Screening of Ethiopian sorghum (Sorghum bicolor) landraces for their performance under Striga hermonthica ‐infested conditions

Striga hermonthica is a major constraint to sorghum production and productivity in sub‐Saharan Africa, Ethiopia, in particular. The objectives of this study were to evaluate the performance of 49 sorghum genotypes based on their reaction to S. hermonthica and investigate the relationships among yield and Striga resistance traits, including the Striga emergence count, area under Striga number progress curve, area under Striga severity progress curve, grain yield under infested, grain yield under non‐infested conditions and relative yield loss. The genotypes differed significantly in all measured parameters under Striga‐infested and non‐infested conditions. The genotypes ‘Birhan’, ‘Gubiye’, Wolegie, Zegerie, Nechmashila I, Woftel, Tetron and Eyssa were identified as promising ones based on grain yield and Striga‐related traits. On the other hand, the genotypes Jamyo, Bobie, Gedido, Mankebar and Zengada had moderate Striga numbers with low relative yield loss as compared with susceptible checks. The most promising variety, Zegerie, Mankebar and Zengada, out yielded the standard resistant checks ‘Birhan’ and ‘Gubiye’ under Striga infestation. Ward cluster analysis grouped the 49 sorghum genotypes in to four distinct clusters under Striga‐infested conditions. All members of clusters II and III showed the highest yielding group with the lowest to moderate Striga number, while cluster IV supported the lowest yield with the highest Striga number. Significant negative correlations were observed between yield‐ and Striga‐related traits. Highly significant and strong correlations were observed among Striga resistance indices, indicating that any of the Striga resistance parameters can be used as an indicator of resistance. The wide variations in grain yield among genotypes under Striga‐infested conditions would be invaluable genetic resources for production in Striga endemic areas of Ethiopia.     

Effect of Citrate Concentration on the Extraction Efficiency of Selected Micronutrients from Soil

This study was carried out with the objective of evaluating the effect of citrate concentration on the extraction efficiency of some micronutrients from soil. Composite surface soil samples (0–20 cm) were collected from Eastern Harage Zone (Babile and Haramaya Districts), Wolaita Zone (Damot Sore, Boloso Bombe, Damot Pulasa and Humbo Districts) and Dire Dawa Administrative Council in purposive sampling. The treatments were arranged in completely randomized design (CRD) with three replications. A greenhouse pot experiment with soybean plant was conducted to determine the correlation between soil test methods and the selected micronutrients, such as iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn) in the leaves of the plant. The results showed that, among the different citrate concentrations with strontium chloride (SrCl₂) tested for the determination of available Fe, Mn and Zn, the highest correlation coefficients (r = 0.82, p < 0.05), (r = 0.96, p < 0.001) and (r = 0.98, p < 0.001) were found between the diethylenetriamine pentaacetic acid (DTPA) method and 0.02 M strontium chloride (SrCl₂)-0.025 M citric acid extractant, respectively. Therefore, 0.02 M SrCl₂-0.025 M citric acid extractant is considered to be the most effective for the determination of Fe, Mn and Zn in soils of the studied areas. Similarly, high correlation coefficients (r = 0.97, p < 0.001) were found between DTPA and 0.02 M SrCl₂-0.05 M citric acid and (r = 0.88, p < 0.01) between DTPA and 0.02 M SrCl₂-0.025 M citric acid extractants for the determination of available Cu from soils. Hence, the 0.02 M SrCl₂-0.05 M citric acid extractant was shown to be the best for the determination of Cu in soils of the studied areas. However, considering the use of universal extractant, the 0.02 M SrCl₂-0.025 M citric acid extractant could easily be adopted as a procedure for the determination of Fe, Cu, Mn and Zn for both agricultural and environmental purposes. The greenhouse experiment confirmed the result.     

Cardiovascular complications of chronic catheterization of the jugular vein in the dog

Cardiovascular changes associated with indwelling catheters were evaluated in 51 adult beagle dogs catheterized for 4 to 9 weeks. Pathologic changes consistent with traumatic injury were in the vena cava and endocardium of the right atrium of 88% of cannulated dogs. Lesions were characterized by surface denudation and diffuse intimal thickening due to myointimal hyperplasia and deposition of extracellular matrix. Affected intima was lined by hyperplastic, poorly differentiated endothelial cells and contained round to oval cells with characteristics of smooth muscle cells. After 9 weeks, thickened intima was vascularized and composed of spindle-shaped cells and fibrillar stroma. Intimal sclerosis and localized proliferative papillary projections in the vena cava cranial to areas of myointimal hyperplasia occurred infrequently. Traumatic lesions, regardless of location or severity, did not extend below the internal elastic membrane. Inflammatory cellular responses, when present, were minimal. The location, distribution, and morphogenesis of catheter-related cardiovascular lesions distinguishes them from those induced by chemical toxicity or pharmacotoxicity.     

Management options to accelerate growth rate and reduce age at first calving in Friesian–Boran crossbred heifers

Two experiments were conducted simultaneously to evaluate the effects of different concentrates to roughage ratios on growth performance and attainment of puberty in Friesian–Boran crossbred heifers. Weaned 50% Friesian–Boran crossbred female calves were used in both experiments with 25 and 20 calves in experiments I and II, respectively. In experiment I, the calves were offered diets with concentrate to roughage ratios of 50:50 (treatment 1) or 30:70 (treatment 2). In experiment II, the calves grazed for 8 h a day and supplemented with 2 kg hay and 1 kg concentrate per head per day (treatment 1) or only 2 kg hay per head per day (treatment 2). The concentrate mixture was composed of 34% wheat bran, 31% wheat middling, 31% noug cake, 3% limestone, and 1% salt. In experiment I, heifers fed a ration with 50% concentrate and 50% roughage had higher (P < 0.05) daily body weight gain (0.532 kg) and attained puberty at 221 kg (65% of the mature body weight) in 15 months, while heifers fed a diet with 30% concentrate and 70% roughage gained 0.434 kg/day and reached puberty at 247 kg (70% of the mature body weight), about 3 months later. Heifers in treatments 1 and 2 of experiment II reached puberty 5 and 12 months later, respectively, than those in experiment I. In experiment II, heifers given 1 kg of concentrate supplement had higher (P < 0.05) daily body weight gain (0.346 kg) than those given only 2 kg hay in addition to grazing (0.278 kg). Growth rate of crossbred heifers was enhanced and age at puberty was reduced by changing the rearing management from outdoor to indoor and with increasing level of concentrate in the ration. This helps to bring the dairy heifer into production earlier and enhance to the overall productivity of the dairy industry.     

A streak disease of pearl millet caused by a leafhopper-transmitted geminivirus

The cause of a streak disease of pearl millet (Pennisetum glaucum), originating from Nigeria, has been attributed to a geminivirus belonging to the African streak virus cluster. A full-length, infectious clone of the virus was obtained which was transmissible by the vectorCicadulina mbila (Naudé). Analysis of the complete nucleotide sequence of the coat protein gene of this virus shows it to be most closely related to sugarcane streak virus. The possible evolutionary implications of this finding are discussed.     

First confirmation of foot and mouth disease virus serotype SAT-1 in cattle and small ruminants in Ethiopia in 2007/08

The study was conducted in three regional states of Ethiopia: Amhara, Oromia, and the Southern Nations Nationalities and people regional state from August 2007 to April 2008 with the objective of identifying the foot and mouth disease virus (FMDV) serotypes circulating in the region. Two serotypes were recorded from epithelial tissue and oesophageal–pharyngeal (OP) fluid that were taken from outbreaks in study regions of Ethiopia. Serotype O FMDV was identified in Girar Jarso, Yabello, and Ankesha Guagusa districts while SAT-1 was isolated in Surma and Maji districts from tissue samples and this was the first report of the FMDV serotype in Ethiopia. Similarly, the OP fluid samples were found positive for SAT-1 FMDV in Maji and Surma districts.     

Increased grain protein content and its association with agronomic and end-use quality in two hard red spring wheat populations derived from Triticum turgidum L. var. dicoccoides

Suitability of wheat (Triticum aestivum L.) for many food products depends on its unique protein. Elevated grain protein content (GPC) and its quality influences the bread making properties of wheat. The objective of this study was to examine the association of elevated GPC with agronomic and end-use quality in two hard red spring wheat recombinant inbred (RI) populations derived from wild emmer (Triticum turgidum L. var. dicoccoides). The two hard red spring populations (ND683/Bergen and Glupro/Bergen) were developed using a single-seed-descent method. ND683 and ‘Glupro’ are high in GPC (180 g kg^-1), presumably due to the introgression of gene(s) from Triticum turgidum L. var. dicoccoides and ‘Bergen’ is low in GPC (145 g kg^-1). From each of the two populations 12 high- and 12 low-GPC RI lines (F_5:7) were selected for replicated testing at two North Dakota (ND) locations in 1995. In both populations, the high-GPC lines had significantly (p < 0.05) higher values compared to the low-GPC lines for mean GPC and water absorption. Mean grain yield of the high-GPC lines was not significantly different from the low-GPC lines in both populations. In the ND683/Bergen population, the high-GPC lines had significantly (p < 0.05) higher values than the low-GPC lines for mean plant height, days to heading, and flour extraction. GPC was significantly (p < 0.05)and negatively associated with test weight and also significantly (p < 0.01) and positively associated with water absorption in the Glupro/Bergen population. In these populations, results suggested that it may be possible to select lines that combine higher GPC and acceptable yield level, but later in maturity and taller in plant height. This revised version was published online in July 2006 with corrections to the Cover Date.     

Molecular characterization of Newcastle disease viruses isolated from rural chicken in northwest Ethiopia reveals the circulation of three distinct genotypes in the country

Newcastle disease (ND) is a highly contagious disease that affects many species of birds and causes significant economic losses to the poultry industry worldwide. Fifteen Newcastle disease virus (NDV) isolates obtained from rural chickens in northwest Ethiopia in 2011 and 2012 were characterized genotypically. The main functional region of the F gene was amplified and sequenced (260 nucleotides). Among the Ethiopian NDV isolates, 2 isolates had the virulent motif ¹¹²R-R-Q-K-R-F¹¹⁷ at the cleavage site of the fusion protein while 13 isolates contained the lentogenic motif ¹¹²G-G/R-Q-G-R-L¹¹⁷. Phylogenetic analysis based on the variable region of the F gene indicated that the two isolates exhibiting the virulent motif belonged to lineage 5 (genotype VII) subgenotype d and the remaining 13 isolates were grouped into lineage 2 (genotype II). The nucleotide sequences of lineage 5 isolates were genetically related to the Sudanese NDV isolates, suggesting potential epidemiological link of ND outbreaks between neighbouring countries. The lentogenic strains shared similarities with La Sota vaccine strain and probably originated from the vaccine strain either through direct exposure of birds to the live vaccine or to infectious La Sota-like strains circulating in rural poultry. This study provides genetic evidence on the existence of different NDV genotypes circulating in the rural poultry in Ethiopia. The virulent NDV continues to be a problem in poultry sector in Ethiopia, and their continuous circulation in rural and commercial poultry calls for improved surveillance and intensified vaccination and other control measures.