Improving adaptation to drought stress in white pea bean (Phaseolus vulgaris L.): Genotypic effects on grain yield,yield components and pod harvest index

Common bean (Phaseolus vulgaris L.) is the most important food legume crop in Africa and Latin America where rainfall pattern is unpredictable. The objectives were to identify better yielding common bean lines with good canning quality under drought, and to identify traits that could be used as selection criteria for evaluating drought‐tolerant genotypes. In all, 35 advanced lines were developed through single seed descent and evaluated with a standard check under drought and irrigated conditions at two locations over 2 years in Ethiopia. Grain yield (GY), pod number per m², seed number per m² and seed weight decreased by 56%, 47%, 49% and 14%, respectively, under drought stress. Eight genotypes had better yield with good canning quality under drought compared to the check. Moderate to high proportion of genetic effects were observed under drought conditions for GY and yield components compared to genotype × environment effects. Significant positive correlations between GY and pod harvest index (PHI) in drought suggest that PHI could be used as an indirect selection criterion for common bean improvement.     

Bovine fasciolosis: coprological, abattoir survey and its economic impact due to liver condemnation at Soddo municipal abattoir, Southern Ethiopia

A study was carried out to determine the prevalence and the species of liver flukes in indigenous adult cattle, to compare the diagnostic efficiency of fecal and post mortem examination and to assess the economic significance of bovine fasciolosis due to liver condemnation in the abattoir. Of the 406 livers and fecal samples examined, 57 (14.0%) and 20 (4.9%) were positive for fasciolosis. The most common liver fluke species affecting the cattle was Fasciola gigantica, 9.1% of cattle were infected with F. gigantica while, Fasciola. hepatica, mixed infections and unidentified or immature forms of Fasciola spp. were present in 3.2 %, 0.7% and 1 % of cattle, respectively. A retrospective abattoir survey revealed that the prevalence of fasciolosis was 12.7%. The prevalence of fasciolosis recorded in this study was lower than that reported by other researchers in this country. There was a strong relationship between fecal examination and postmortem findings of liver lesions, (K?=?0.23) but under local conditions, postmortem examination was considered a better diagnostic tool for fasciolosis. Fasciolosis is of significant economic importance as the resultant liver condemnations caused an average loss of 4000 USD per annum. Hence, this disease deserves serious attention by the various stakeholders in order to promote the beef industry in the study area in particular and in the country in general.     

Serological survey of African horse sickness in selected districts of Jimma zone,Southwestern Ethiopia

A cross-sectional serological survey was undertaken in selected districts of different agro-ecology of Jimma zone (Dedo, Yebu, Seka, Serbo, and Jimma town) from November 2009 to February 2010 to determine the seroprevalence of African horse sickness virus and associated risk factors of the disease. Two hundred seventy-four equids (189 horses, 43 mules, and 47 donkeys) with a history of non-vaccination for at least 2 years were selected randomly from the above areas. Sera samples were collected and assayed for the presence of specific antibody against African horse sickness virus using blocking ELISA. An overall seroprevalence of 89 (32.5%) was found and it was 24 (51.1%) for donkeys, 13 (30.2%) for mules, and 52(28.3%) for horses. Seroprevalence was significantly (X ² = 11.05, P < 0.05) different among the different species of equids. Seroprevalence was also significantly (X ² = 11.43, P < 0.05) different among the different agro-ecological areas being higher in highlands 47 (40.5%) followed by midland 30 (34.5%) and lowland 12 (16.9%). Age and sex were not significantly (X ² = 3.15, P > 0.05 and X ² = 3.38, P > 0.05, respectively) associated with seroprevalence of AHSV. The present study showed that African horse sickness (AHS) is highly prevalent disease for the horses followed by mules and then donkeys in Jimma zone explained by lower seroconversion rate. Therefore, control strategy against AHS should target at high risk species of all age and sex in their locality in the initial stage for better containment of the disease.     

Informal surveys to assess social forestry at Dibandiba and Aleta Wendo,Ethiopia

Two surveys were carried out at Dibandiba, a semi-arid site in central Ethiopia, and Aleta Wendo, a sub-humid site in southern Ethiopia, to assess farmers' attitudes toward and perceptions of tree planting, levels of social forestry and uses of tree products. At Dibandiba, farmers planted mostlyEucalyptus camaldulensis trees, exclusively on homesteads andAcacia albida was left on farmland. Trees were planted mainly for construction (32%), fuelwood (29%), shade (11%) and cash (11%). Major (85%) uses were fencing, fuelwood, construction and plough handles. Dung was the major source of fuel (56%). At Aleta Wendo, planting consisted ofEucalyptus globulus mostly on private woodlots and homesteads, ofMilletia ferruginea andCordia abyssinica on farms, and ofEuphorbia abyssinica on fences and boundaries. Avocado and pears were also planted. The uses were the same as at Dibandiba. Major constraints were lack of seedlings and shortage of land at both sites, plus shortage of water at Dibandiba. Also, a review of information obtained from previous surveys on household composition and income, farm holding, cropping pattern, livestock composition and the use of labour was made.     

Variation between and within Ethiopian barley landraces

Up to 100 single plant derived lines of 18 barley landraces, collected from 18 localities of six barley growing regions of Ethiopia were studied for two years at Holetta, Ethiopia for variation in five quantitative traits; scald severity, earliness, plant height, 1000 grain weight, and leafiness. The relative latent period in the adult plant stage to barley leaf rust, a good measure for partial resistance, was assessed on the landrace lines at Wageningen, The Netherlands. The observed variation between and within landraces was very large for all traits. The magnitude of variation was so large that most, if not all, plants within a landrace had a different genotype. The landraces also varied in the degree of variation. Some landraces, 1726 and 3288 for instance, were more variable for most or all traits than other landraces such as 208925 and 212938. Days to heading and scald severity were significantly (P = 0.01) correlated with altitude, r being 0.66 and - 0.65, respectively. Resistance to scald and leafiness also increased with altitude. On average landraces became later, more resistant to scald and more leafy the higher the altitude of collection. This associated complex of traits could be an adaptation to the wetter and cooler conditions at higher altitudes. This revised version was published online in July 2006 with corrections to the Cover Date.     

Variation and inheritance of erucic acid content in Brassica carinata germplasm collections from Ethiopia

Ethiopian mustard possesses a number of agronomic advantages over other oilseed crops with similar ecological adaptation in Ethiopia. However, its high erucic acid content is undesirable for a vegetable oil. Although efforts have been made to improve its quality, much has to be done to use natural variations that might exist within the species for fatty acid contents. This project was undertaken to study the variability of fatty acid contents, primarily erucic acid, in germplasm collections of Ethiopian origin, with an attempt to develop low (zero) erucic acid genotypes. The study used inbred lines as well as F₂ populations of 10 crosses between six parental lines. A wide variation in fatty acids was found. Oleic acid content varied from 5 to 34% and erucic acid content from 6 to 51%. Linoleic and linolenic acid contents were less variable. The high‐oleic genotypes exhibited not only low erucic but also higher linoleic (25%) and considerably lower linolenic acid (8%) contents. It was possible to classify the F₂ populations with the lowest erucic acid into three distinct classes. While the first class had an erucic acid content of 6–12%, the second and third classes had contents of 18–32% and 36–42%, respectively. The existence of a multiple allelic series of erucic acid in Ethiopian mustard would enable its fixation at zero levels without necessarily going into interspecific crossing.     

Inverse Sequence-tagged Repeat (ISTR) Analysis of Genetic Variability in Forest Coffee (Coffea arabica L.) from Ethiopia

Genetic diversity in forest coffee (Coffea arabica L.) was estimated using inverse sequence-tagged repeat (ISTR) markers. One hundred ninety two samples representing 16 populations of C. arabica from four regions of Ethiopia were analyzed with 12 pairs of forward and backward ISTR primer combinations. A total of 144 reproducible bands were generated out of which 37 (25%) were polymorphic and scored as present (1) or absent (0) data matrix. This data was used to compute Jaccard coefficient to estimate genetic variability among all possible pairs of samples. The proportion of polymorphic bands within populations ranged from 19% for Bale-3, to 54% for Walega-2 populations. Un-weighted pair group method with arithmetic mean (UPGMA) based cluster analysis generated two clusters at 56% similarity value. The samples were clustered on the basis of their geographical origin, which could be attributed to a few region specific banding patterns detected. However, within regions most of the samples failed to cluster on the basis of their respective populations, which may be due to the presence of substantial gene flow between local populations in the form of seedlings carried out by farmers. The results may provide information to develop strategies for in situ conservation.     

Genotypic diversity and patterns of variation in a germplasm material of Ethiopian mustard (Brassica carinata A. Braun)

The amphidiploid species Brassica carinata A. Braun is believed to have originated in the plateaus of Ethiopia and has been cultivated there as an oilseed crop since antiquity. The species possesses agronomically important genes of rare occurrence. Although there is a large number of collections in Ethiopia, information on the extent of their genetic diversity is very limited. Thirty-six accessions of ecologically diverse regions were tested at three locations and multivariate analyses on 13 morphological and seed characters were performed. There was generally a large amount of divergence in all characters. Geographic isolation of genes, however, was not observed. Both principal component and cluster analyses disclosed complex relationships among the accessions and characters. Accessions with potential genes of interest to improve earliness, yield components and oil and protein contents have been identified. Length of growing period and yield components contributed most for divergence and clustering pattern. Oil, glucosinolate and protein contents also varied among the accessions but not so much between clusters. Increasing protein in high-glucosinolate genotypes reduced oil content and should be more efficient in genotypes of low-glucosinolate genetic background.