Mating biology,nuclear DNA content and genetic diversity in spider plant (Cleome gynandra) germplasm from various African countries          下载免费PDF全文

Emmanuel O. Omondi  Thomas Debener  Marcus Linde  Mary Abukutsa‐Onyango  Fekadu F. Dinssa  Traud Winkelmann 《Plant Breeding》2017,136(4):578-589

Cleome gynandra (L.) Briq. is an African leafy vegetable with a potential to improve food security and micronutrient deficiencies. Cytological traits, breeding biology and genetic diversity of 30 selected entries of C. gynandra from six African countries were investigated. The entries consisted of advanced lines, gene bank accessions and farmers’ cultivars. Our study revealed chromosome numbers of 2n = 34 in root tip metaphase cells from one entry. The 30 entries were found to be diploid with genome sizes ranging from 2.31 to 2.45 pg/2C. Hand pollination experiments were carried out to assess self‐incompatibility within the entries and revealed that they are self‐ and cross‐compatible. For genetic diversity studies within and among the entries, the pooled data of 499 polymorphic bands from 11 amplified fragment length polymorphism primer combinations and nine simple sequence repeat markers were used. The genetic distance among the entries ranged from 0.13 to 0.77. In a principal coordinate analysis, the farmers’ cultivars formed a cluster separate from the advanced lines and the gene bank entries, and the latter were not well resolved.  相似文献   

Genomics,genetics and breeding of tropical legumes for better livelihoods of smallholder farmers     

Chris Ojiewo  Emmanuel Monyo  Haile Desmae  Ousmane Boukar  Clare Mukankusi‐Mugisha  Mahendar Thudi  Manish K. Pandey  Rachit K. Saxena  Pooran M. Gaur  Sushil K. Chaturvedi  Asnake Fikre  NPVR Ganga Rao  CV SameerKumar  Patrick Okori  Pasupuleti Janila  Jean Claude Rubyogo  Chigeza Godfree  Essegbemon Akpo  Lucky Omoigui  Stanley Nkalubo  Berhanu Fenta  Papias Binagwa  Michael Kilango  Magdalena Williams  Omari Mponda  David Okello  Mekasha Chichaybelu  Amos Miningou  Joseph Bationo  Dramane Sako  Sory Diallo  Candidus Echekwu  Muhammad Lawan Umar  Richard Oteng‐Frimpong  Haruna Mohammed  Rajeev K. Varshney 《Plant Breeding》2019,138(4):487-499

Legumes are important components of sustainable agricultural production, food, nutrition and income systems of developing countries. In spite of their importance, legume crop production is challenged by a number of biotic (diseases and pests) and abiotic stresses (heat, frost, drought and salinity), edaphic factors (associated with soil nutrient deficits) and policy issues (where less emphasis is put on legumes compared to priority starchy staples). Significant research and development work have been done in the past decade on important grain legumes through collaborative bilateral and multilateral projects as well as the CGIAR Research Program on Grain Legumes (CRP‐GL). Through these initiatives, genomic resources and genomic tools such as draft genome sequence, resequencing data, large‐scale genomewide markers, dense genetic maps, quantitative trait loci (QTLs) and diagnostic markers have been developed for further use in multiple genetic and breeding applications. Also, these mega‐initiatives facilitated release of a number of new varieties and also dissemination of on‐the‐shelf varieties to the farmers. More efforts are needed to enhance genetic gains by reducing the time required in cultivar development through integration of genomics‐assisted breeding approaches and rapid generation advancement.  相似文献   

Stimulatory effect of dietary clove,Eugenia caryophyllata,bud extract on growth performance,nutrient utilization,antioxidant capacity,and tolerance of African catfish,Clarias gariepinus (B.), to Aeromonas hydrophila infection     

Ibrahim Adeshina  Adetola Jenyo‐Oni  Benjamin O. Emikpe  Emmanuel K. Ajani  Mohsen Abdel‐Tawwab 《Journal of the World Aquaculture Society》2019,50(2):390-405

The occurrence of pathogenic bacteria, Aeromonas hydrophila, in farm‐raised fish requires urgent attention. Continuous and indiscriminate use of antibiotics as growth promoters and disease control agents in aquaculture have been discouraged because of the risk of development of antibiotic‐resistant bacterial strains. There is steady interest in the use of botanicals, such as clove, Eugenia caryophyllata, buds extract (ECBE), as alternatives. Hence, the present study evaluated the effect of dietary ECBE supplementation on the growth performance, physiological, antioxidant, and immunity biomarkers of African catfish, Clarias gariepinus. Fish (11.7 ± 0.5 g) were fed diets containing 0.0 (control), 5.0, 10.0, or 15.0 g ECBE/kg diet up to apparent satiation twice daily for 12 weeks. After the feeding trial, fish from each treatment were challenged with A. hydrophila infection by intraperitoneal injection and kept under observation for 14 days to record any abnormal clinical signs and daily mortality. The results demonstrated that fish performance and feed intake were significantly enhanced with increasing ECBE levels, and its optimum level is 15 g/kg diet. Further, the dietary ECBE increased significantly the intestinal villi length/width and absorption area in a dose‐dependent manner. There are significant progressive increases in the values of red blood cells, hemoglobin, hematocrit, white blood cells, platelets, lymphocytes, and heterocytes, while monocytes, eosinophil, and basophils decreased significantly due to dietary ECBE in a dose‐dependent manner. Highest glucose, cholesterol, total protein, globulin, and albumin‐globulin ratios, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea, and creatinine values were found in fish fed 15 g ECBE/kg diets, while lowest values were recorded in fish fed the control diet. Despite the high AST and ALT values, no visible lesions or damage were observed in the liver cells of fish fed ECBE‐enriched diets. In addition, the inclusion of ECBE in fish diets enhanced the antioxidant and immunity capacity. Fish mortality after the bacterial challenge was higher in fish fed the control diet (82.3%) than those fed ECBE‐enriched diets. The lowest fish mortality was observed in fish fed the 15 ECBE/kg diet (4.7%) [Correction added on 16 November 2018: this section has been revised for clarity.].  相似文献   

Wildlife as a source of protein in Africa South of the Sahara     

Emmanuel O.A. Asibey 《Biological conservation》1974,6(1):32-39

The protein deficiency problems of Africa south of the Sahara are growing in seriousness with the increasing human population. Domestic livestock, on which very high hopes have hitherto been set, have continued to fail to meet existing demands, let alone to keep in step with increasing human population growth. There has been increasing exploitation of the meat of wild animals, whose management is ignored. This source of meat supplements domestic sources. The exploitation of wild animals, coupled with increasing pressure on the habitat of the animals, is exterminating most of the wild animal species involved. Advice that existing scientific knowledge on the management of wild animals must be applied to ensure their rational exploitation on a sustained-yield basis, has continued to be ignored— with the excuse that facts and figures are not available to justify investment in wildlife conservation that will ensure a sustained yield of the badly-needed animal protein. Every attempt must be made by those entrusted with the responsibility of wildlife conservation to bring together scattered information on the subject and, at the same time, begin to collect, systematically, statistical information on the utilization of wild animal meat as food—also to ensure that wildlife conservation receives the priority it deserves in the management of natural resources in Africa south of the Sahara. This is inevitable if wildlife conservation is to be able to meet the economic justification without which one nation after another will continue to give very low priority to wildlife conservation—to the detriment of the region—where malnutrition and poaching are serious realities as are also overgrazing, expansion of desert land, and human population explosion. Despite the fact that general experience indicates the need for concerted action, it appears that, in the absence of readily-available statistical data, which are supposed to be required by policy-makers and financiers, these people are not prepared to face their duty effectively to finance proper wildlife conservation and rational utilization of wildlife resources of Africa south of the Sahara.  相似文献   

Genetic differences for nitrogen uptake and nitrogen utilisation efficiencies in winter wheat     

Jacques Le Gouis  Denis B  ghin  Emmanuel Heumez  Pierre Pluchard 《European Journal of Agronomy》2000,12(3-4):163-173

Due to economic and ecological factors, European agricultural practices are likely to go towards extensive systems with lower inputs of nitrogen (N) fertilisers. The objective of this study was to assess varietal differences for N use at two nitrogen levels. A set of 20 winter wheat (Triticum aestivum L.) genotypes was studied over 2 years in northern France on a deep loam soil without (N0) and with 170 kg ha⁻¹ N fertiliser (N+) as ammonium nitrate. Results were consistent on both years as the genotype×year or genotype×year×N level interactions were not significant. The genotype×N level interaction was highly significant except for total N utilisation efficiency (total above-ground dry weight/total above-ground N) and grain N concentration. The genotype×N level interaction for grain yield was mainly due to three contrasting genotypes: Cappelle, a cultivar from the 1940s, had the same yield at N0 and N+; Arche had a high yield at both N levels; and Récital had a high yield with added N and a very low one without N. The number of kernels/ear explained most of the variations of grain yield at N0 (48%) and N+ (80%), and of the interaction (67%). N uptake efficiency (total above-ground N/soil N supply) accounted for 64% of the variation in N use efficiency (grain yield/soil N supply), while at N0 and at N+ it accounted for only 30%. N utilisation efficiency (grain yield/total above-ground N) was then more important at N+ than at N0. Grain N explained most of total plant N variation at both N levels. The interaction for N use efficiency was best explained by the interaction of N uptake (63%). The applications of these results to a breeding programme to create varieties adapted to low-input management systems are discussed.  相似文献   

A new process for the management of olive oil mill waste water and recovery of natural antioxidants     

Agalias A  Magiatis P  Skaltsounis AL  Mikros E  Tsarbopoulos A  Gikas E  Spanos I  Manios T 《Journal of agricultural and food chemistry》2007,55(7):2671-2676

The high polyphenol content of the wastewater is the major environmental problem caused by the olive mills. A pilot scale system for the treatment of the olive oil mills wastewater was developed aiming at the recovery of high added value-contained polyphenols and the reduction of the environmental problems. The treatment system consists of three main successive sections: The first one includes successive filtration stages aiming at the gradual reduction of the wastewater suspended solids up to a limit of 25 microm. The second section includes passing of the filtered wastewater through a series of adsorbent resins (XAD16 and XAD7HP) in order to achieve the de-odoring and decolorization of the wastewater and the removal/ recovery of the polyphenol and lactone content. The third section of the procedure includes the thermal evaporation and recovery of the organic solvents mixture, which has been used in the resin regeneration process, and finally the separation of the polyphenols and other organic substance contents using fast centrifuge partition chromatography. The final outcome of the whole procedure is (i) an odorless yellowish wastewater with a 99.99% reduced content in polyphenols and 98% reduced COD, (ii) an extract rich in polyphenols and lactones with high antioxidant activity and high added value, (iii) an extract containing the coloring substances of the olive fruit, and (iv) pure hydroxytyrosol.  相似文献   

Performance evaluation of a competitive ELISA test used for bluetongue antibody detection in France, a recently infected area     

Biteau-Coroller F  Gerbier G  Stärk KD  Grillet C  Albina E  Zientara S  Roger F 《Veterinary microbiology》2006,118(1-2):57-66

In 1998, bluetongue (BT) was introduced in northern Africa and then extended to northern latitudes including the French island of Corsica. Following the outbreaks in Corsica in 2000 and 2001, cross-sectional studies and surveillances have been set up in Corsica and also in the southern part of mainland France, a disease-free area but considered at high risk because of its proximity. The surveillance was based on regular blood sampling of susceptible species and antibody detection by a commercial competitive ELISA kit (cELISA). The performance of this cELISA was evaluated on both field results obtained during the 2001 surveillance campaigns and experimental results. ROC analyses were carried out using RT-PCR results as gold standard for determining the infection status of animals. From all these sets of data, cut-off values optimising the diagnostic accuracy of the test were computed. Their values ranged around the manufacturer's 50% threshold from 41% to 63%. The area under the ROC curve obtained from field data was 0.843 (95% CI: 0.762-0.923). In all our results, it appeared also that the specificity of the cELISA test was always perfect if the cut-off was at least at 80%. This cELISA test does not seem sufficient to diagnose BT disease in animals with BT-like symptoms. However, complementary data are needed to better estimate sensitivity and specificity values of this BT test for its use either as a diagnostic tool in infected areas or as a screening test in BT-free areas. The use and validity of RT-PCR results as gold standard are discussed. As the lack of suitable data strongly limited the applicable analyses, a discussion based on the OIE recommendations about test evaluation is initiated.  相似文献   

Planetary science. Titan's zoo of clouds     

Lellouch E 《Science (New York, N.Y.)》2006,311(5758):186-187

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Epidemiology of Trypanosoma vivax infection in cattle in the tse-tse free area of Lake Chad     

Delafosse A  Thébaud E  Desquesnes M  Michaux Y 《Preventive veterinary medicine》2006,74(2-3):108-119

A study was conducted in Chad to estimate the prevalence and the incidence of Trypanosoma vivax infection in herds of cattle from the Lake Chad area. The risk factors associated with disease were also identified. A random sample of 933 cattle from 17 herds was initially selected (January 1999, cold dry season). Cattle were identified by ear-tags and sampled in the rainy season (July 1999) and the cold dry season (January 2000). Each animal sampled was treated with diminazene aceturate (3.5mg/kg). Samples were examined for the presence of T. vivax using an antibody (indirect ELISA) and a parasite detection test (buffy-coat technique, BCT). Standardized questionnaires with information about the host and management practices were collected and evaluated for their association with seroprevalence (model 1) and parasitological prevalence (model 2) as indicator of host susceptibility to T. vivax infection. Risk factors were selected using two approaches: ordinary logistic regression (OLR) and generalized estimating equations (GEE) to account for within-herd correlation. The apparent prevalence was 1.6% using BCT and 42.3% with indirect ELISA. The true prevalence in the sample was estimated to (2.0%-8.0%) with two assumptions of BCT sensitivity. Overall, 58.8% (BCT) and 100.0% (ELISA) of the herds had a least one-positive animal. In January-July 1999, apparent monthly incidence was calculated at 0.24% in comparison with 0.76% for August 1999-January 2000. The true monthly incidence was estimated at 0.36%-1.43% for the first period and at 0.94%-3.78% for the second period. Risk factors associated with seroprevalence were age, race, a great number of small ruminants in the herd, and latitude and longitude of pasture area in the rainy season. Risk factors associated with BCT prevalence were duration of seasonal migration and longitude of pasture area in the rainy season. In conclusion, T. vivax is present and widely disseminated in the cattle herds of tse-tse free area of Lake Chad. Farm-level factors, particularly seasonal migration, should be considered as the main risk factors for infection and to host susceptibility to the parasite.  相似文献   

Genetic data from avian influenza and avian paramyxoviruses generated by the European network of excellence (EPIZONE) between 2006 and 2011--review and recommendations for surveillance     

Dundon WG  Heidari A  Fusaro A  Monne I  Beato MS  Cattoli G  Koch G  Starick E  Brown IH  Aldous EW  Briand FX  Le Gall-Reculé G  Jestin V  Jørgensen PH  Berg M  Zohari S  Metreveli G  Munir M  Ståhl K  Albina E  Hammoumi S  Gil P  de Almeida RS  Smietanka K  Domańska-Blicharz K  Minta Z  Van Borm S  van den Berg T  Martin AM  Barbieri I  Capua I;EPIZONE Network of Excellence Molecular Epidemiology of AI;APMV working group 《Veterinary microbiology》2012,154(3-4):209-221

Since 2006, the members of the molecular epidemiological working group of the European "EPIZONE" network of excellence have been generating sequence data on avian influenza and avian paramyxoviruses from both European and African sources in an attempt to more fully understand the circulation and impact of these viruses. This review presents a timely update on the epidemiological situation of these viruses based on sequence data generated during the lifetime of this project in addition to data produced by other groups during the same period. Based on this information and putting it all into a European context, recommendations for continued surveillance of these important viruses within Europe are presented.  相似文献