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 ...
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.
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...
21st International Conference on Coffee Science, Montpellier, France, 11-15 September, 2006., 2007
... GKTESFAYE 1,2 , K. GOVERS 2 , T. OLJIRA 1 , E. BEKELE 1 AND T. BORSCH 2 ... Work on nuclear m... more ... GKTESFAYE 1,2 , K. GOVERS 2 , T. OLJIRA 1 , E. BEKELE 1 AND T. BORSCH 2 ... Work on nuclear microsatellites with the aim to establish a co-dominant marker system that allows to assess heterozygosity and gene flow in wild Coffea is in progress. ...
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 ...
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.
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...
21st International Conference on Coffee Science, Montpellier, France, 11-15 September, 2006., 2007
... GKTESFAYE 1,2 , K. GOVERS 2 , T. OLJIRA 1 , E. BEKELE 1 AND T. BORSCH 2 ... Work on nuclear m... more ... GKTESFAYE 1,2 , K. GOVERS 2 , T. OLJIRA 1 , E. BEKELE 1 AND T. BORSCH 2 ... Work on nuclear microsatellites with the aim to establish a co-dominant marker system that allows to assess heterozygosity and gene flow in wild Coffea is in progress. ...
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