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1.
Belayneh Ayalew Desalegne Kifle Dagne Gedil Melaku Boukar Ousmane Christian A. Fatokun 《Journal of Crop Science and Biotechnology》2017,20(2):107-128
The extent of genetic diversity and relatedness of cowpea germplasm from East Africa are poorly understood. A set of 13 microsatellites (SSR) and 151 single nucleotide polymorphisms (SNPs) markers were applied to assess the levels of genetic diversity in a sample of 95 accessions of local cowpea germplasm and inbred lines of Vigna unguiculata. The average genetic diversity (D), as quantified by the expected heterozygosity, was higher for SSR loci (0.52) than for SNPs (0.34). The polymorphic information content was 0.48 for SSR and 0.28 for SNP while the fixation index was 0.095 for SSR and 0.15 for SNPs showing moderate differentiation and high gene flow among cowpea accessions from East African countries. The results of data analysis of both SSR and SNP markers showed similar clustering patterns suggesting a substantial degree of association between origin and genotype. Principal coordinate analysis (PCoA) with SSR and SNP markers showed that accessions were grouped into two and three broad groups across the first two axes, respectively. Our study found that SNP markers were more effective than SSR in determining the genetic relationship among East African local cowpea accessions and IITA inbred lines. Based on this analysis, five local cowpea accessions Tvu-13490, Tvu-6378, Tvu-13448, Tvu-16073, and 2305675 were identified to be tightly clustered sharing several common alleles with the drought tolerant variety Danila when analyzed with SSR and SNP markers. The findings will assist and contribute to future genetic diversity studies aimed at the genetic improvement of local Eastern Africa cowpea accessions for improved overall agronomic performance in general and breeding for drought tolerant in particular. 相似文献
2.
Lesnoff M Laval G Bonnet P Abdicho S Workalemahu A Kifle D Peyraud A Lancelot R Thiaucourt F 《Preventive veterinary medicine》2004,64(1):27-40
Contagious bovine pleuropneumonia (CBPP) is a major threat for cattle health and production in Africa. This disease is caused by the small-colony type of Mycoplasma mycoides subspecies mycoides (MmmSC). Transmission occurs from direct and repeated contacts between sick and healthy animals. Veterinary services recently reported a resurgence of CBPP in the province of West Wellega, in the Ethiopian highlands. A research program was set up to estimate the epidemiological parameters of the within-herd infection spread. A follow-up survey was implemented in 71 sampled herds of the Boji district (West Wellega province). Fifteen herds were classified as newly infected and used in a serological- and clinical-incidence study. The overall 16-month cumulative sero-incidence risk was 34%. Clinical cases were recorded for 39% of the seropositive cattle; case-fatality risk was 13%. There was no evidence of benefit on infection spread of CBPP-control measures used locally by farmers (isolation or antibiotic treatments of sick animals). This might be related to a lack of power in the statistical analyses or to a quality problem for the medications used (and more generally, for health-care delivery in the Boji district). 相似文献
3.
Serbessa Tolera Bekele Dagne Woldegebriel Kifle Teshome Gari Abel Geleta Dida Mulatu Tesfaye Geletu Kassahun 《Genetic Resources and Crop Evolution》2021,68(6):2337-2350
Anchote (Coccinia abyssinica (Lam.) Cogn.) is a perennial root crop belonging to Cucurbitaceae family. It is endemic to Ethiopia and distributed over wide range of agro-ecologies. For further improvement and efficient conservation of this crop, characterization of its genetic diversity and its pattern of distribution is a vitally important step. Expressed sequence tags-simple sequence repeats (EST-SSRs) markers were developed from publicly available watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] ESTs in the GenBank database. Among those novel markers, eight were polymorphic and subsequently used for genetic diversity and population structure analyses of 30 anchote accessions collected from western Ethiopia. A total of 24 alleles were obtained across the eight polymorphic loci and 30 accessions that revealed moderate level of genetic diversity in this minor crop. Among the eight loci, locus CA_06 was the most informative with six alleles and polymorphic information content (PIC) of 0.76. The accessions showed about threefold variation in terms of genetic diversity, with expected heterozygosity (He) ranging from 0.15 (accession An) to 0.44 (accession Dg). Other accessions with higher genetic diversity include Ar and Gu (He?=?0.43 and 0.41, respectively). Analysis of molecular variance (AMOVA) revealed that the variation within accessions and among accessions accounted for 84.7% and 15.3% of the total variation, respectively. The study revealed low but significant population differentiation in this crop with no clear pattern of population structure. The EST-SSR markers developed in this study are the first of their kind for anchote and can be used for characterization of its wider genetic resources for conservation and breeding purposes.
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Journal of Plant Diseases and Protection - Pre-harvest infection of groundnut (Arachis hypogea) during drought stress by strains of Aspergillus flavus and Aspergillus parasiticus is a major health... 相似文献
8.
Furanosesquiterpenes from Commiphora sphaerocarpa and related adulterants of true myrrh 总被引：2，自引：0，他引：2
A new furanosesquiterpene, (1E)-8,12-epoxygermacra-1,7,10,11-tetraen-6-one (3), was isolated from the resin of Commiphora sphaerocarpa together with the known compounds curzerenone (1), furanodienone (2), (1E)-3-methoxy-8,12-epoxygermacra-1,7,10,11-tetraen-6-one (4), (1(10)E,2R*,4R*)-2-methoxy-8,12-epoxygermacra- 1(10),7,11-trien-6-one (5), and dihydropyrocurzerenone (6). Hydrodistillates of the resins of C. sphaerocarpa, C. holtziana, C. kataf and C. myrrha were analysed. The identifications were aided by NMR, GC and GC-MS. 相似文献
9.
The study was conducted to evaluate surge irrigation against continuous irrigation in terms of irrigation and water use efficiencies
to produce onion. It was carried out at Mekelle Agricultural Research Center, Ethiopia on 70 m long and 0.6 m center–center
spacing furrows of 0.26% average slope on a clay soil. The treatments consisted of factorial combination of two discharges
(Q
1 = 1 l/s and Q
2 = 2 l/s) and three-cycle ratios (CR1 = 1/3, CR2 = 1/2, and C = 1 for continuous irrigation). Surge flow treatments advanced faster than the respective continuous flow treatments with
surge flow treatment SF21 being the fastest. The best value of application efficiency (60%) was achieved for SF11 and the least (46%) for CF2. The maximum (87%) and minimum (68%) values of distribution uniformity were obtained for cycle ratios CR1 and C, respectively. Storage efficiency was highest (89%) for CF2 and lowest (78%) for SF12. Onion yield was significantly affected (p < 0.05) by the interaction effect, the highest (14,400 kg/ha) and the lowest (13,363 kg/ha) yields were obtained for SF11 and SF21, respectively. The maximum irrigation water use efficiency (2.27 kg/m3) was observed for SF11 and the minimum (1.68 kg/m3) for CF2. Surge irrigation was found to be a promising irrigation practice for onion production in the study area as it saves water,
reduces irrigation period, and increases the crop yield. 相似文献
10.
Mulatu Geleta Tomas Bryngelsson Endashaw Bekele Kifle Dagne 《Genetic Resources and Crop Evolution》2007,54(3):601-614
Genetic diversity of 70 populations of niger (Guizotia abyssinica) representing all its growing regions in Ethiopia was investigated using random amplified polymorphic DNA (RAPD) to reveal
the extent of its populations genetic diversity. Ninety-seven percent of the loci studied was revealed to be polymorphic for
the whole data set. The within population diversity estimated by Shannon diversity index and Nei gene diversity estimates
was revealed to be 0.395 and 0.158, respectively. The extent of genetic variation of populations from major niger producing
regions was significantly lower than that of populations from other regions; however, it is distributed regardless of altitude
of growth. Genetic differentiation between populations was estimated with Shannon index as G′
ST (0.432), Nei’s G
ST (0.242) and AMOVA based F
ST (0.350) and appears to be equivalent to the average values calculated from various RAPD based studies on outcrossing species.
Higher proportion of the variation detected by AMOVA resided within populations (64.58%) relative to the amount of variation
among populations (35.42%). UPGMA cluster analysis showed that most of the populations were clustered according to their region
of origin. However, some populations were genetically distant from the majority and seem to have unique genetic properties.
It is concluded that the crop has a wide genetic basis that may be used for the improvement of the species through conventional
breeding and/or marker assisted selection. Collection of germplasm from areas not yet covered and/or underrepresented is the
opportunity to broaden the genetic basis of genebank collection. 相似文献