Field experimental details are the same as those outlined in Paper 1. Data on chocolate spot (Bot... more Field experimental details are the same as those outlined in Paper 1. Data on chocolate spot (Botrytis fabae) in faba bean and Aschochyta blight (Mycosphaerella pinodes) in field pea were recorded based on a 1-9 scale and analyzed. The result showed highly significant differences among the treatments, between years and locations and their interaction effects in most of the cases. Mixed-cropping did not exclude the occurrence of both diseases, the incidences of which were relatively higher at Holetta than at Denbi. Chocolate spot at Denbi and Ascochyta blight in field pea at both locations also significantly differed between the systems. Faba bean varieties Mesay and NC 58 were more affected by chocolate spot under both systems. However, mixed production of the two crops favored incidence of chocolate spot in faba bean and disfavored Ascochyta blight maybe due to changes in the microenvironment associated with changes in the cropping systems. Field pea as an intercrop may reduce free...
Breeding of Abyssinian field pea (Pisum sativum var. Abyssinicum) genotypes effective forbiologic... more Breeding of Abyssinian field pea (Pisum sativum var. Abyssinicum) genotypes effective forbiological nitrogen fixation (BNF) has considerable economic and ecological significance. Anexperiment was conducted to study the magnitude of genetic diversity for attributes ofbiological nitrogen fixation. The experiment was carried out in 2007 in the greenhouse onVertisol and Nitisol soils at Addis Ababa University using a randomized complete block designwith three replications, where the Nitrogen difference technique with Yellow Dodolla, a varietyof Brassica carinata A Braun as a reference crop, was used to estimate the proportions of nitrogenderived from soil and atmosphere. Differences among the accessions for 14 traits studied weresignificant on both soil types. However, genotype by soil type interaction effects were significantonly for early vigor, number of nodules, nodule dry weight, foliage phosphorus content (%),phosphorus derived from fertilizer (%) and phosphorus uptake efficiency (%). This indicatedthat the two soils were distinctly different or the accessions responded differently to soil type forthese traits. Cluster analysis for average performances on the two soils grouped the accessionsinto four different classes, and Mahalanobis’s D 2 analyses showed significant genetic distancesbetween most of the clusters. Five accessions, namely MColl-7/07, MColl-8/07, TKColl-6/07,MCColl-4/07 and TKColl-3/07 were identified as best fixers of nitrogen under both Vertisol andNitisol soils with a fixation range of 41- 45 % and these accessions could be exploited in futurebreeding endeavors to develop BNF efficient genotypes. Additionally, there was no clearinterrelationship between the origins of accessions and the pattern of genetic diversity as therewere genotypes from the same source of origin fell into different clusters and vice versa.
A study was conducted to determine the optimum lime/CaCO<sub>3</sub> rate and incubat... more A study was conducted to determine the optimum lime/CaCO<sub>3</sub> rate and incubation period and exchangeable acidity equivalence for the amelioration of acidic nitisols collected from the central highlands of Ethiopia. A pot experiment was conducted at Holeta Agricultural Research Centre (HARC) in lath house using acidic soil samples collected from a depth of 0-20 cm from Bedi area, central high lands of Ethiopia. The treatments consisted of factorial combination of lime rates (0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 mg kg soil) and different incubation periods (7, 14, 21, 28, 35, 42 days). The treatments were arranged in RCBD with two replications. The result of the study showed that the soil pH consistently increased with the increase in lime application rates. There is no clear trend of incubation period effect on soil pH but higher pH was recorded after four weeks of incubation following lime application indicating that lime incubation period for o...
African Journal of Environmental Science and Technology, 2015
Many people in Africa depend on water from borehole, but purity of the drinking water from this s... more Many people in Africa depend on water from borehole, but purity of the drinking water from this source remains questionable. In a bid to ascertain the health risk local people are exposed to, this study analyses the physico-chemical characteristics of borehole water in Gassol Local Government Area (LGA), Nigeria. For this purpose, water samples were collected from the 12 administrative wards in the LGA. Two samples were collected from each ward, one in the rainy season (March) and another in the dry season (November), a total of 24 water samples in all. The water samples were analyzed for 18 different physical and chemical parameters to ascertain their comparability with the guideline levels recommended by the Standard Organization of Nigeria (SON) and World Health Organization (WHO). Results show that most parameters were within the guideline values in both seasons except for turbidity, pH, fluoride (F-), chlorine (Cl +), iron (Fe 2+), ammonia (NH 4 +) and manganese (Mn 2 +). Overall, all of the wards had at least one instance in which a parameter falls outside recommended guideline. A further analysis using the mean value test approach to assess level of contamination relative to guideline values showed that the upper bound value (US 95) of turbidity, iron, pH and chlorine are greater than their guideline values. This indicates that these are the parameters for which the most urgent action is needed. The high concentration of iron and turbidity outside the prescribed limits in the rainy season suggests that water managers need pay more attention to borehole water quality in the rainy season. There is need for further research across the region to better understand the quality and the contaminants (natural and anthropogenic) of borehole water so as to be able to proffer appropriate remediation strategy.
Finger millet (Eleusine coracana L.) is one of the important indigenous crops of Africa. The prod... more Finger millet (Eleusine coracana L.) is one of the important indigenous crops of Africa. The productivity of the crop, however, is very low owing to several factors including the inherent low-yielding potential of the cultivars. Information on genetic diversity among the available germplasm collections is very useful for breeding programs utilizing the materials as germplasm source. An experiment was conducted at Arsi Negele and Bako, Ethiopia, in 2000 main season to study the extent of genetic variability present among sixty-four germplasm accessions collected from the Eastern and Southern Africa and maintained at the Institute of Biodiversity Conservation, Ethiopia. The accessions were planted in three replications at both locations using a randomized complete block design. Data were recorded on eleven morpho-agronomic characters. Analysis of variance at both locations showed that the mean squares due to genotype and genotype by location interaction were significant (P < 0.05) in almost all the cases. Broad-sense heritability values at each location and combined over locations were higher (> 80%) for most of the characters, indicating the existence of a wealth of genetic variability among the population for most of the morpho-agronomic traits. Cluster analysis grouped the accessions into four clusters of different sizes. It appears that geographical origin has no or little effect in determining the pattern of genetic diversity observed among the accessions. The greatest variability among accessions was observed for characters such as biomass, ear weight and grain weight, which highly dictated the differentiation of accessions into clusters. Genetic distances between cluster IV and all other clusters were significant indicating that crosses between selection from members of cluster IV with the rest of the clusters may provide desirable recombinant in breeding efforts. Parental selection should also be based on the existence of optimum level of the desired traits.
This study was undertaken to evaluate the extent and pattern of genetic diversity for immature po... more This study was undertaken to evaluate the extent and pattern of genetic diversity for immature pod traits in Ethiopia cowpea landrace collections. Eighty one landraces and improved cultivars were tested in a 9 x 9 simple lattice design. Analysis of variance revealed highly significant (P<0.01) or significant (p<0.05) differences among the genotypes for all traits. The first four principal components were able to explain 81% of variation for quantitative traits and 76% for qualitative traits. The genotypes were grouped into three distinct clusters, the first, second and third clusters with 60, 15 and 25% of the genotypes in that order. The landraces were distributed all over the clusters while the improved cultivars were absent in the second cluster. Shannon-Weaver diversity indices also showed existence of adequate genetic variability among the genotypes for qualitative traits. Shannon-Weaver diversity indices ranged from the lowest of 0.50 for pod curvature to the highest of 0.99 for pod shape. The study clearly showed that, even if the genotypes were classified into a few cluster, there was adequate divergence among the clusters showing existence of considerable genetic variability for immature pod traits for exploitation in future breeding for better green pod yield and quality in cowpea.
Fourteen field pea genotypes were evaluated at 16 environments in Ethiopia during 2007 and/or 200... more Fourteen field pea genotypes were evaluated at 16 environments in Ethiopia during 2007 and/or 2008 main cropping seasons. The objective of the study was to determine the magnitude of genotype × environment interaction and performance stability in the field pea genotypes. The study was conducted using a randomized complete block design with 4 replications. Genotype × environment interaction and yield stability were estimated using the additive main effects and multiplicative interaction and site regression genotype plus genotype × environment interaction biplot. Pooled analysis of variance for grain yield showed significant (p<0.01) differences among the genotypes, environments and the genotype × environment interaction effects. This indicated that the genotypes differentially responded to the changes in the test environments or the test environments differentially discriminated the genotypes or both. Environment accounted for 74.3% of the total yield variation, genotype for 4.2% and genotype × environment for 16.4%, indicating the need for spatial and temporal replication of variety trials. The first five bilinear terms of AMMI were found to be significant. The first two multiplicative component terms sum of squares, with their cumulative degrees of freedom of 52, explained 69.1% of the interaction sum of squares. No single variety showed a superior performance in all the environments but genotype EH02-036-2, followed by Coll.026/01-4, demonstrated top ranking at five of the sixteen environments. The application of AMMI and GGE biplots facilitated the visual comparison and identification of superior genotypes, thereby supporting decisions on variety selection and recommendation in different environments.
Ethiopia is considered an important center of secondary diversity for both faba bean (Vicia faba ... more Ethiopia is considered an important center of secondary diversity for both faba bean (Vicia faba L.) and field pea (Pisum sativum L.). However, areas of eco-geographic distribution and the microcenter of genetic diversity are not well known. Two separate trials consisting of 160 faba bean and 148 field pea accessions were conducted at Holetta and Kulumsa in 2001. Simple and alpha-lattice designs with 2 replications were used for faba bean and field pea, respectively. Cluster analysis grouped faba bean accessions into eight and field pea into five different classes. Mahalanobis's D 2 analyses showed significant genetic distances between most of the clusters in both crops. Accessions from the northern parts of the country showed tendencies of being grouped together, indicating that their genetic background may be related. Accessions from the southern parts of the country were distributed over most of the clusters showing more genetic diversity compared to those from the northern parts. This indicates that the distribution of genetic diversity among accessions is not uniform across different eco-geographical regions in Ethiopia and the microcenter of genetic diversity for both crops may be located in the southern part of the country. The existence of more genetic diversity in one region compared to the other could be due to differences in the level of variability among the original introductions to different regions, the nature and degree of both human and natural selections after introduction, and effects of ecological and agricultural conditions as major forces of evolution. Future collection, conservation and utilization programs should focus on the southern part to safeguard and exploit the tremendous genetic diversity. However, a comprehensive study involving both morpho-agronomic traits and molecular markers would be needed for a more comprehensive conclusion.
Plant breeding is one way to confront the challenge of bridging the widening gap between the dema... more Plant breeding is one way to confront the challenge of bridging the widening gap between the demand and supply of food. Despite the importance, however, plant breeding has its own negative side effects. The replacement of landraces with a few genetically uniform varieties depletes genetic diversity and provides ideal conditions for diseases and insect pests that called genetic vulnerability. The increasingly growing human population and the subsequently rising demands for more food, on the one hand, and the success of such efforts like the "Green Revolution" from adoption of genetically uniform varieties in many parts of the world, on the other, are the main driving force towards this narrow genetic base. It is, therefore, important to understand the phenomena and plan to minimize the risks from genetic vulnerability. Under marginal conditions where resource-poor farmers dominate, the current plant breeding strategies, variety release, registration and certification procedures leading to genetic uniformity should be reconsidered and some level of genetic diversity should deliberately be maintained in variety development programs. Genetic diversity can be introduced at different levels and in different ways which may include intra-varietal, inter-varietal, inter-parental and inter-specific diversities. Breeding for specific adaptation instead of wide adaptation, systematic spatial and temporal gene deployment, use of inter-specific varietal mixtures and integration of horizontal and vertical resistances have been suggested as solutions.
Crop production plays a significant role in the Ethiopian economy. The sub-sector's output has, h... more Crop production plays a significant role in the Ethiopian economy. The sub-sector's output has, however, been very low partially due to the biophysical challenges constraining productivity in smallholder farms and inadequate technological interventions. Genetic modification of crops to improve productivity is preferred to the continual manipulation of the growing environment because of cost particularly to the large majority of resource-poor farmers who cannot afford for production inputs. Consideration of varietal selection vis-à-vis actual target production environment is vital to maximizing gains from breeding efforts. The tradition across most of the breeding programs in Ethiopia is to develop varieties under optimum management despite the fact that marginal management characterizes the ultimate target production environments. Whether selection under optimum management is likely to result in better productivity gain than under the actual target production environments is a crucial issue in varietal development. This paper discusses the logical framework for breeding success and the conventional approach to varietal selection and its challenges in Ethiopia. Based on the analyses, the paper proposes that the wheel of the current variety development schemes should be redirected and made more objective and focused towards better serving the major target beneficiaries, i.e. the resource-poor farmers.
... AGRIS 2011 - FAO of the United Nations. Related AGRIS Results: -, Assessment of losses in yie... more ... AGRIS 2011 - FAO of the United Nations. Related AGRIS Results: -, Assessment of losses in yield and yield components of maize varieties due to grey leaf spot by Dagene Wegary; Demissew Kitaw; Girma Demissie (2004) in English. ...
International Journal of Sustainable Agricultural Research
Chickpea is one of the most cultivated grain legumes in Ethiopia for grain production and amelior... more Chickpea is one of the most cultivated grain legumes in Ethiopia for grain production and amelioration of soil fertility with less attention in research on N-fixation. Therefore, this study was conducted to estimate the magnitude of heterosis for nitrogen fixation and yield and yield associated traits in chickpea (Cicer arietinum L.). Six F1 crosses obtained from crossing of four parents (two nodulated and non-nodulated) in a half diallel fashion were evaluated in 2014/15 season in lath house using Randomized Complete Block Design (RCBD) with two replications at Debre Zeit Agricultural Research Center. Significant (P<0.05) differences were exhibited among entries for all traits studied. Considering all traits, relative to the mid parent (MPH), better parent (BPH) and standard heterosis (SH) in percent ranged from 0.009 to 59.8, 0.009 to39.9 and 0.009 to58.8, respectively. The highest degrees of MPH were noted for nodule dry weight and of BPH and SH were noted for number of pods per plant, while the lowest was observed for grain yield (0.009). The hybrid obtained from nodulated parents (ICC5003 x ICC19180) showed high heterosis for number of nodule on the basis of MPH and BPH, while ICC4918x ICC19181 exhibited low heterotic effect which exhibited positive and significant MPH for nitrogen fixed in grain, BPH for seed filling duration and SH for days to 50% flowering, days to 90% maturity and shoot dry weight at maturity traits. 1. INTRODUCTION Chickpea (Cicer arietinum L.) is one of the most important food legume crops widely produced-globally on over 12 million hectares of land from which 10.9 million tons of grain is produced every year (FAOSTAT, 2012). It ranks second in area coverage (15.3% of the total area allotted to food legumes) and third in volume of production (14.6%) after common beans (Phaseolus vulgaris L.) and field peas (Pisum sativum L.) (Knights et al., 2007). In Ethiopia chickpea production ranks third in area and production among legumes next to faba bean and haricot bean (CSA, 2014/15). Out of 1.6 million hectares allocated for pulse , chickpea covered 239,755 hectares of land from
Eleven faba bean (Vicia faba L.) varieties released between 1977 and 2007, and two promising geno... more Eleven faba bean (Vicia faba L.) varieties released between 1977 and 2007, and two promising genotypes, were evaluated to estimate the genetic progresses made in 33 years of faba bean breeding in Ethiopia. The study was conducted at eight environments during 2007 and 2009 cropping seasons in a randomized complete block design with four replications. Records taken on grain yield, seed size and chocolate spot (Botrytis fabae) severity were subjected to statistical analysis. Combined analysis of variance revealed highly significant differences among the genotypes and the test environments for all traits, the G × E interaction effects being significant for grain yield and seed size. Regression of mean performance at all environments on year of varietal release showed positive relationship for grain yield (r = 0.48) and seed size (r = 0.80**) but negative for chocolate spot (r = -0.60*). The annual rates of genetic progresses were 8.74 kg ha -1 , 8.07 g 1000 seeds -1 and -0.27% for grain...
Cowpea [Vigna unguiculata (L.) Walp] is one of the important climate-resilient legume crops for f... more Cowpea [Vigna unguiculata (L.) Walp] is one of the important climate-resilient legume crops for food and nutrition security in sub-Saharan Africa. Ethiopia is believed to harbor high cowpea genetic diversity, but this has not yet been efficiently characterized and exploited in breeding. The objective of this study was to evaluate the extent and pattern of genetic diversity in 357 cowpea accestions comprising landraces (87%), breeding lines (11%) and released varieties (2%), using single nucleotide polymorphism markers. The overall gene diversity and heterozygosity were 0.28 and 0.12, respectively. The genetic diversity indices indicated substantial diversity in Ethiopian cowpea landraces. Analysis of molecular variance showed that most of the variation was within in the population (46%) and 44% between individuals, with only 10% of the variation being among populations. Model-based ancestry analysis, the phylogenetic tree, discriminant analysis of principal components and principal coordinate analysis classified the 357 genotypes into three well-differentiated genetic populations. Genotypes from the same region grouped into different clusters, while others from different regions fell into the same cluster. This indicates that differences in regions of origin may not be the main driver determining the genetic diversity in cowpea in Ethiopia. Therefore, differences in sources of origin, as currently distributed in Ethiopia, should not necessarily be used as indices of genetic diversity. Choice of parental lines should rather be based on a systematic assessment of genetic diversity in a specific population. The study also suggested 94 accesstions as core collection which retained 100% of the genetic diversity from the entire collection. This core set represents 26% of the entire collection pinpointing a wide distribution of the diversity within the ethiopian landraces. The outcome of this study provided new insights into the genetic diversity and population structure in Ethiopian cowpea genetic resources for designing effective collection and conservation strategies for efficient utilization in breeding.
Information on traits relationship, genetic variation and gains from selection for symbiotic and ... more Information on traits relationship, genetic variation and gains from selection for symbiotic and agronomic characters in chickpea (Cicer arietinum L.) are limited. An experiment was undertaken at two locations (Ginchi and Ambo) in Ethiopia in 2009/2010 to assess the relationship, genetic variation and genetic gain from selection for attributes of symbiotic and agronomic significance. The difference technique with genetically non-nodulating chickpea reference was employed to estimate the amount of symbiotic nitrogen fixation. Significant positive correlations were found between a number of symbiotic and agronomic traits. Grain yield was positively associated with fixed nitrogen assimilation efficiency (r = 0.39), shoot (r = 0.31), grain (r = 0.93), and above ground biomass nitrogen yields (r = 0.77) and NHI (r = 0.52). Grain yield was also positively influenced by agronomic characters including grain filling period (r = 0.38), pod (r = 0.57) and seed numbers (r = 0.59), shoot (r = 0....
Chickpea (Cicer arietinum L.) is one of the most important food legumes grown all over the world.... more Chickpea (Cicer arietinum L.) is one of the most important food legumes grown all over the world. In Ethiopia, chickpea is among the most important food legumes both in terms of area coverage and volume of production. The production of chickpea is important not only in terms of human and animal nutrition but also in terms of ecological sustainability through symbiotic nitrogen fixation. Despite the importance, productivity of chickpea is constrained at least in part by production problems related to the inherent low-yielding potential of the local cultivars, production without application of adequate inputs including fertilizers and post-harvest insect pest damage particularly adzuki bean beetle (Callosobruchus chinensis L.). Ethiopia is known as one of the centers of secondary diversity for chickpea. Genetic resources with proven performance for better symbiotic nitrogen fixation, phosphorus uptake and use efficiency and adzuki bean beetle resistance are limited for focused utiliza...
BackgroundSesame is an important oil crop widely cultivated in Africa and Asia continent. Charact... more BackgroundSesame is an important oil crop widely cultivated in Africa and Asia continent. Characterization of genetic diversity and population structure of sesame genotypes in these continents can be used to designing breeding methods. In the present study, 300 sesame genotypes comprising 209 local, and 75 exotic collection, and 16 released varieties provided from the Ethiopian Biodiversity Institute and research centers were used in the present study.ResultsThe panel was genotyped using two ultra-high-throughput diversity array technology (DArT) markers (silicoDArT and SNP). Both markers were used to identify the genetic diversity and population structure of sesame germplasm. A total of 6115 silicoDArT and 6474 SNP markers were reported, of which 5002 silicoDArT and 4638 SNP markers were screening with quality control parameters. The average polymorphic information content values of silicoDArT and SNP markers were 0.07 and 0.08, respectively. For further analysis, the allele freque...
Abstract: Storage insect pests cause significant losses of food legumes particularly in the Tropi... more Abstract: Storage insect pests cause significant losses of food legumes particularly in the Tropics and the Sub-tropics. The most important species of storage insect pests of food legumes include Callosobruchus chinensis, C. maculatus, C. analis, Acanthoscelides ...
Gemechu Keneni1,*, Mussa Jarso1, Tezera Wolabu2 and Getnet Dino1 1Holetta Agricultural Research C... more Gemechu Keneni1,*, Mussa Jarso1, Tezera Wolabu2 and Getnet Dino1 1Holetta Agricultural Research Center, PO Box 2003, Addis Ababa, Ethiopia; 2Kulumsa Agricultural Research Center, PO Box 489, Asella, Ethiopia; *Author for correspondence ... Received 26 August ...
Field experimental details are the same as those outlined in Paper 1. Data on chocolate spot (Bot... more Field experimental details are the same as those outlined in Paper 1. Data on chocolate spot (Botrytis fabae) in faba bean and Aschochyta blight (Mycosphaerella pinodes) in field pea were recorded based on a 1-9 scale and analyzed. The result showed highly significant differences among the treatments, between years and locations and their interaction effects in most of the cases. Mixed-cropping did not exclude the occurrence of both diseases, the incidences of which were relatively higher at Holetta than at Denbi. Chocolate spot at Denbi and Ascochyta blight in field pea at both locations also significantly differed between the systems. Faba bean varieties Mesay and NC 58 were more affected by chocolate spot under both systems. However, mixed production of the two crops favored incidence of chocolate spot in faba bean and disfavored Ascochyta blight maybe due to changes in the microenvironment associated with changes in the cropping systems. Field pea as an intercrop may reduce free...
Breeding of Abyssinian field pea (Pisum sativum var. Abyssinicum) genotypes effective forbiologic... more Breeding of Abyssinian field pea (Pisum sativum var. Abyssinicum) genotypes effective forbiological nitrogen fixation (BNF) has considerable economic and ecological significance. Anexperiment was conducted to study the magnitude of genetic diversity for attributes ofbiological nitrogen fixation. The experiment was carried out in 2007 in the greenhouse onVertisol and Nitisol soils at Addis Ababa University using a randomized complete block designwith three replications, where the Nitrogen difference technique with Yellow Dodolla, a varietyof Brassica carinata A Braun as a reference crop, was used to estimate the proportions of nitrogenderived from soil and atmosphere. Differences among the accessions for 14 traits studied weresignificant on both soil types. However, genotype by soil type interaction effects were significantonly for early vigor, number of nodules, nodule dry weight, foliage phosphorus content (%),phosphorus derived from fertilizer (%) and phosphorus uptake efficiency (%). This indicatedthat the two soils were distinctly different or the accessions responded differently to soil type forthese traits. Cluster analysis for average performances on the two soils grouped the accessionsinto four different classes, and Mahalanobis’s D 2 analyses showed significant genetic distancesbetween most of the clusters. Five accessions, namely MColl-7/07, MColl-8/07, TKColl-6/07,MCColl-4/07 and TKColl-3/07 were identified as best fixers of nitrogen under both Vertisol andNitisol soils with a fixation range of 41- 45 % and these accessions could be exploited in futurebreeding endeavors to develop BNF efficient genotypes. Additionally, there was no clearinterrelationship between the origins of accessions and the pattern of genetic diversity as therewere genotypes from the same source of origin fell into different clusters and vice versa.
A study was conducted to determine the optimum lime/CaCO<sub>3</sub> rate and incubat... more A study was conducted to determine the optimum lime/CaCO<sub>3</sub> rate and incubation period and exchangeable acidity equivalence for the amelioration of acidic nitisols collected from the central highlands of Ethiopia. A pot experiment was conducted at Holeta Agricultural Research Centre (HARC) in lath house using acidic soil samples collected from a depth of 0-20 cm from Bedi area, central high lands of Ethiopia. The treatments consisted of factorial combination of lime rates (0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 mg kg soil) and different incubation periods (7, 14, 21, 28, 35, 42 days). The treatments were arranged in RCBD with two replications. The result of the study showed that the soil pH consistently increased with the increase in lime application rates. There is no clear trend of incubation period effect on soil pH but higher pH was recorded after four weeks of incubation following lime application indicating that lime incubation period for o...
African Journal of Environmental Science and Technology, 2015
Many people in Africa depend on water from borehole, but purity of the drinking water from this s... more Many people in Africa depend on water from borehole, but purity of the drinking water from this source remains questionable. In a bid to ascertain the health risk local people are exposed to, this study analyses the physico-chemical characteristics of borehole water in Gassol Local Government Area (LGA), Nigeria. For this purpose, water samples were collected from the 12 administrative wards in the LGA. Two samples were collected from each ward, one in the rainy season (March) and another in the dry season (November), a total of 24 water samples in all. The water samples were analyzed for 18 different physical and chemical parameters to ascertain their comparability with the guideline levels recommended by the Standard Organization of Nigeria (SON) and World Health Organization (WHO). Results show that most parameters were within the guideline values in both seasons except for turbidity, pH, fluoride (F-), chlorine (Cl +), iron (Fe 2+), ammonia (NH 4 +) and manganese (Mn 2 +). Overall, all of the wards had at least one instance in which a parameter falls outside recommended guideline. A further analysis using the mean value test approach to assess level of contamination relative to guideline values showed that the upper bound value (US 95) of turbidity, iron, pH and chlorine are greater than their guideline values. This indicates that these are the parameters for which the most urgent action is needed. The high concentration of iron and turbidity outside the prescribed limits in the rainy season suggests that water managers need pay more attention to borehole water quality in the rainy season. There is need for further research across the region to better understand the quality and the contaminants (natural and anthropogenic) of borehole water so as to be able to proffer appropriate remediation strategy.
Finger millet (Eleusine coracana L.) is one of the important indigenous crops of Africa. The prod... more Finger millet (Eleusine coracana L.) is one of the important indigenous crops of Africa. The productivity of the crop, however, is very low owing to several factors including the inherent low-yielding potential of the cultivars. Information on genetic diversity among the available germplasm collections is very useful for breeding programs utilizing the materials as germplasm source. An experiment was conducted at Arsi Negele and Bako, Ethiopia, in 2000 main season to study the extent of genetic variability present among sixty-four germplasm accessions collected from the Eastern and Southern Africa and maintained at the Institute of Biodiversity Conservation, Ethiopia. The accessions were planted in three replications at both locations using a randomized complete block design. Data were recorded on eleven morpho-agronomic characters. Analysis of variance at both locations showed that the mean squares due to genotype and genotype by location interaction were significant (P < 0.05) in almost all the cases. Broad-sense heritability values at each location and combined over locations were higher (> 80%) for most of the characters, indicating the existence of a wealth of genetic variability among the population for most of the morpho-agronomic traits. Cluster analysis grouped the accessions into four clusters of different sizes. It appears that geographical origin has no or little effect in determining the pattern of genetic diversity observed among the accessions. The greatest variability among accessions was observed for characters such as biomass, ear weight and grain weight, which highly dictated the differentiation of accessions into clusters. Genetic distances between cluster IV and all other clusters were significant indicating that crosses between selection from members of cluster IV with the rest of the clusters may provide desirable recombinant in breeding efforts. Parental selection should also be based on the existence of optimum level of the desired traits.
This study was undertaken to evaluate the extent and pattern of genetic diversity for immature po... more This study was undertaken to evaluate the extent and pattern of genetic diversity for immature pod traits in Ethiopia cowpea landrace collections. Eighty one landraces and improved cultivars were tested in a 9 x 9 simple lattice design. Analysis of variance revealed highly significant (P<0.01) or significant (p<0.05) differences among the genotypes for all traits. The first four principal components were able to explain 81% of variation for quantitative traits and 76% for qualitative traits. The genotypes were grouped into three distinct clusters, the first, second and third clusters with 60, 15 and 25% of the genotypes in that order. The landraces were distributed all over the clusters while the improved cultivars were absent in the second cluster. Shannon-Weaver diversity indices also showed existence of adequate genetic variability among the genotypes for qualitative traits. Shannon-Weaver diversity indices ranged from the lowest of 0.50 for pod curvature to the highest of 0.99 for pod shape. The study clearly showed that, even if the genotypes were classified into a few cluster, there was adequate divergence among the clusters showing existence of considerable genetic variability for immature pod traits for exploitation in future breeding for better green pod yield and quality in cowpea.
Fourteen field pea genotypes were evaluated at 16 environments in Ethiopia during 2007 and/or 200... more Fourteen field pea genotypes were evaluated at 16 environments in Ethiopia during 2007 and/or 2008 main cropping seasons. The objective of the study was to determine the magnitude of genotype × environment interaction and performance stability in the field pea genotypes. The study was conducted using a randomized complete block design with 4 replications. Genotype × environment interaction and yield stability were estimated using the additive main effects and multiplicative interaction and site regression genotype plus genotype × environment interaction biplot. Pooled analysis of variance for grain yield showed significant (p<0.01) differences among the genotypes, environments and the genotype × environment interaction effects. This indicated that the genotypes differentially responded to the changes in the test environments or the test environments differentially discriminated the genotypes or both. Environment accounted for 74.3% of the total yield variation, genotype for 4.2% and genotype × environment for 16.4%, indicating the need for spatial and temporal replication of variety trials. The first five bilinear terms of AMMI were found to be significant. The first two multiplicative component terms sum of squares, with their cumulative degrees of freedom of 52, explained 69.1% of the interaction sum of squares. No single variety showed a superior performance in all the environments but genotype EH02-036-2, followed by Coll.026/01-4, demonstrated top ranking at five of the sixteen environments. The application of AMMI and GGE biplots facilitated the visual comparison and identification of superior genotypes, thereby supporting decisions on variety selection and recommendation in different environments.
Ethiopia is considered an important center of secondary diversity for both faba bean (Vicia faba ... more Ethiopia is considered an important center of secondary diversity for both faba bean (Vicia faba L.) and field pea (Pisum sativum L.). However, areas of eco-geographic distribution and the microcenter of genetic diversity are not well known. Two separate trials consisting of 160 faba bean and 148 field pea accessions were conducted at Holetta and Kulumsa in 2001. Simple and alpha-lattice designs with 2 replications were used for faba bean and field pea, respectively. Cluster analysis grouped faba bean accessions into eight and field pea into five different classes. Mahalanobis's D 2 analyses showed significant genetic distances between most of the clusters in both crops. Accessions from the northern parts of the country showed tendencies of being grouped together, indicating that their genetic background may be related. Accessions from the southern parts of the country were distributed over most of the clusters showing more genetic diversity compared to those from the northern parts. This indicates that the distribution of genetic diversity among accessions is not uniform across different eco-geographical regions in Ethiopia and the microcenter of genetic diversity for both crops may be located in the southern part of the country. The existence of more genetic diversity in one region compared to the other could be due to differences in the level of variability among the original introductions to different regions, the nature and degree of both human and natural selections after introduction, and effects of ecological and agricultural conditions as major forces of evolution. Future collection, conservation and utilization programs should focus on the southern part to safeguard and exploit the tremendous genetic diversity. However, a comprehensive study involving both morpho-agronomic traits and molecular markers would be needed for a more comprehensive conclusion.
Plant breeding is one way to confront the challenge of bridging the widening gap between the dema... more Plant breeding is one way to confront the challenge of bridging the widening gap between the demand and supply of food. Despite the importance, however, plant breeding has its own negative side effects. The replacement of landraces with a few genetically uniform varieties depletes genetic diversity and provides ideal conditions for diseases and insect pests that called genetic vulnerability. The increasingly growing human population and the subsequently rising demands for more food, on the one hand, and the success of such efforts like the "Green Revolution" from adoption of genetically uniform varieties in many parts of the world, on the other, are the main driving force towards this narrow genetic base. It is, therefore, important to understand the phenomena and plan to minimize the risks from genetic vulnerability. Under marginal conditions where resource-poor farmers dominate, the current plant breeding strategies, variety release, registration and certification procedures leading to genetic uniformity should be reconsidered and some level of genetic diversity should deliberately be maintained in variety development programs. Genetic diversity can be introduced at different levels and in different ways which may include intra-varietal, inter-varietal, inter-parental and inter-specific diversities. Breeding for specific adaptation instead of wide adaptation, systematic spatial and temporal gene deployment, use of inter-specific varietal mixtures and integration of horizontal and vertical resistances have been suggested as solutions.
Crop production plays a significant role in the Ethiopian economy. The sub-sector's output has, h... more Crop production plays a significant role in the Ethiopian economy. The sub-sector's output has, however, been very low partially due to the biophysical challenges constraining productivity in smallholder farms and inadequate technological interventions. Genetic modification of crops to improve productivity is preferred to the continual manipulation of the growing environment because of cost particularly to the large majority of resource-poor farmers who cannot afford for production inputs. Consideration of varietal selection vis-à-vis actual target production environment is vital to maximizing gains from breeding efforts. The tradition across most of the breeding programs in Ethiopia is to develop varieties under optimum management despite the fact that marginal management characterizes the ultimate target production environments. Whether selection under optimum management is likely to result in better productivity gain than under the actual target production environments is a crucial issue in varietal development. This paper discusses the logical framework for breeding success and the conventional approach to varietal selection and its challenges in Ethiopia. Based on the analyses, the paper proposes that the wheel of the current variety development schemes should be redirected and made more objective and focused towards better serving the major target beneficiaries, i.e. the resource-poor farmers.
... AGRIS 2011 - FAO of the United Nations. Related AGRIS Results: -, Assessment of losses in yie... more ... AGRIS 2011 - FAO of the United Nations. Related AGRIS Results: -, Assessment of losses in yield and yield components of maize varieties due to grey leaf spot by Dagene Wegary; Demissew Kitaw; Girma Demissie (2004) in English. ...
International Journal of Sustainable Agricultural Research
Chickpea is one of the most cultivated grain legumes in Ethiopia for grain production and amelior... more Chickpea is one of the most cultivated grain legumes in Ethiopia for grain production and amelioration of soil fertility with less attention in research on N-fixation. Therefore, this study was conducted to estimate the magnitude of heterosis for nitrogen fixation and yield and yield associated traits in chickpea (Cicer arietinum L.). Six F1 crosses obtained from crossing of four parents (two nodulated and non-nodulated) in a half diallel fashion were evaluated in 2014/15 season in lath house using Randomized Complete Block Design (RCBD) with two replications at Debre Zeit Agricultural Research Center. Significant (P<0.05) differences were exhibited among entries for all traits studied. Considering all traits, relative to the mid parent (MPH), better parent (BPH) and standard heterosis (SH) in percent ranged from 0.009 to 59.8, 0.009 to39.9 and 0.009 to58.8, respectively. The highest degrees of MPH were noted for nodule dry weight and of BPH and SH were noted for number of pods per plant, while the lowest was observed for grain yield (0.009). The hybrid obtained from nodulated parents (ICC5003 x ICC19180) showed high heterosis for number of nodule on the basis of MPH and BPH, while ICC4918x ICC19181 exhibited low heterotic effect which exhibited positive and significant MPH for nitrogen fixed in grain, BPH for seed filling duration and SH for days to 50% flowering, days to 90% maturity and shoot dry weight at maturity traits. 1. INTRODUCTION Chickpea (Cicer arietinum L.) is one of the most important food legume crops widely produced-globally on over 12 million hectares of land from which 10.9 million tons of grain is produced every year (FAOSTAT, 2012). It ranks second in area coverage (15.3% of the total area allotted to food legumes) and third in volume of production (14.6%) after common beans (Phaseolus vulgaris L.) and field peas (Pisum sativum L.) (Knights et al., 2007). In Ethiopia chickpea production ranks third in area and production among legumes next to faba bean and haricot bean (CSA, 2014/15). Out of 1.6 million hectares allocated for pulse , chickpea covered 239,755 hectares of land from
Eleven faba bean (Vicia faba L.) varieties released between 1977 and 2007, and two promising geno... more Eleven faba bean (Vicia faba L.) varieties released between 1977 and 2007, and two promising genotypes, were evaluated to estimate the genetic progresses made in 33 years of faba bean breeding in Ethiopia. The study was conducted at eight environments during 2007 and 2009 cropping seasons in a randomized complete block design with four replications. Records taken on grain yield, seed size and chocolate spot (Botrytis fabae) severity were subjected to statistical analysis. Combined analysis of variance revealed highly significant differences among the genotypes and the test environments for all traits, the G × E interaction effects being significant for grain yield and seed size. Regression of mean performance at all environments on year of varietal release showed positive relationship for grain yield (r = 0.48) and seed size (r = 0.80**) but negative for chocolate spot (r = -0.60*). The annual rates of genetic progresses were 8.74 kg ha -1 , 8.07 g 1000 seeds -1 and -0.27% for grain...
Cowpea [Vigna unguiculata (L.) Walp] is one of the important climate-resilient legume crops for f... more Cowpea [Vigna unguiculata (L.) Walp] is one of the important climate-resilient legume crops for food and nutrition security in sub-Saharan Africa. Ethiopia is believed to harbor high cowpea genetic diversity, but this has not yet been efficiently characterized and exploited in breeding. The objective of this study was to evaluate the extent and pattern of genetic diversity in 357 cowpea accestions comprising landraces (87%), breeding lines (11%) and released varieties (2%), using single nucleotide polymorphism markers. The overall gene diversity and heterozygosity were 0.28 and 0.12, respectively. The genetic diversity indices indicated substantial diversity in Ethiopian cowpea landraces. Analysis of molecular variance showed that most of the variation was within in the population (46%) and 44% between individuals, with only 10% of the variation being among populations. Model-based ancestry analysis, the phylogenetic tree, discriminant analysis of principal components and principal coordinate analysis classified the 357 genotypes into three well-differentiated genetic populations. Genotypes from the same region grouped into different clusters, while others from different regions fell into the same cluster. This indicates that differences in regions of origin may not be the main driver determining the genetic diversity in cowpea in Ethiopia. Therefore, differences in sources of origin, as currently distributed in Ethiopia, should not necessarily be used as indices of genetic diversity. Choice of parental lines should rather be based on a systematic assessment of genetic diversity in a specific population. The study also suggested 94 accesstions as core collection which retained 100% of the genetic diversity from the entire collection. This core set represents 26% of the entire collection pinpointing a wide distribution of the diversity within the ethiopian landraces. The outcome of this study provided new insights into the genetic diversity and population structure in Ethiopian cowpea genetic resources for designing effective collection and conservation strategies for efficient utilization in breeding.
Information on traits relationship, genetic variation and gains from selection for symbiotic and ... more Information on traits relationship, genetic variation and gains from selection for symbiotic and agronomic characters in chickpea (Cicer arietinum L.) are limited. An experiment was undertaken at two locations (Ginchi and Ambo) in Ethiopia in 2009/2010 to assess the relationship, genetic variation and genetic gain from selection for attributes of symbiotic and agronomic significance. The difference technique with genetically non-nodulating chickpea reference was employed to estimate the amount of symbiotic nitrogen fixation. Significant positive correlations were found between a number of symbiotic and agronomic traits. Grain yield was positively associated with fixed nitrogen assimilation efficiency (r = 0.39), shoot (r = 0.31), grain (r = 0.93), and above ground biomass nitrogen yields (r = 0.77) and NHI (r = 0.52). Grain yield was also positively influenced by agronomic characters including grain filling period (r = 0.38), pod (r = 0.57) and seed numbers (r = 0.59), shoot (r = 0....
Chickpea (Cicer arietinum L.) is one of the most important food legumes grown all over the world.... more Chickpea (Cicer arietinum L.) is one of the most important food legumes grown all over the world. In Ethiopia, chickpea is among the most important food legumes both in terms of area coverage and volume of production. The production of chickpea is important not only in terms of human and animal nutrition but also in terms of ecological sustainability through symbiotic nitrogen fixation. Despite the importance, productivity of chickpea is constrained at least in part by production problems related to the inherent low-yielding potential of the local cultivars, production without application of adequate inputs including fertilizers and post-harvest insect pest damage particularly adzuki bean beetle (Callosobruchus chinensis L.). Ethiopia is known as one of the centers of secondary diversity for chickpea. Genetic resources with proven performance for better symbiotic nitrogen fixation, phosphorus uptake and use efficiency and adzuki bean beetle resistance are limited for focused utiliza...
BackgroundSesame is an important oil crop widely cultivated in Africa and Asia continent. Charact... more BackgroundSesame is an important oil crop widely cultivated in Africa and Asia continent. Characterization of genetic diversity and population structure of sesame genotypes in these continents can be used to designing breeding methods. In the present study, 300 sesame genotypes comprising 209 local, and 75 exotic collection, and 16 released varieties provided from the Ethiopian Biodiversity Institute and research centers were used in the present study.ResultsThe panel was genotyped using two ultra-high-throughput diversity array technology (DArT) markers (silicoDArT and SNP). Both markers were used to identify the genetic diversity and population structure of sesame germplasm. A total of 6115 silicoDArT and 6474 SNP markers were reported, of which 5002 silicoDArT and 4638 SNP markers were screening with quality control parameters. The average polymorphic information content values of silicoDArT and SNP markers were 0.07 and 0.08, respectively. For further analysis, the allele freque...
Abstract: Storage insect pests cause significant losses of food legumes particularly in the Tropi... more Abstract: Storage insect pests cause significant losses of food legumes particularly in the Tropics and the Sub-tropics. The most important species of storage insect pests of food legumes include Callosobruchus chinensis, C. maculatus, C. analis, Acanthoscelides ...
Gemechu Keneni1,*, Mussa Jarso1, Tezera Wolabu2 and Getnet Dino1 1Holetta Agricultural Research C... more Gemechu Keneni1,*, Mussa Jarso1, Tezera Wolabu2 and Getnet Dino1 1Holetta Agricultural Research Center, PO Box 2003, Addis Ababa, Ethiopia; 2Kulumsa Agricultural Research Center, PO Box 489, Asella, Ethiopia; *Author for correspondence ... Received 26 August ...
Waterlogging is a major constraint of faba bean (Vicia faba L.) production in the highland vertis... more Waterlogging is a major constraint of faba bean (Vicia faba L.) production in the highland vertisols of Ethiopia. Genotypes are currently evaluated under both the drained conditions of Broad Bed and Furrow (BBF) and the undrained flatbeds. The objective of this research was to determine if selection of genotypes under BBF is efficient for identification of genotypes for the flatbed conditions. Yields under the flatbed conditions were lower by 20-50% (38% on average) than yields under the BBF. Genetic variation, heritability and predicted genetic gains for grain yield due to direct selection were also lower under the flatbeds than they are under the BBF. There were good levels of genetic correlation (r = 0.20-0.75 or 0.45 on average) between yield performances under BBF and flatbeds, indicating that selection under BBF may identify good genotypes for flatbeds and vice versa. There was also high association (r = 0.91) between relative yield reduction under flatbeds and the ratio of the predicted genetic gains from indirect selection under BBF to the predicted genetic gains from direct selection under flat beds. This indicates that indirect selection under BBF may be useful to identify better genotypes for flatbed conditions, but the relative efficiency of indirect selection was lower than direct selection under flatbeds themselves.
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Papers by Gemechu Wakeyo