129 research outputs found

    Photosynthetic Responses of Seedlings of two Indigenous Plants inside Exotic Tree Plantations and adjacent Natural Forest in Munessa–Shashemene Forest, SouthernEthiopia

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    The potential role of exotic tree plantations in facilitating successional processes on degraded areas was evaluated in southern Ethiopia, Munessa-Shashemene forest, by examining photosynthetic responses of Bersamaabyssinica Fres. and Croton macrostachyusDel. seedlings naturally grown inside plantations of Eucalyptussaligna and Pinuspatula and adjacent natural forest. Photosynthetic responses of the seedlings were recorded using modulated photosynthesis yield analyzer, Mini-PAM. Analysis of fluorescence parameters in the leaves showed no significant differences in the level of dark-adapted and light-adapted fluorescence yield (Fv/Fm and Ă„F/Fm,, respectively) among seedlings grown inside plantations and adjacent natural forest indicating similar photosynthetic performance. The light response curves of electron transport rate (ETR), light-adapted fluorescence yield (Ă„F/Fm,) and non-photochemical quenching (NPQ)showed similar light saturation behavior among the seedlings grown inside plantations and natural forest and suggested a shade-adapted behavior of Bersamaabyssinica as compared to Croton macrostachyus. The results suggest the role of exotic tree plantationsin facilitating restoration processes on degraded areas by improving light conditions for photosynthesis.Keywords: Chlorophyll fluorescence, Light response curves, PS II, Restoration, Ethiopia

    The concept of benefit sharing in the context of the eastern Nile Basin

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    This study attempted to predict the likely impacts of a dam reservoir and flow regulation on riparian plant composition and diversity. The study was conducted around the Koga dam in the upper part of the Blue Nile basin in the northwestern part of Ethiopia. Floristic composition and diversity in the riverine and adjacent sites of the river was studied. The presence of plant species that would be affected by the storage of the Koga River water and the modification of the downstream river flow regime were assessed. A total of 87 plots (3.48 ha) were laid, of which 57 (2.28 ha) were located in the upstream area, 17 (0.68 ha) in the vicinity of the reservoir, and 13 (0.52 ha) in the downstream area. A total of 71 species were identified, of which 36.7 % were trees, 26.8 % shrubs, 18.3 % were herbs, and 4.2 % climbers. About 59 species of vascular plants, belonging to 39 families and 53 genera, were recorded upstream of the dam. 17 species comprising 15 families and 17 genera were recorded in the area that will be flooded by the reservoir and 21 species comprising 15 families and 18 genera were recorded in the riparian zone downstream of the dam. Comparison of species indicates that though there is no significant difference between the three sites in terms of species density (p = 0.345). The downstream region has more diverse and evenly distributed species compared to the upstream and reservoir areas. There was no significant difference in terms of species density and diversity in the adjacent and riverine parts of the upstream and downstream areas. Most of the species in the area downstream of the dam including Dodonea angustifolia, Ensete ventricosum, Syzygium guineense, Accacia spp., Combretum adengonium, and Combretum molle, which were found exclusively in the riverine part, are species that are normally found inhabiting riverine areas. This indicates that the majority of the downstream vegetation prefers moisture rich substratum. Flow history was examined to analyze the likelihood of disturbance in scenarios with and without flow regulation. The hydrological analysis shows that the dam may lead to reductions in maximum daily discharges and flood frequency. Reductions in flood peaks and over-bank flows could result in changes in species composition and diversity of plants growing in water or water rich substratum below the dam

    Delivering new sorghum and finger millet innovations for food security and improving livelihoods in Eastern Africa

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    ILRI works with partners worldwide to help poor people keep their farm animals alive and productive, increase and sustain their livestock and farm productivity, and find profitable markets for their animal products. ILRI’s headquarters are in Nairobi, Kenya; we have a principal campus in Addis Ababa, Ethiopia, and 14 offices in other regions of Africa and Asia. ILRI is part of the Consultative Group on International Agricultural Research (www.cgiar.org), which works to reduce hunger, poverty and environmental degradation in developing countries by generating and sharing relevant agricultural knowledge, technologies and policies

    Additive Main Effects and Multiplicative Interactions (AMMI) and genotype by environment interaction (GGE) biplot analyses aid selection of high yielding and adapted finger millet varieties

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    Background and justification: Lack of stable high yielding cultivars is one of the major bottlenecks for production and productivity of finger millets in Ethiopia. Identification of adaptable, stable and high yielding genotypes under varying environmental conditions prior to release as a cultivar is the first and foremost steps for plant breedingr and this has direct bearing on the adoption of the variety, its productivity and total production of the crop.Objective: The major objectives of the present study were to (i) assess the stability and yield performance of advanced finger millet genotypes  evaluated in multiple environments, and (ii) identify stable high yieldingcandidate cultivar (s) for possible release using different statistical tools.Material and methods: A total of 30 advanced finger millet genotypes were evaluated against two standard checks (Gute and Taddese) across four locations (Arsi Negele, Assosa, Bako and Gute) in 2012 and 2013 main cropping seasons. The trial was arranged in a randomized complete block design (RCBD) replicated three times.Summary result and application of the study: Additive Main effect and Multiplicative Interaction (AMMI), Genotype and Genotype by Environment interaction (GGE) biplot analysis and, Eberhart and Russellmodel revealed that Acc. 203544 is stable high yielding (3.16 ton ha-1) with a yield advantage of 13.7% over the best standard check, Gute (2.78 ton ha-1), and thus should be recommended for possible release with wider environmental adaptability. Acc. 242111 (3.08 ton ha-1), Acc. BKFM0051 (3.07 ton ha-1) and Acc.229738 (2.99 ton ha-1) were also high yielding, but showed narrow stability and thus should be recommended for verification and possible release for specific environments.Key words/phrases: Additive main effect and multiplicative interaction (AMMI), Finger millet (Eleusine coracana subsp. coracana), Genotype by Environment Interaction (GEI

    Evaluation of bio-physiological and yield responses of stay green QTL introgression sorghum lines to post-flowering drought stress

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    Drought is the most drastic abiotic stress that limits crop production in sub-Sahara Africa. Sorghum ( Sorghum bicolor (L.) Moench) is among the most climate resilient cereals of the future due to its tolerance to drought and heat. Thus, identification of tolerant genotypes and plant characteristics that contribute to drought adaptation is timely. The objective of this study was to evaluate the response of 12 genotypes, including seven Stay-green (Stg) QTL introgression sorghum lines and their two donor; and three recurrent parents, to induced post-flowering drought stress. The recurrent parents were varieties released for drought prone lowlands of the country, and the donor parents were lines known to have stay-green properties. The study was conducted at Werer, in the Great Rift-valley of Ethiopia, during the off-season of 2014 under well-watered and water limited conditions. Significant differences (P<0.05) were observed among genotypes under water deficit regimes, for all measured physiological, biochemical (proline content), yield and yield related traits. Three Stg QTL introgression lines showed better tolerance to drought than their recurrent parents, as reflected by yield and maintenance of green leaf area. Three Stg QTL introgression lines, Teshale/E36-1, Gambella/B35-5 and Meko/B35-12, gave the highest grain yield under post-flowering drought stress, and B35 and Teshale/B35 gave the poorest yield under similar conditions. Therefore, these improved lines bear potential for use as alternatives in breeding programmes and for possible release in parts of the country where post-flowering drought stress is frequent. Proline content, weight of hundred seeds (HSW) and CO2 assimilation are effective screening tools for Stg property due to their high correlation with other parameters.La s\ue8cheresse est le stress abiotique le plus drastique qui limite la production agricole en Afrique Sub-saharienne. Le sorgho ( Sorghum bicolor (L.) Moench) est parmi les c\ue9r\ue9ales les plus r\ue9silientes au climat pour le futur d\ufb \ue0 sa tol\ue9rance \ue0 la s\ue9cheresse et \ue0 la chaleur. Donc, l\u2019identification des g\ue9notypes tol\ue9rants et les caract\ue9ristiques des plants qui contribuent \ue0 l\u2019adaptation \ue0 la s\ue9cheresse est opportune. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer la r\ue9ponse de 12 g\ue9notypes, comportant sept lign\ue9es de sorgho conf\ue9rant l\u2019introgression des QTL des attributs verts (Stg), leurs deux donneurs\ua0; et les trois parents r\ue9currents, au stress de la s\ue9cheresse post floraison induite. Les parents r\ue9currents ont \ue9t\ue9 les vari\ue9t\ue9s lib\ue9r\ue9es sensibles \ue0 la s\ue9cheresse dans les plaines du pays, et les donneurs ont \ue9t\ue9 les lign\ue9es connues pour leurs propri\ue9t\ue9s relatives aux attributs verts. L\u2019\ue9tude a \ue9t\ue9 conduite \ue0 Werer, dans la grande vall\ue9e du Rift d\u2019Ethiopie, pendant la contre saison de 2014 dans des conditions d\u2019irrigation abondante et d\u2019irrigation limit\ue9e. De diff\ue9rences significatives (P<0.05) ont \ue9t\ue9 observ\ue9es entre les g\ue9notypes sous des r\ue9gimes de d\ue9ficit hydriques, pour tous les traits physiologiques, biochimiques (teneur en proline), le rendement et les composantes de rendement. Trois lign\ue9es d\u2019introgression de Stg QTL ont montr\ue9 de meilleure tol\ue9rance \ue0 la s\ue9cheresse que leurs parents r\ue9currents, comme refl\ue9t\ue9 par le rendement et la maintenance de la surface verte de la feuille. Trois lign\ue9es d\u2019introgression de Stg QTL, Teshale/E36-1, Gambella/B35-5 et Meko/B35-12, ont donn\ue9 le plus haut rendement sous le stress de s\ue9cheresse de post floraison, et B35 et Teshale/B35 ont donn\ue9 le plus faible rendement dans des conditions similaires. En cons\ue9quence, ces lign\ue9es am\ue9lior\ue9es d\ue9tiennent tout le potentiel pour leur usage comme alternatives dans des programmes d\u2019am\ue9lioration g\ue9n\ue9tiques et pour une lib\ue9ration possible dans les r\ue9gions du pays o\uf9 le stress de la s\ue9cheresse post floraison est fr\ue9quent. La teneur en proline, le poids de 100 graines (HSW) et l\u2019assimilation du CO2 sont des outils effectifs de criblage pour la propri\ue9t\ue9 de Stg due \ue0 leur forte corr\ue9lation avec les autres param\ue8tres

    Shock and patient preimplantation type D personality are associated with poor health status in patients with implantable cardioverter-defibrillator

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    Background: Implantable cardioverter-defibrillator (ICD) shock is a critical event to patients associated with well-being after implantation, although other factors may play an equally important role. We compared the association of shock and the patient's preimplantation personality with health status, using a prospective study design. Methods and Results: Consecutively implanted ICD patients (n=383; 79% men) completed the Type D Scale at baseline and the Short-Form Health Survey 36 (SF-36) at baseline and 3, 6, and 12 months. Of all patients, 23.5% had a Type D personality and 13.8% received a shock during follow-up. Shocked patients reported significantly poorer health status, as did Type D patients. Health status patterns were poorest in patients with combined Type D personality and shock during follow-up. Shock during follow-up was a significant independent associate of poorer health status for 4 of 8 subscales of the SF-36 and the Mental Component Summary (all P<.05), with shocked patients scoring between 2.60 to 13.30 points lower than nonshocked patients. Type D personality was an independent associate of poor postimplantation health status for 6 of 8 of the SF-36 subscales and the Mental Component Summary, with Type D patients scoring between 2.12 to 8.02 points lower, adjusting for demographic and clinical characteristics. Conclusions: ICD shock and the patient's preimplantation personality disposition were equally important associates of health status 12 months after implantation. Identification of the patient's personality profile before ICD implantation may help identify subsets of patients who may need additional care, for example, with a psychosocial component

    Inheritance and Association of Quantitative Traits in Finger Millet (Eleusine coracana Subsp. Coracana) Landraces Collected from Eastern and South Eastern Africa

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    One hundred forty four finger millet landraces were collected from different regions of Ethiopia and some introduced from Eastern and south Eastern African (Kenya, Eritrea, Zambia and Zimbabwe) were planted with six improved varieties in RCBD design at Gute and Arsi Negele during 2011 cropping season to assess variability, heritability, genetic advance and association of quantitative traits. The analysis of variance indicated that the mean square due to location and genotype were highly significant (P#0.01) for all quantitative traits except ear weight for the latter case. Phenotypic coefficient of variation was higher than the corresponding genotypic and genotype by environment coefficient of variations for all traits. This implies, beside the genetic factors, environmental factors have high contributions for the variations observed. The higher heritability coupled with higher genetic advance noted for ear weight (71.14%), lodging index (53.49), finger length (41.94%), thousand grain weights (28.88) and grain yield per plant (26.34) indicated that the ease of phenotype based selection for the improvement of those traits. About 68.4% of the total traits association showed positive correlation. As obtained from path coefficient analysis, the higher and positive direct effect of productive tiller per plant (0.356) and thousand grain weight (0.285) and the positive direct effect of finger length, finger number, ear weight, number of grain per spikelet and culm diameter on grain yield indicated that any genetic improvement on those traits has positive contribution to improve productivity of finger millet

    Study of growth and physiological characters in stay-green QTL introgression Sorghum bicolor (L.) lines under post-flowering drought stress

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    This experiment was carried out to evaluate the growth, physiological and yield traits of stay-green (Stg) QTL introgression sorghum lines, which were developed by the Ethiopian Institute of Agricultural Research in collaboration with ICRISAT between 2006 and 2008, under induced post-flowering drought stress. It involved a total of 12 genotypes including seven Stg QTL introgression lines, two Stg donor parents and three senescent recurrent parents. It was organized in a split plot design with three replications under well-watered and induced drought stress growing conditions at Melka Werer, Ethiopia during the post-rainy season of 2014. Analysis of variance revealed that the effect of moisture regimes on all measured traits was significant (P > 0.05). Differences among the genotypes and genotypeby- water regime interaction were also significant (P > 0.05) for all the traits considered. Postflowering drought stress was observed to significantly reduce most of the growth, physiological and yield related traits. The Stg introgression lines Meko/B35-selection 120, Teshale/B35-selection 2 and Teshale/E36-1 showed better drought stress tolerance properties than the rest of the genotypes based on the measured growth and physiological traits. These introgression lines also showed better grain yield than their recurrent parents under post-flowering drought stress and can be used as new versions of the existing varieties (served as recurrent parents) and for future breeding programs. Furthermore, leaf chlorophyll content, assimilation rate, transpiration rate, water use efficiency, root length and root dry weight were found to have strong correlation and can be used to screen genotypes for post-flowering drought tolerance

    Genetic diversity and association mapping of Ethiopian and exotic finger millet accessions

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    Combining morphological and molecular data to identify genetic variation and marker–trait association is one of the most important prerequisites for genomics-assisted selection in crop improvement. To this end, a total of 138 finger millet (Eleusine coracana subsp. coracana) accessions including five improved varieties were evaluated to assess the genetic variation and population structure and undertake association mapping. These accessions were basically collected from Ethiopia (96), Eritrea (8), Kenya (7), Zambia (9) and Zimbabwe (13). Finger millet accessions were evaluated in the field for 10 important agronomic traits and also characterised using a set of 20 microsatellite markers. Mean polymorphism information content of 0.61 was observed from a total of 222 alleles with an average of 11.1 alleles per microsatellite locus. About 61% of alleles detected were rare (<5%) and specific allele amplification was observed in 34 accessions. Both weighted neighbour-joining based clustering using molecular data and hierarchical clustering using phenotypic trait data grouped the 138 accessions into four major clusters that were not entirely based on their geographical origins. Genome-wide association studies depicted 16 significant (P < 0.01) associations between 13 microsatellite markers and six agronomic traits. Our results reveal a unique abundance of rare alleles in finger millet and highlight the need for more careful selection of genome-wide association studies in the future in order to capture the contribution of rare alleles to important agronomic traits
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