211 research outputs found

    In vivo evaluation of wheat (Triticum aestivum L.) cultivars for moisture stress

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    In Ethiopia, wheat productivity is constrained by water stress especially at germination and seedling stage. The objective of this research was to determine the effect of moisture stress on bread wheat (Triticum aestivum) cultivars. Four wheat cultivars (Dandaa, Kubsa, Huluka and Local) were treated with six levels of water stress (0, 50, 100, 150, 200 and 250 g L-1) using PEG-6000. The experiment was arranged factorally in completely randomized design with three replications. Data on germination and growth indices were collected and analyzed using one way ANOVA. The result revealed that highest germination percentage (99.7%), germination rate (14.6 plants day-1) and seedling vigor index (9.67) were obtained from the local cultivar. Progressive increase in water stress had also significantly reduced germination indices. There was no significant difference among the cultivars in producing taller root and shoot length. The local cultivar had significantly produced highest root number (4.3 plant-1), shoot fresh weight (0.214 g), seedling fresh (0.314 g) and dry weight (0.097 g). Even though, all the growth parameters of wheat cultivars showed a diminishing trend with increasing the level of PEG-6000 induced water stress, a highly significant decrease in the parameters were observed starting from 150 g L-1 PEG concentration. Higher shoot length inhibition was observed for Dandaa cultivar followed by Huluka. Hulukas root growth was more inhibited than Dandaa. According to the growth and germination indices results, the local cultivar is the drought tolerant wheat cultivar. DOI: http://dx.doi.org/10.3329/ijarit.v4i2.22651 Int. J. Agril. Res. Innov. & Tech. 4 (2): 55-60, December, 201

    Nile tilapia (\u3ci\u3eOreochromis niloticus\u3c/i\u3e) fried in recycled palm oil: implications for nutrition and health

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    Fish constitutes a occasional food for the Sidama people of Hawassa, the capital city of Ethiopia’s Sidama Region and the site of a large endorheic lake. Freshly-caught fish, especially Nile tilapia or koroso in Local name, are typically fried prior to consumption. Despite the sensory qualities, fried foods are not always advisable due to the impact of frying on the nutritional quality of food. This study was designed to assess the nutritional quality of Nile tilapia that had been fried in the same palm oil over six consecutive frying cycles. The raw fish were purchased from the Lake Hawassa fish market and fried at Hawassa University by simulating local preparation methods. A gas chromatography- mass spectrophotometer (GCMS) was used for the fatty acid profile analysis and a total of 22 fatty acids were elucidated. The nutritional quality indices of fatty acids was determined by calculating the recommended formula and JMP pro 13 was used for statistical analysis. The study results revealed that the tilapia fried in the oldest, most used oil, cycles 3–6, contained high amounts of saturated and trans fatty acids, as well as high atherogenic and thrombogenic indices; however, it was also lower in essential and cis fatty acids, the hypocholesterolemic/hypercholesterolemic ratio, the per-oxidizability index, and the nutritive value index. Conversely, fish prepared earlier (cycles 1–3) with fresher oil were higher in essential fatty acids and cis fatty acids, while the hypocholesterolemic/hypercholesterolemic ratio, the per-oxidizability index, and the nutritive value index were also high. Fish fried in an earlier cycle were also low in saturated and trans-fatty acids, with a lower atherogenic index, and thrombogenic index. Therefore, it can be concluded that repeatedly using the same frying oil to prepare Nile tilapia contributed to the loss of nutritional value. Results suggest that palm oil should be limited to no more than three frying cycles to maximize nutritional intake in of fish consumption

    A maize landrace that emits defense volatiles in response to herbivore eggs possesses a strongly inducible terpene synthase gene.

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    Maize (Zea mays) emits volatile terpenes in response to insect feeding and egg deposition to defend itself against harmful pests. However, maize cultivars differ strongly in their ability to produce the defense signal. To further understand the agroecological role and underlying genetic mechanisms for variation in terpene emission among maize cultivars, we studied the production of an important signaling component (E)-caryophyllene in a South American maize landrace Braz1006 possessing stemborer Chilo partellus egg inducible defense trait, in comparison with the European maize line Delprim and North American inbred line B73. The (E)-caryophyllene production level and transcript abundance of TPS23, terpene synthase responsible for (E)-caryophyllene formation, were compared between Braz1006, Delprim, and B73 after mimicked herbivory. Braz1006-TPS23 was heterologously expressed in E. coli, and amino acid sequences were determined. Furthermore, electrophysiological and behavioral responses of a key parasitic wasp Cotesia sesamiae to C. partellus egg-induced Braz1006 volatiles were determined using coupled gas chromatography electroantennography and olfactometer bioassay studies. After elicitor treatment, Braz1006 released eightfold higher (E)-caryophyllene than Delprim, whereas no (E)-caryophyllene was detected in B73. The superior (E)-caryophyllene production by Braz1006 was positively correlated with high transcript levels of TPS23 in the landrace compared to Delprim. TPS23 alleles from Braz1006 showed dissimilarities at different sequence positions with Delprim and B73 and encodes an active enzyme. Cotesia sesamiae was attracted to egg-induced volatiles from Braz1006 and synthetic (E)-caryophyllene. The variation in (E)-caryophyllene emission between Braz1006 and Delprim is positively correlated with induced levels of TPS23 transcripts. The enhanced TPS23 activity and corresponding (E)-caryophyllene production by the maize landrace could be attributed to the differences in amino acid sequence with the other maize lines. This study suggested that the same analogous genes could have contrasting expression patterns in different maize genetic backgrounds. The current findings provide valuable insight not only into genetic mechanisms underlying variation in defense signal production but also the prospect of introgressing the novel defense traits into elite maize varieties for effective and ecologically sound protection of crops against damaging insect pests

    Development of genomic simple sequence repeat markers for yam

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    Yam ( Dioscorea spp.) is a major staple crop widely cultivated for its starchy tubers. To date, very few marker resources are publicly avail - able as tools for genetic and genomic studies of this economically important crop. In this study, 90 simple sequence repeat (SSR) markers were developed from an enriched genomic library of yellow Guinea yam ( D. cayenensis Lam.). Cross- amplification revealed that 85 (94.4%) and 51 (56.7%) of these SSRs could be successfully transferred to the two major cultivated species of D. rotundata Poir. and D. alata L., respec - tively. Polymorphisms in 30 markers selected on the basis of reliability and reproducibility of DNA bands were evaluated using a panel of 12 D. cayenensis , 48 D. rotundata , and 48 D. alata accessions. Accordingly, number of alleles per locus ranged from 2 to 8 in D. cayenensis (mean = 3.9), 3 to 30 in D. rotundata (mean = 13.9), and 2 to 22 in D. alata (mean = 12.1). The average observed and expected heterozygosi - ties were 0.156 and 0.634 ( D. cayenensis ), 0.326 and 0.853 ( D. rotundata ), and 0.247 and 0.836 ( D. alata ), respectively. Clustering based on six SSRs that were polymorphic in at least four of the five cultivated Dioscorea species studied, including D. cayenensis , D. rotundata , D. alata , D. dumetorum (Kunth) Pax., and D. bulbifera L., detected groups consistent with the phyloge - netic relationships of the species except for D. dumetorum . These new SSR markers are invalu - able resources for applications such as genetic diversity analysis and marker-assisted breedingYam ( Dioscorea spp.) is a major staple crop widely cultivated for its starchy tubers. To date, very few marker resources are publicly avail - able as tools for genetic and genomic studies of this economically important crop. In this study, 90 simple sequence repeat (SSR) markers were developed from an enriched genomic library of yellow Guinea yam ( D. cayenensis Lam.). Cross- amplification revealed that 85 (94.4%) and 51 (56.7%) of these SSRs could be successfully transferred to the two major cultivated species of D. rotundata Poir. and D. alata L., respec - tively. Polymorphisms in 30 markers selected on the basis of reliability and reproducibility of DNA bands were evaluated using a panel of 12 D. cayenensis , 48 D. rotundata , and 48 D. alata accessions. Accordingly, number of alleles per locus ranged from 2 to 8 in D. cayenensis (mean = 3.9), 3 to 30 in D. rotundata (mean = 13.9), and 2 to 22 in D. alata (mean = 12.1). The average observed and expected heterozygosi - ties were 0.156 and 0.634 ( D. cayenensis ), 0.326 and 0.853 ( D. rotundata ), and 0.247 and 0.836 ( D. alata ), respectively. Clustering based on six SSRs that were polymorphic in at least four of the five cultivated Dioscorea species studied, including D. cayenensis , D. rotundata , D. alata , D. dumetorum (Kunth) Pax., and D. bulbifera L., detected groups consistent with the phyloge - netic relationships of the species except for D. dumetorum . These new SSR markers are invalu - able resources for applications such as genetic diversity analysis and marker-assisted breedin

    Population Based Survey of Chronic Non-Communicable Diseases at Gilgel Gibe Field Research Center, Southwest Ethiopia

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    BACKGROUND: Chronic Non-communicable Diseases are increasingly becoming more prevalent and burden to the health care system in developing countries including Ethiopia. However, evidences showing the magnitude of the problem in those countries are scarce particularly in a community setting.The objective of this study was to determine the magnitude of chronic non communicable diseases in a community.METHODS: A population-based cross-sectional study was conducted in Gilgel Gibe Field Research Center from late September 2008 to end of January 2009. A random sample of 4,469 individuals aged 15-64 years was studied. Data on characteristics and chronic symptom inventories were collected by interviewing study participants. Blood pressure was taken three times from each individual and blood sugar and lipid levels were determined after an overnight fasting. Data were analyzed using SPSS for Windows version 16.0 and STATA 11.RESULTS: The overall prevalence of CNCD was 8.9% (7.8% men and 9.8% women). The specific observed prevalence were 0.5% for diabetes mellitus (DM), 2.6% for hypertension, 3.0% for cardiovascular diseases, 1.5% for asthma and 2.7% for mental illness. In addition 3.1% and 9.3% of the study population had been informed to have DM and hypertension respectively.CONCLUSION: There is a high prevalence of CNCD among the study population indicating an immediate need for preventive action and also warrant further nationally representative study.Keywords: CNCD, Non-communicable, Prevalence, Southwest Ethiopi

    Gap and opportunity analysis of hydrological monitoring in the Ziway-Shala Sub-basin, Ethiopia

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    This working paper was prepared under a development and conservation project – Societal Development and Ecosystems Conservation in Sahelian Wetlands (SAWEL) – focusing on improving food security and nutrition in the Sahel region by helping to safeguard wetlands through ecologically sustainable agricultural water management. SAWEL is supported by the Swiss Agency for Development and Cooperation (SDC). This paper provides an overview of the current situation with regards to hydrological monitoring in the Ziway-Shala sub-basin in the Central Rift Valley of Ethiopia, including details of existing river and lake gauging stations in the sub-basin. The study was jointly conducted by the International Water Management Institute (IWMI) and Hydrosolutions through consultation with staff of the Rift Valley Lakes Basin Development Office (RVLBDO), field trips to gauging stations, inspection of data recording books and reviewing previous studies. In addition to highlighting gaps in hydrological monitoring in the Ziway-Shala sub-basin, opportunities (e.g., remote sensing and citizen science) for novel, non-traditional hydrological monitoring are also presented

    Mating behaviour, mate choice and female resistance in the bean flower thrips (Megalurothrips sjostedti)

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    Many species of thrips (Thysanoptera) in the family Thripidae form mating aggregations, but the adaptive significance of these aggregations and the extent of male and female mate choice is poorly understood. We studied the mating behaviour of the bean flower thrips Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), which forms male aggregations and occurs across sub-Saharan Africa. We tested whether males choose mates by female age or mating status. No-choice mating bioassays with one male and one female were used to simulate the way males usually encounter only one female at a time in aggregations in the field. Virgin females violently resisted mating attempts by males, but we found no compelling evidence to establish whether this was indiscriminate or was screening suitable males. Younger males (1–2 days old) did not discriminate females by age (1–2 or 7–10 days old), but older males (7–10 days old) avoided mating with older females. Any male choice by female mating status (virgin or mated) was weak or absent. The mating behaviour of M. sjostedti shows broad similarities with that of other thrips species that form aggregations, but also shows some distinct and novel differences, which can help our understanding of the adaptive significance of aggregations

    Maize Chlorotic Mottle Virus Induces Changes in Host Plant Volatiles that Attract Vector Thrips Species

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    Maize lethal necrosis is one of the most devastating diseases of maize causing yield losses reaching up to 90% in sub-Saharan Africa. The disease is caused by a combination of maize chlorotic mottle virus (MCMV) and any one of cereal viruses in the Potyviridae group such as sugarcane mosaic virus. MCMV has been reported to be transmitted mainly by maize thrips (Frankliniella williamsi) and onion thrips (Thrips tabaci). To better understand the role of thrips vectors in the epidemiology of the disease, we investigated behavioral responses of F. williamsi and T. tabaci, to volatiles collected from maize seedlings infected with MCMV in a four-arm olfactometer bioassay. Volatile profiles from MCMV-infected and healthy maize plants were compared by gas chromatography (GC) and GC coupled mass spectrometry analyses. In the bioassays, both sexes of F. williamsi and male T. tabaci were significantly attracted to volatiles from maize plants infected with MCMV compared to healthy plants and solvent controls. Moreover, volatile analysis revealed strong induction of (E)-4,8-dimethyl-1,3,7-nonatriene, methyl salicylate and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene in MCMV-infected maize seedlings. Our findings demonstrate MCMV induces changes in volatile profiles of host plants to elicit attraction of thrips vectors. The increased vector contact rates with MCMV-infected host plants could enhance virus transmission if thrips feed on the infected plants and acquire the pathogen prior to dispersal. Uncovering the mechanisms mediating interactions between vectors, host plants and pathogens provides useful insights for understanding the vector ecology and disease epidemiology, which in turn may contribute in designing integrated vector management strategies
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