Background: Emerging wheat stem rust races have become a major threat to global wheat production.... more Background: Emerging wheat stem rust races have become a major threat to global wheat production. Finding additional loci responsible for resistance to these races and incorporating them into currently cultivated varieties is the most economic and environmentally sound strategy to combat this problem. Thus, this study was aimed at characterizing the genetic diversity and identifying the genetic loci conferring resistance to the stem rust of wheat. To accomplish this, 245 elite lines introduced from the International Center for Agricultural Research in the Dry Areas (ICARDA) were evaluated under natural stem rust pressure in the field at the Debre Zeit Agricultural Research Center, Ethiopia. The single nucleotide polymorphisms (SNP) marker data was retrieved from a 15 K SNP wheat array. A mixed linear model was used to investigate the association between SNP markers and the best linear unbiased prediction (BLUP) values of the stem rust coefficient of infection (CI). Results: Phenotypic analysis revealed that 46% of the lines had a coefficient of infection (CI) in a range of 0 to 19. Genome-wide average values of 0.38, 0.20, and 0.71 were recorded for Nei's gene diversity, polymorphism information content, and major allele frequency, respectively. A total of 46 marker-trait associations (MTAs) encompassed within eleven quantitative trait loci (QTL) were detected on chromosomes 1B, 3A, 3B, 4A, 4B, and 5A for CI. Two major QTLs with-log 10 (p) ≥ 4 (EWYP1B.1 and EWYP1B.2) were discovered on chromosome 1B. Conclusions: This study identified several novel markers associated with stem rust resistance in wheat with the potential to facilitate durable rust resistance development through marker-assisted selection. It is recommended that the resistant wheat genotypes identified in this study be used in the national wheat breeding programs to improve stem rust resistance.
Ethiopian Journal of Applied Science and Technology, 2020
The study was conducted in the natural coffee forest ecosystems of southwest and southeast Ethiop... more The study was conducted in the natural coffee forest ecosystems of southwest and southeast Ethiopia, where the wild populations of Coffea arabica L. naturally grow. Soil is an important environmental factor that performs different important functions in the terrestrial ecosystems, including in the natural coffee forest ecosystems. The objective of this study was to investigate the link between soil properties and bean quality of wild Arabica coffee in the natural coffee forests of Ethiopia. Data on soil parameters and bean characteristics were assessed. Results from simple correlation analysis, stepwise regression analysis and ordination analysis (principal component analysis-PCA, redundancy analysis-RDA) showed that bean size distribution of wild Arabica coffee was clearly related to the soil characteristics of the natural coffee forest ecosystem. Monte Carlo permutation test for the first RDA axis was significant (p=0.0020) with 499 permutations. Forward selection procedure showed that soil pH, Mn, sand, Na, available P and organic matter (OM) significantly contributed to the variability in bean size distribution of wild Arabica coffee. Soil parameters such as soil pH, Mn, pH, CEC, OM, total N, Ca, Na and pH relatively favoured the development of larger beans, whereas higher available P, K and silt contributed to the development of smaller beans. Moreover, the first RDA axis clearly discriminated coffee samples of the southeast coffee forests from those of the southwest coffee forests, and the variation in bean characteristics clearly followed the trend of soil characteristics. Thus, soil is an important environmental factor for the physical quality of wild Arabica coffee.
The present study aimed to examine the PTC tasting ability in selected individuals from Ethiopia.... more The present study aimed to examine the PTC tasting ability in selected individuals from Ethiopia. It involved 465 participants representing four ethnic groups. A total of 69 individuals from Amhara (30 females and 39 males), 52 from Agnuak (3 females and 49 males), 59 from Nuer and 285 (60 females and 225 males) from Oromo were recruited. The investigation was made using a series of graded concentrations of PTC dissolved in pure water and the results were recorded. The participants were analyzed for the distribution of tasters and non-tasters for PTC. The frequency of dominant and recessive alleles of PTC gene was calculated using Hardy-Weinberg methods. The result showed that the frequency of tasters (82.80%) were significantly higher than that of non-tasters (17.20%) in all populations. Likewise, frequency of tasters among males (83.06%) and females (82.61%) were significantly higher than the frequency of non-taster males (16.94%) and females (17.39%). This shows that PTC tasting ...
Crop production is the main source of food, and drought is among the most important crop producti... more Crop production is the main source of food, and drought is among the most important crop production constraints in the world, particularly in sub-Saharan Africa. The use of improved cultivars can at least partly ameliorate the calamities of drought stress, and considerable investments and efforts have been made worldwide to develop drought tolerant crop cultivars. A number of improved cultivars of different crops have also been released for production in different countries. As related to the situation under normal environments, it is yet hardly possible to say that these investments and efforts have modernized the production under drought-prone environments as a whole and boosted the actual productivity as desired. Therefore, the limitations and strategic implications of past experiences made to develop drought tolerant crop cultivars needs to be synthesized in order to formulate better strategies and approaches. In this review article, the scope and impacts of drought, approaches ...
Coffee quality is a complex trait involving sensory and bean characteristics as well as biochemic... more Coffee quality is a complex trait involving sensory and bean characteristics as well as biochemical contents. The objective of this study was to assess the major factors influencing the quality of wild Arabica coffee (Coffea arabica L.) in the natural coffee forests of southwest and southeast Ethiopia. Results revealed that both natural (soil, aspect, elevation, climate, geographic location) and human factors (cherry harvesting/ handing, theft, forest management) considerably influenced the quality of wild Arabica coffee. The soil factor affected every component of coffee quality (cup quality, bean characteristics and biochemical contents). The cup quality of coffee varied with soil properties, especially with available P and soil texture. The bean size distribution was also affected by soil properties; there was significant positive relationship between soil pH, sand or Mn and the proportion of bold beans (retained on screen 17). Soil organic matter, total N and sand content were inversely correlated with caffeine content, but available P and clay content were positively correlated with caffeine. Increase in elevation led to increase in bean size up to the elevation of about 1600 m above sea level, but thereafter no more increase in bean size (hump-shaped relationship, not monotonic). Bean size increased with increase in longitude, but it decreased with increase in latitude. Cup quality was also significantly influenced by coffee harvesting and handling, but its influence was not noticed on bean size and biochemical contents. Coffee quality is therefore the resultant of an interaction of different natural and human factors prevailing in the respective area.
The human FMO2 (flavin-containing monooxygenase 2) gene has been shown to be involved in innate i... more The human FMO2 (flavin-containing monooxygenase 2) gene has been shown to be involved in innate immunity against microbial infections, including tuberculosis (TB), via the modulation of oxidative stress levels. It has also been found to possess a curious loss-offunction mutation (FMO2*1/FMO2*2) that demonstrates a distinctive differentiation in expression, function and ethno-geographic distribution. However, despite evidences of ethnic-specific genetic associations in the inflammatory profile of TB, no studies were done to investigate whether these patterns of variations correlate with evidences for the involvement of FMO2 in antimicrobial immune responses and ethnic differences in the distribution of FMO2 polymorphisms except for some pharmacogenetic data that suggest a potentially deleterious role for the functional variant (FMO2*1). This genetic epidemiological study was designed to investigate whether there is an association between FMO2 polymorphisms and TB, an ancient malady that remains a modern global health concern, in a sub-Saharan Africa setting where there is not only a relatively high co-prevalence of the disease and the ancestral FMO2*1 variant but also where both Mycobcaterium and Homo sapiens are considered to have originated and co-evolved. Blood samples and TB related clinical data were collected from ascertained TB cases and unrelated household controls (n = 292) from 3 different ethnic groups in Ethiopia. Latent Mtb infection was determined using Quantiferon to develop reliable TB progression phenotypes. We sequenced exonic regions of FMO2.We identified for the first time an association between FMO2 and TB both at the SNP and haplotype level. Two novel SNPs achieved a study-wide significance [chr1:171181877(A), p = 3.15E-07, OR = 4.644 and chr1:171165749(T), p = 3.32E-06, OR = 6.825] while multiple SNPs (22) showed nominal signals. The pattern of association suggested a protective effect of FMO2 against both active and latent TB with distinct genetic variants underlying the TB
The journal implements double-blind peer review practiced by specially invited international edit... more The journal implements double-blind peer review practiced by specially invited international editorial board members. [2] that bring about three phenotypic classes: Hp 1-1 , Hp 1-2 and Hp 2-2. Haptoglobin gene is principally expressed in the liver by hepatocytes[3], induced by cytokines such as interleukin-6 (IL-6), IL-1 and tumor necrosis factor-α (TNF-α)[4]. Structurally, it has four chains: 2α light chains and 2β heavy chains[5], and following its secretion, circulates as a linear dimer, or as a linear polymer, or as a cyclic polymer. In healthy human adults, plasma Hp level varies between 0.38 g/L and 2.08 g/L[6], but the range may elevate in response to inflammation, bacterial infection, tissue destruction and malignant diseases[4,7]. Besides its hemoglobin scavenging role, Hp has many biological functions such as oxidative stress prevention[8], anti-oxidant function[9], nitric oxide related function[10], antibacterial activities[6], renal damage prevention[6,8], antiinflammatory functions[8], inhibition of prostaglandin synthesis[11], and immune modulation[8,12]. The modulation function of Hp both
Abstract According to Food and Agriculture Organization (FAO), droughts have significant economic... more Abstract According to Food and Agriculture Organization (FAO), droughts have significant economic, environmental, and social impacts, both direct and indirect. All field crops are affected by drought. Global warming and climate change are expected to exacerbate this phenomenon. Barley (Hordeum vulgare L.) ranks fourth among cereals after wheat (Triticum aestivum L.), maize (Zea mays L.), and rice (Oryza sativa L.). Drought is a significant issue in barley breeding programs. The purpose of this chapter is to review pertinent literature on general drought-tolerance mechanisms in important field crops and provide the latest state-of-the-art information on drought-coping mechanisms in barley, including molecular basis of crop response in moisture-limited environments. We highlight research insights, existing gaps, and future research directions regarding drought tolerance in barley. Known quantitative trait loci (QTL) and genes, such as Dhn and DREB, and their use in marker-assisted selection for drought tolerance are summarized. Traits associated with improved performance (early vigor, plant height, spike waxiness, and thousand-grain weight) under low-moisture stress environments have been identified as useful criteria in breeding for drought-tolerant barley. Low stomatal density cultivars of barley should be developed to combat drought and climate change. Latest innovations in genome-editing technology, such as clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9), clustered regularly interspaced short palindromic repeats from Prevotella and Francisella 1 (CRISPR-Cpf1), and multiplexed accurate genome editing with short, trackable, integrated cellular barcodes (MAGESTIC), should be useful for plant breeders in modifying the barley genome, as needed, to develop drought-tolerant cultivars.
We studied the genetic pattern of 21 Ethiopian populations of Prunus africana by using six nuclea... more We studied the genetic pattern of 21 Ethiopian populations of Prunus africana by using six nuclear and five plastid microsatellites. In total, 89 alleles were found in the nuclear and 16 haplotypes in the plastid genome. High levels of diversity both in cpSSRs (hT = 0.703) and nSSR (HT = 0.725) were detected. Genetic differentiation among populations at the nuclear and plastid level was moderate (FST = 0.122 vs. GST = 0.478). While Ethiopian populations harbored the highest plastid haplotype diversity throughout Africa, the level of nuclear diversity was lower than in the remaining part of the species’ range. Ten of the observed 16 plastid haplotypes were unique to Ethiopia, suggesting an isolated plastid evolution. Remarkably, all plastid haplotypes found in Ethiopia belonged to one single lineage, while other populations from East Africa and Madagascar contain haplotypes from up to four more divergent lineages. This suggests that in contrast to previous expectations, the Horn of Africa is a hot spot of plastid diversity but not the ancestral origin for present populations of P. africana. The ratio between pollen to seed flow was estimated to be 7.1, indicating predominant gene flow by pollen. The exhaustive pollen flow also facilitated gene exchange with West African nuclear lineages probably in the early Holocene. The Ethiopian rift formed a genetic barrier resulting in population differentiation east and west of the rift; however, it was less effective in disrupting gene flow than the Eastern Rift in more southern parts of the East African range.
A study on four commonly found indigenous coffee shade tree species (Acacia abyssinica, Albizia g... more A study on four commonly found indigenous coffee shade tree species (Acacia abyssinica, Albizia gummifera, Albizia schimperiana, and Cordia africana) was conducted in the Afromontane rainforests of Ethiopia to assess their effects on the physical and sensory quality of wild Arabica coffee. Results showed that sensorial differences in wild Arabica coffees were detected due to tree species. Tree species significantly affected beverage acidity, flavour, aftertaste and overall cup quality. This means coffee samples collected under A. abyssinica and C. africana were more acidic, with better flavour and overall cup quality as compared to those collected under both Albizia species. But no apparent difference in body of the brew could be detected due to tree species. Moreover, the proportion of marketable beans (screen 14 plus in Ethiopian case) was higher under Acacia (92.73%) and Cordia (91.79%) than under A. schimperiana (89.48%) and A. gummifera (88.42%). To the contrary, the proportion of very small beans (which are rejects in most cases) was significantly higher under A. gummifera and A. schimperiana than under Acacia or Cordia. Generally, coffee beverages prepared from samples under Acacia and Cordia were more appreciated by the tasters than those under both Albizia species. This finding coincides well with the local farmers’ perception for Acacia, but not for Cordia. In Ethiopia, C. africana is a valuable timber tree but endangered species, and hence its positive effect on coffee quality as obtained by the present finding is an added advantage. In light of the present findings, the practical significance of the study in terms of shade coffee production and biodiversity conservation are discussed.
Background: Korarima [Aframomum corrorima (Braun) P.C.M. Jansen] is a spice crop native to Ethiop... more Background: Korarima [Aframomum corrorima (Braun) P.C.M. Jansen] is a spice crop native to Ethiopia. Understanding the extent and partitioning of diversity within and among crop landraces and their wild relatives is among the first steps in conserving and measuring their genetic potential. The present study is aimed at characterizing the population genetic structure and relationships between cultivated and wild korarima in the southwestern part of Ethiopia. Results: We analyzed a total of 195 individuals representing seven wild and fourteen cultivated populations. Eleven polymorphic simple sequence repeat (SSR) markers were used. We observed a total of 53 alleles across the eleven loci and individuals. In total, 32 alleles were detected in the cultivated populations, whereas 49 alleles were detected in the wild populations. We found higher genetic diversity in wild populations than in the cultivated counterpart. This result implies the potential of wild korarima as a possible source for novel alleles contributing to the improvement of cultivated korarima. Analysis of molecular variance (AMOVA) showed significant but low differentiation between cultivated and wild korarima populations. Similarly, neighbour-joining and STRUCTURE analyses did not group cultivated and wild populations into two distinct clusters. The lack of clear differentiation between cultivated and wild populations could be explained by historical and contemporary gene flow between the two gene pools. Conclusion: The 11 SSR loci developed in this study could be employed to examine genetic diversity and population structure of korarima in other countries as well as other Aframomum species. From the five administrative zones considered in this study, the Bench-Magi and Sheka zone showed populations with high genetic diversity, and these populations could be used as a potential starting point for in-situ and ex-situ germplasm conservation and korarima improvement through breeding programs after proper agronomic evaluation.
Neighbor-joining tree based on pair-wise simple matching dissimilarity index showing the genetic ... more Neighbor-joining tree based on pair-wise simple matching dissimilarity index showing the genetic relationships among 101 individuals randomly re sampled from cultivated and wild korarima populations (19 populations were represented by five samples each and two populations were represented by three samples each). Blue color indicates individuals from cultivated populations whereas red represents individuals from wild populations. (DOCX 22 kb)
A biplot detected the maximum peak at KÂ =Â 2 (the optimum number of clusters) based on Evanno et... more A biplot detected the maximum peak at KÂ =Â 2 (the optimum number of clusters) based on Evanno et al. 2005 [35] prediction. (PDF 10Â kb)
The rich linguistic, ethnic and cultural diversity of Ethiopia provides an unprecedented opportun... more The rich linguistic, ethnic and cultural diversity of Ethiopia provides an unprecedented opportunity to understand the level to which cultural factors correlate with–and shape–genetic structure in human populations. Using primarily new genetic variation data covering 1,214 Ethiopians representing 68 different ethnic groups, together with information on individuals’ birthplaces, linguistic/religious practices and 31 cultural practices, we disentangle the effects of geographic distance, elevation, and social factors on the genetic structure of Ethiopians today. We provide evidence of associations between social behaviours and genetic differences among present-day peoples. We show that genetic similarity is broadly associated with linguistic affiliation, but also identify pronounced genetic similarity among groups from disparate language classifications that may in part be attributable to recent intermixing. We also illustrate how groups reporting the same culture traits are more genet...
Background: Emerging wheat stem rust races have become a major threat to global wheat production.... more Background: Emerging wheat stem rust races have become a major threat to global wheat production. Finding additional loci responsible for resistance to these races and incorporating them into currently cultivated varieties is the most economic and environmentally sound strategy to combat this problem. Thus, this study was aimed at characterizing the genetic diversity and identifying the genetic loci conferring resistance to the stem rust of wheat. To accomplish this, 245 elite lines introduced from the International Center for Agricultural Research in the Dry Areas (ICARDA) were evaluated under natural stem rust pressure in the field at the Debre Zeit Agricultural Research Center, Ethiopia. The single nucleotide polymorphisms (SNP) marker data was retrieved from a 15 K SNP wheat array. A mixed linear model was used to investigate the association between SNP markers and the best linear unbiased prediction (BLUP) values of the stem rust coefficient of infection (CI). Results: Phenotypic analysis revealed that 46% of the lines had a coefficient of infection (CI) in a range of 0 to 19. Genome-wide average values of 0.38, 0.20, and 0.71 were recorded for Nei's gene diversity, polymorphism information content, and major allele frequency, respectively. A total of 46 marker-trait associations (MTAs) encompassed within eleven quantitative trait loci (QTL) were detected on chromosomes 1B, 3A, 3B, 4A, 4B, and 5A for CI. Two major QTLs with-log 10 (p) ≥ 4 (EWYP1B.1 and EWYP1B.2) were discovered on chromosome 1B. Conclusions: This study identified several novel markers associated with stem rust resistance in wheat with the potential to facilitate durable rust resistance development through marker-assisted selection. It is recommended that the resistant wheat genotypes identified in this study be used in the national wheat breeding programs to improve stem rust resistance.
Ethiopian Journal of Applied Science and Technology, 2020
The study was conducted in the natural coffee forest ecosystems of southwest and southeast Ethiop... more The study was conducted in the natural coffee forest ecosystems of southwest and southeast Ethiopia, where the wild populations of Coffea arabica L. naturally grow. Soil is an important environmental factor that performs different important functions in the terrestrial ecosystems, including in the natural coffee forest ecosystems. The objective of this study was to investigate the link between soil properties and bean quality of wild Arabica coffee in the natural coffee forests of Ethiopia. Data on soil parameters and bean characteristics were assessed. Results from simple correlation analysis, stepwise regression analysis and ordination analysis (principal component analysis-PCA, redundancy analysis-RDA) showed that bean size distribution of wild Arabica coffee was clearly related to the soil characteristics of the natural coffee forest ecosystem. Monte Carlo permutation test for the first RDA axis was significant (p=0.0020) with 499 permutations. Forward selection procedure showed that soil pH, Mn, sand, Na, available P and organic matter (OM) significantly contributed to the variability in bean size distribution of wild Arabica coffee. Soil parameters such as soil pH, Mn, pH, CEC, OM, total N, Ca, Na and pH relatively favoured the development of larger beans, whereas higher available P, K and silt contributed to the development of smaller beans. Moreover, the first RDA axis clearly discriminated coffee samples of the southeast coffee forests from those of the southwest coffee forests, and the variation in bean characteristics clearly followed the trend of soil characteristics. Thus, soil is an important environmental factor for the physical quality of wild Arabica coffee.
The present study aimed to examine the PTC tasting ability in selected individuals from Ethiopia.... more The present study aimed to examine the PTC tasting ability in selected individuals from Ethiopia. It involved 465 participants representing four ethnic groups. A total of 69 individuals from Amhara (30 females and 39 males), 52 from Agnuak (3 females and 49 males), 59 from Nuer and 285 (60 females and 225 males) from Oromo were recruited. The investigation was made using a series of graded concentrations of PTC dissolved in pure water and the results were recorded. The participants were analyzed for the distribution of tasters and non-tasters for PTC. The frequency of dominant and recessive alleles of PTC gene was calculated using Hardy-Weinberg methods. The result showed that the frequency of tasters (82.80%) were significantly higher than that of non-tasters (17.20%) in all populations. Likewise, frequency of tasters among males (83.06%) and females (82.61%) were significantly higher than the frequency of non-taster males (16.94%) and females (17.39%). This shows that PTC tasting ...
Crop production is the main source of food, and drought is among the most important crop producti... more Crop production is the main source of food, and drought is among the most important crop production constraints in the world, particularly in sub-Saharan Africa. The use of improved cultivars can at least partly ameliorate the calamities of drought stress, and considerable investments and efforts have been made worldwide to develop drought tolerant crop cultivars. A number of improved cultivars of different crops have also been released for production in different countries. As related to the situation under normal environments, it is yet hardly possible to say that these investments and efforts have modernized the production under drought-prone environments as a whole and boosted the actual productivity as desired. Therefore, the limitations and strategic implications of past experiences made to develop drought tolerant crop cultivars needs to be synthesized in order to formulate better strategies and approaches. In this review article, the scope and impacts of drought, approaches ...
Coffee quality is a complex trait involving sensory and bean characteristics as well as biochemic... more Coffee quality is a complex trait involving sensory and bean characteristics as well as biochemical contents. The objective of this study was to assess the major factors influencing the quality of wild Arabica coffee (Coffea arabica L.) in the natural coffee forests of southwest and southeast Ethiopia. Results revealed that both natural (soil, aspect, elevation, climate, geographic location) and human factors (cherry harvesting/ handing, theft, forest management) considerably influenced the quality of wild Arabica coffee. The soil factor affected every component of coffee quality (cup quality, bean characteristics and biochemical contents). The cup quality of coffee varied with soil properties, especially with available P and soil texture. The bean size distribution was also affected by soil properties; there was significant positive relationship between soil pH, sand or Mn and the proportion of bold beans (retained on screen 17). Soil organic matter, total N and sand content were inversely correlated with caffeine content, but available P and clay content were positively correlated with caffeine. Increase in elevation led to increase in bean size up to the elevation of about 1600 m above sea level, but thereafter no more increase in bean size (hump-shaped relationship, not monotonic). Bean size increased with increase in longitude, but it decreased with increase in latitude. Cup quality was also significantly influenced by coffee harvesting and handling, but its influence was not noticed on bean size and biochemical contents. Coffee quality is therefore the resultant of an interaction of different natural and human factors prevailing in the respective area.
The human FMO2 (flavin-containing monooxygenase 2) gene has been shown to be involved in innate i... more The human FMO2 (flavin-containing monooxygenase 2) gene has been shown to be involved in innate immunity against microbial infections, including tuberculosis (TB), via the modulation of oxidative stress levels. It has also been found to possess a curious loss-offunction mutation (FMO2*1/FMO2*2) that demonstrates a distinctive differentiation in expression, function and ethno-geographic distribution. However, despite evidences of ethnic-specific genetic associations in the inflammatory profile of TB, no studies were done to investigate whether these patterns of variations correlate with evidences for the involvement of FMO2 in antimicrobial immune responses and ethnic differences in the distribution of FMO2 polymorphisms except for some pharmacogenetic data that suggest a potentially deleterious role for the functional variant (FMO2*1). This genetic epidemiological study was designed to investigate whether there is an association between FMO2 polymorphisms and TB, an ancient malady that remains a modern global health concern, in a sub-Saharan Africa setting where there is not only a relatively high co-prevalence of the disease and the ancestral FMO2*1 variant but also where both Mycobcaterium and Homo sapiens are considered to have originated and co-evolved. Blood samples and TB related clinical data were collected from ascertained TB cases and unrelated household controls (n = 292) from 3 different ethnic groups in Ethiopia. Latent Mtb infection was determined using Quantiferon to develop reliable TB progression phenotypes. We sequenced exonic regions of FMO2.We identified for the first time an association between FMO2 and TB both at the SNP and haplotype level. Two novel SNPs achieved a study-wide significance [chr1:171181877(A), p = 3.15E-07, OR = 4.644 and chr1:171165749(T), p = 3.32E-06, OR = 6.825] while multiple SNPs (22) showed nominal signals. The pattern of association suggested a protective effect of FMO2 against both active and latent TB with distinct genetic variants underlying the TB
The journal implements double-blind peer review practiced by specially invited international edit... more The journal implements double-blind peer review practiced by specially invited international editorial board members. [2] that bring about three phenotypic classes: Hp 1-1 , Hp 1-2 and Hp 2-2. Haptoglobin gene is principally expressed in the liver by hepatocytes[3], induced by cytokines such as interleukin-6 (IL-6), IL-1 and tumor necrosis factor-α (TNF-α)[4]. Structurally, it has four chains: 2α light chains and 2β heavy chains[5], and following its secretion, circulates as a linear dimer, or as a linear polymer, or as a cyclic polymer. In healthy human adults, plasma Hp level varies between 0.38 g/L and 2.08 g/L[6], but the range may elevate in response to inflammation, bacterial infection, tissue destruction and malignant diseases[4,7]. Besides its hemoglobin scavenging role, Hp has many biological functions such as oxidative stress prevention[8], anti-oxidant function[9], nitric oxide related function[10], antibacterial activities[6], renal damage prevention[6,8], antiinflammatory functions[8], inhibition of prostaglandin synthesis[11], and immune modulation[8,12]. The modulation function of Hp both
Abstract According to Food and Agriculture Organization (FAO), droughts have significant economic... more Abstract According to Food and Agriculture Organization (FAO), droughts have significant economic, environmental, and social impacts, both direct and indirect. All field crops are affected by drought. Global warming and climate change are expected to exacerbate this phenomenon. Barley (Hordeum vulgare L.) ranks fourth among cereals after wheat (Triticum aestivum L.), maize (Zea mays L.), and rice (Oryza sativa L.). Drought is a significant issue in barley breeding programs. The purpose of this chapter is to review pertinent literature on general drought-tolerance mechanisms in important field crops and provide the latest state-of-the-art information on drought-coping mechanisms in barley, including molecular basis of crop response in moisture-limited environments. We highlight research insights, existing gaps, and future research directions regarding drought tolerance in barley. Known quantitative trait loci (QTL) and genes, such as Dhn and DREB, and their use in marker-assisted selection for drought tolerance are summarized. Traits associated with improved performance (early vigor, plant height, spike waxiness, and thousand-grain weight) under low-moisture stress environments have been identified as useful criteria in breeding for drought-tolerant barley. Low stomatal density cultivars of barley should be developed to combat drought and climate change. Latest innovations in genome-editing technology, such as clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9), clustered regularly interspaced short palindromic repeats from Prevotella and Francisella 1 (CRISPR-Cpf1), and multiplexed accurate genome editing with short, trackable, integrated cellular barcodes (MAGESTIC), should be useful for plant breeders in modifying the barley genome, as needed, to develop drought-tolerant cultivars.
We studied the genetic pattern of 21 Ethiopian populations of Prunus africana by using six nuclea... more We studied the genetic pattern of 21 Ethiopian populations of Prunus africana by using six nuclear and five plastid microsatellites. In total, 89 alleles were found in the nuclear and 16 haplotypes in the plastid genome. High levels of diversity both in cpSSRs (hT = 0.703) and nSSR (HT = 0.725) were detected. Genetic differentiation among populations at the nuclear and plastid level was moderate (FST = 0.122 vs. GST = 0.478). While Ethiopian populations harbored the highest plastid haplotype diversity throughout Africa, the level of nuclear diversity was lower than in the remaining part of the species’ range. Ten of the observed 16 plastid haplotypes were unique to Ethiopia, suggesting an isolated plastid evolution. Remarkably, all plastid haplotypes found in Ethiopia belonged to one single lineage, while other populations from East Africa and Madagascar contain haplotypes from up to four more divergent lineages. This suggests that in contrast to previous expectations, the Horn of Africa is a hot spot of plastid diversity but not the ancestral origin for present populations of P. africana. The ratio between pollen to seed flow was estimated to be 7.1, indicating predominant gene flow by pollen. The exhaustive pollen flow also facilitated gene exchange with West African nuclear lineages probably in the early Holocene. The Ethiopian rift formed a genetic barrier resulting in population differentiation east and west of the rift; however, it was less effective in disrupting gene flow than the Eastern Rift in more southern parts of the East African range.
A study on four commonly found indigenous coffee shade tree species (Acacia abyssinica, Albizia g... more A study on four commonly found indigenous coffee shade tree species (Acacia abyssinica, Albizia gummifera, Albizia schimperiana, and Cordia africana) was conducted in the Afromontane rainforests of Ethiopia to assess their effects on the physical and sensory quality of wild Arabica coffee. Results showed that sensorial differences in wild Arabica coffees were detected due to tree species. Tree species significantly affected beverage acidity, flavour, aftertaste and overall cup quality. This means coffee samples collected under A. abyssinica and C. africana were more acidic, with better flavour and overall cup quality as compared to those collected under both Albizia species. But no apparent difference in body of the brew could be detected due to tree species. Moreover, the proportion of marketable beans (screen 14 plus in Ethiopian case) was higher under Acacia (92.73%) and Cordia (91.79%) than under A. schimperiana (89.48%) and A. gummifera (88.42%). To the contrary, the proportion of very small beans (which are rejects in most cases) was significantly higher under A. gummifera and A. schimperiana than under Acacia or Cordia. Generally, coffee beverages prepared from samples under Acacia and Cordia were more appreciated by the tasters than those under both Albizia species. This finding coincides well with the local farmers’ perception for Acacia, but not for Cordia. In Ethiopia, C. africana is a valuable timber tree but endangered species, and hence its positive effect on coffee quality as obtained by the present finding is an added advantage. In light of the present findings, the practical significance of the study in terms of shade coffee production and biodiversity conservation are discussed.
Background: Korarima [Aframomum corrorima (Braun) P.C.M. Jansen] is a spice crop native to Ethiop... more Background: Korarima [Aframomum corrorima (Braun) P.C.M. Jansen] is a spice crop native to Ethiopia. Understanding the extent and partitioning of diversity within and among crop landraces and their wild relatives is among the first steps in conserving and measuring their genetic potential. The present study is aimed at characterizing the population genetic structure and relationships between cultivated and wild korarima in the southwestern part of Ethiopia. Results: We analyzed a total of 195 individuals representing seven wild and fourteen cultivated populations. Eleven polymorphic simple sequence repeat (SSR) markers were used. We observed a total of 53 alleles across the eleven loci and individuals. In total, 32 alleles were detected in the cultivated populations, whereas 49 alleles were detected in the wild populations. We found higher genetic diversity in wild populations than in the cultivated counterpart. This result implies the potential of wild korarima as a possible source for novel alleles contributing to the improvement of cultivated korarima. Analysis of molecular variance (AMOVA) showed significant but low differentiation between cultivated and wild korarima populations. Similarly, neighbour-joining and STRUCTURE analyses did not group cultivated and wild populations into two distinct clusters. The lack of clear differentiation between cultivated and wild populations could be explained by historical and contemporary gene flow between the two gene pools. Conclusion: The 11 SSR loci developed in this study could be employed to examine genetic diversity and population structure of korarima in other countries as well as other Aframomum species. From the five administrative zones considered in this study, the Bench-Magi and Sheka zone showed populations with high genetic diversity, and these populations could be used as a potential starting point for in-situ and ex-situ germplasm conservation and korarima improvement through breeding programs after proper agronomic evaluation.
Neighbor-joining tree based on pair-wise simple matching dissimilarity index showing the genetic ... more Neighbor-joining tree based on pair-wise simple matching dissimilarity index showing the genetic relationships among 101 individuals randomly re sampled from cultivated and wild korarima populations (19 populations were represented by five samples each and two populations were represented by three samples each). Blue color indicates individuals from cultivated populations whereas red represents individuals from wild populations. (DOCX 22 kb)
A biplot detected the maximum peak at KÂ =Â 2 (the optimum number of clusters) based on Evanno et... more A biplot detected the maximum peak at KÂ =Â 2 (the optimum number of clusters) based on Evanno et al. 2005 [35] prediction. (PDF 10Â kb)
The rich linguistic, ethnic and cultural diversity of Ethiopia provides an unprecedented opportun... more The rich linguistic, ethnic and cultural diversity of Ethiopia provides an unprecedented opportunity to understand the level to which cultural factors correlate with–and shape–genetic structure in human populations. Using primarily new genetic variation data covering 1,214 Ethiopians representing 68 different ethnic groups, together with information on individuals’ birthplaces, linguistic/religious practices and 31 cultural practices, we disentangle the effects of geographic distance, elevation, and social factors on the genetic structure of Ethiopians today. We provide evidence of associations between social behaviours and genetic differences among present-day peoples. We show that genetic similarity is broadly associated with linguistic affiliation, but also identify pronounced genetic similarity among groups from disparate language classifications that may in part be attributable to recent intermixing. We also illustrate how groups reporting the same culture traits are more genet...
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Papers by Endashaw Bekele