, locally adapted to a really wide diversity of eco-climatic conditions, represent a highly valuable material 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. Results DArTseq GBS approach generated 10K SNPs and 40K DArT high-quality markers that were mapped against the currently available bread wheat reference genome. The markers with known location were distributed in all the chromosomes, having a relatively well-balanced genome-wide coverage. The genetic analysis showed that Spanish wheat landraces are clustered in different groups, thus representing genetic pools capable to provide different allelic variation. The subspecies had a major impact on the population structure of durum wheat landraces, identifying three different clusters that corresponded to subsps. durum, turgidum and dicoccon. The population structure of bread wheat landraces was more biased by geographic origin. Conclusions The results showed a wider genetic diversity in landraces when compared to a reference set that included commercial varieties, and a higher divergence between landraces and the reference set in durum wheat than in bread wheat. Some genomic regions with patterns of variation that differ between landraces and reference varieties could be detected, pointing out loci under selection during crop improvement that could help to target breeding efforts. The results obtained from this work will be highly valuable for future GWAS analysis.


Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 340
Author(s):  
Muhammad Massub Tehseen ◽  
Deniz Istipliler ◽  
Zakaria Kehel ◽  
Carolina P. Sansaloni ◽  
Marta da Silva Lopes ◽  
...  

Landraces are a potential source of genetic diversity and provide useful genetic resources to cope with the current and future challenges in crop breeding. Afghanistan is located close to the centre of origin of hexaploid wheat. Therefore, understanding the population structure and genetic diversity of Afghan wheat landraces is of enormous importance in breeding programmes for the development of high-yielding cultivars as well as broadening the genetic base of bread wheat. Here, a panel of 363 bread wheat landraces collected from seven north and north-eastern provinces of Afghanistan were evaluated for population structure and genetic diversity using single nucleotide polymorphic markers (SNPs). The genotyping-by-sequencing of studied landraces after quality control provided 4897 high-quality SNPs distributed across the genomes A (33.75%), B (38.73%), and D (27.50%). The population structure analysis was carried out by two methods using model-based STRUCTURE analysis and cluster-based discriminant analysis of principal components (DAPC). The analysis of molecular variance showed a higher proportion of variation within the sub-populations compared with the variation observed as a whole between sub-populations. STRUCTURE and DAPC analysis grouped the majority of the landraces from Badakhshan and Takhar together in one cluster and the landraces from Baghlan and Kunduz in a second cluster, which is in accordance with the micro-climatic conditions prevalent within the north-eastern agro-ecological zone. Genetic distance analysis was also studied to identify differences among the Afghan regions; the strongest correlation was observed for the Badakhshan and Takhar (0.003), whereas Samangan and Konarha (0.399) showed the highest genetic distance. The population structure and genetic diversity analysis highlighted the complex genetic variation present in the landraces which were highly correlated to the geographic origin and micro-climatic conditions within the agro-climatic zones of the landraces. The higher proportions of admixture could be attributed to historical unsupervised exchanges of seeds between the farmers of the central and north-eastern provinces of Afghanistan. The results of this study will provide useful information for genetic improvement in wheat and is essential for association mapping and genomic prediction studies to identify novel sources for resistance to abiotic and biotic stresses.


2020 ◽  
Author(s):  
Laura Pascual ◽  
Magdalena Ruiz ◽  
Matilde López-Fernández ◽  
Helena Pérez-Peña ◽  
Elena Benavente ◽  
...  

Abstract Background One of the main goals of the plant breeding in the 21 st 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. Results The DArTseq GBS approach generated 10K SNPs and 40K 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 subsps. durum , turgidum and dicoccon being identified. The population structure of bread wheat landraces was mainly biased by geographic origin. Conclusions The 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.


AGROFOR ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Kristína LEHOCKÁ ◽  
Radovan KASARDA ◽  
Barbora OLŠANSKÁ ◽  
Nina MORAVČÍKOVÁ

The aim of the study was to estimate genetic drift and gene flow related to population structure and genetic diversity in selected beef cattle. For the evaluation of the genetic drift and gene flow among analysed populations, the Bayesian Population Structure Analysis and software Treemix were used. The genetic analysis included two cattle breeds bred in Slovakia (Charolais and Limousine). In addition to the Limousine and Charolais breeds, other beef cattle (Angus N = 90, Belgian Blue N = 4, Blonde d'Aquitaine N= 5, Hereford N = 98 and Red Angus N = 15) were analysed. The 50k Bead chip was used; the dataset consisted of 34,834 SNPs. To avoid detection bias, SNPs with high linkage disequilibrium (r2 = 0.05) were pruned from the database; the final data set consisted of 296 animals and 2,539 SNP markers. Our results reflected four modes of gene flow between Angus, Red Angus, Charolais, Limousine and Hereford. Analysed breeds were not confirmed to influence genetic make-up of Belgian Blue and Blonde d'Aquitaine populations. All migration edges reached weight values below 0.2. The only two migration edges higher in weight was observed, first between the ancestor of Limousine breed into Blond d'Aquitaine, and second among historical ancestor of Hereford breed into Red Angus. Our results reflect that the donor population has made a significant contribution to the recipient population.


2019 ◽  
Author(s):  
Laura Pascual ◽  
Magdalena Ruiz ◽  
Matilde López-Fernández ◽  
Helena Pérez-Peña ◽  
Elena Benavente ◽  
...  

Abstract Background One of the main goals of the plant breeding in the 21 st 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. Results The DArTseq GBS approach generated 10K SNPs and 40K high-quality DArT markers, which were mapped 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 subsps. durum , turgidum and dicoccon being identified. The population structure of bread wheat landraces was mainly biased by geographic origin. Conclusions The 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.


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