General Biology

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The Abo Blood Group and Plasmodium Falciparum Malaria in Awash, Metehara and Ziway Areas, Ethiopia.
(Addis Ababa University, 2008-07-05) Tekeste Zinaye; Petros Beyene (Professor)
The study aimed at investigating the relationship between blood group type and severe disease in P.falciparum malaria in three Ethiopian malaria endemic localities. A total of 210 cases of malaria (70 severe and 140 uncomplicated) and 190 healthy controls participated in the study. In the severe malaria category, there were 25 (35.7%), 15 (21.4%), 14 (20%) and 16 (22.9%) blood group A, B, AB and O patients respectively. Blood group O was the dominant blood type in both uncomplicated malaria (45.7%) and healthy controls (41.6 %). As compared to the uncomplicated malaria, a case of severe malaria was almost twice as likely to be of type A as to be of type O (O vs. A, odds ratio 0.42, 95% confidence interval 0.2007- 0.8789), and more than twice as likely to be of type B as to be of type O (O vs. B, odds ratio 0.38, 95% confidence interval 0.1638-0.8973), and in both cases the difference was statically significant (P=0.019 for O vs. A; P= 0.02 for O vs. B). Furthermore, individuals with severe malaria were about seven fold less likely to be of O as to be of type AB (O vs. AB, odds ratio 0.19, 95%; P=0.0005). There was significantly low mean hemoglobin concentration in the severe malaria patients than the uncomplicated malaria and healthy controls (P <.0001). Although the mean parasite density in individuals with severe malaria was higher than in those with uncomplicated malaria, the difference was not significant (P=0.35). Blood group O malaria patients had high mean hemoglobin concentration than those with blood group A, B, or AB, with significant difference only between blood group O and A (P=0.012), and blood group O and B (P=0.050). Furthermore, blood group O malaria patients were found to have a relatively low mean parasite density than patients with either blood group A or AB, but there was no significant difference in both cases (P=0.55 for O vs. A; P= 0.90 for O vs. AB) .The study revealed that on the basis of depressed hemoglobin concentration, patients with blood group O were less prone to severe P.falciparum malaria as compared to patients with blood groups A or B.
Abundance, Composition and Habitat Association of Rodents in Wonji Sugarcane Area; Ethiopia
(Addis Ababa University, 2006-06) Takele Serekebirhan; Bekele Afework (Professor); M.Balakrishnan (Professor)
A study on the ecology of rodents was carried out in Wonji Sugarcane Plantation from August 2005 to March 2006. Three trapping grids were randomly selected in the sugarcane plantation based on the growth stage of the cane as- immature sugarcane plant (ISP), young sugarcane plant (YSP), and old sugarcane plant (OSP). An additional grid was selected from bushland area outside the sugarcane plantation. A total of 629 captures were made in 2940 trap nights. Out of these, 557 individuals represented eight species of rodents: Mastomys natalensis, Arvicanthis dembeensis, Arvicanthis niloticus, Stenocephalemys albipes, Pelomys harringtoni, Mus mahomet, Mus musculus, and Rattus rattus. The remaining 72 individuals represented two insectivore species; Crocidura flavescence and Crocidura fumosa. Abundance of species varied in different growth stages of the sugarcane plantation and bushland area. There was seasonal difference in the abundance of the rodents. However, species composition was the same in all the three growth stages of the sugarcane plants and in bushland area. Variation in trap success with different growth stages of the of sugarcane plantations was significant. All age groups were represented in the population of most species. Breeding was seasonal for most of the species. The pest status of rodents in the sugarcane plantation was assessed. Analysis of the stomach contents of snap trapped rodents from the plantations showed sugarcane fibers that confirm the pest status of rodents in the sugarcane plantation while monocot plants were dominant in rodents captured from bushland area. Population estimation using minimum number alive (MNA) showed decline in each trapping session.
Acaia Byssinica Hochst. Exbenth: Pod and Seed Characteristics, Germination Physiology and Potentials for Seedling Establishment on Degraded Land
(Addis Ababa University, 1998-06) Haile, Berhank; Negash, Legesse (PhD)
This study was conducted on pod and seed characteristics, gel1ninalion physiology as well as the potentials of Acacia abyssinica Hochst. ex Benlll ssp. abyssinica fOI' growing on degraded land. Mature pods of A. abyssinica were collected ji'01/l Irees found in alld around Addis Ababa (wilhin a radius of 35 km). One hundred pods pel' tree were collected ji'on, 26 diJ)erellt frees. Comparison of the lIIeans of pod lenglh, pod widlh and seed nUlllber per pod showed Significant dij)erences (p < 0.05) among samples obtained ji'om the dij)erent localities. Pod lenglh, pod width and number of seeds per pod ranged between 3.7 and 14.4 cm, 1.0 and 2.7 CIII and 2 and 13 respeclively. 11lere was no significant correlation benveen pod lenglh and widlh. Pod lenglh and number of seeds per pod were significanlly correlated (p ~ O. OOO). On the other hand, pod widlh and number of seeds pel' pod were negalively cOI1'elaled (p ~ 0.000). Seeds collecled ji'om 35 dij)erent h'ees were made into 17 bulks (each containing 1000 seeds). 111e weight oflhe bulks ranged ji'om 74.01 to 116.11 g. There were significant dij)erences (p ~ O. OOO) among Ihe mean weights of the 17 seed bulks. E.Dects of gibberrelic acid (GA;I, indole-3-aceclic acid (lAA) and kinetin wilh concenh'alions ranging ji'01n 1IJ' M to 11J7 JIIi on percentage gennination and radicle length of chemically scarified seeds ofA. abyssinica were exall/ined None of Ihe plant growth regulators significantly increased Ihe total percenlage gel1l1ination of seeds as compared to the control. Gennination percentage decreased Significantly at higher concenh'ations of fAA (IIJ' ,vi and 10-' Ai) and kinetin (I (f' ill!). 1AA at 11J' }.i delayed genllination for aboul a week as compared to the other concenh'alions of the same, Ihough 63% of the seeds genllinated wilhin 10-15 days after incubalioll. GA, (at 11J' ill!) Significantly increased radicle length, while 1AA at 10-' 1'v1, 1IJ'M and 11J7 ivi significantly decreased the radicle length as call/pared 10 the confrol. The investigation on the potential of Ihe species for growing on degraded land involved the growing of seedlings (GA, 10-' }v1 h'eated and Ihe conh'ol) in plastic bags in Ihe greenhouse. Soil samples ji'Oln degraded land were collecled ji'om geomorphicolly different locations ji'om an area co 4 km' along Ihe road on Ihe l'vfodjo-Zeway road, at aboul 81 km soulh of Addis Ababa. Soil samples that served as a control were collected ji'01l/ places in and orollnd Addis Ababa where A. abyssinica is currently found growing. Gel1ninants ji'om 10-' JIIi GA, and the conh'ol were plan led in bolh types of soils and were left 10 grow in Ihe greenhouse fOI' 12 weeks. All the seedlings slllvived until ha/vest. Chemical and physical analyses of the soil samples were conducled in Ihe National Soils Laborato/y in Addis Ababa. The results of the analyses indicate that 10talnih'Ogen, organic carbon and available phosphorus were Significantly higher (p < O. 05) in the soils collecled ji'om places where A. abyssinica is cun'enlly grolVing than those ji'om Ihe deg/'Qded land On fhe other hand pH, No, K, Co, and CEC were found Significantly higher (p ~ 0.00) ill the soils collectedjimll degraded land The JIIeall vollies of plant height. IIIlmber ofbrallches. IIl1l1/ber of leaves. shoot dry weight alld root dry weight were fOlllld to be sigllificalltly higher ill the controls. FroJII the resllits. it cOllld be cOllelllded that: (I) the presellce of hard seed coats is the most ill/portallt factor inhibitillg gel7nillalioll ill seeds of A. abyssillica; (2) provided that seeds are carejilily scarified (chemically or mechanically), no gennination stimulators are required for obtaining maximum percentage germination; and (3) the slllvival (IIntii hmvesl) of the seedlillgs ill soils collected ji'om degraded lalld cOllld illdicate that A. abyssillica has the potelllials for growillg ill degraded land provided that the minimllm moistllre reqllirements of the species is met.
Acomparative Study on the Efficacy of Some Ethiopian Traditional Taenicides As Tested on the Earthworm
(Addis Ababa University, 1993-06) Gesare, Geraldine; Haile, Fisseha (PhD)
Intestinal parasitic infections represent serious medical and public health problems in many developing countries especially in the tropical regions. Taeniasis and cysticercosis have been recognized as important problems not only because of their impact on health but also because of economic losses resulting from condemnation of infected carcasses. The most frequently sold traditional medicines in Ethiopia are the taenicides. This is apparently due to the high prevalence of taeniasis in this country. Although a number of writers have mentioned a list of traditional taenicidal drugs in Ethiopia, very little serious work has been carried out to determine their relative efficacy. The present study is a contribution towards that end. TWelve traditional drugs used against human taeniasis in Ethiopia were screened for their taenicidal properties using the earthworm. The drugs were extracted using water and ethanol. The potency of the traditional drug extracts was compared with that of a commercial taeniacide, niclosamide. Results showed that Hagenia abyssinica (Kosso) is the most potent traditional taeniacide, followed by Glinus lotoides (Mettere), Albizia anthelmintica (Musenna), and, Myrsine africana (Ketchemo) in that order.
Adoptive Transfer of Lymphocytes and its Role in Protection against Schitosoma Mansoni Infection in Arvicanthus Species
(Addis Ababa,University, 1982-07) Mengestou, Seyoum; Belehu, Ayele (PhD)
Adoptive transfe r o f pr o t f!c tio n f rom i nf 'ctcd don or J.rvicanthus !.E. rats t o uninfec t ed r c cl pient~ was t!l ttt!mpted by va ~ y ing s omc pilram ~~b.! rs such a s the i ntl:ction pe riod o f donor r ats a nd the tine of tra ns f L; r r e l ati ve to c ha l ll.;nge . Concurre nt inve stigation o n t he e ffect of h~'~ r o l o g ous infec tion and fra ctio na tion o f c e ll s 11(l!:; ~lso carri(:d out. It wa s f ound tha t cPlls from 2 mo n th- lnfLctcd dono rs had high ability t o tra n s f c r r e sista ncl.! to rc:d,p i €..nt r ats while c el ls f r om 10 75 a nd 3 month- infL:ctcc' Jonor s s howed pa rtial a bi l ity and tho s e fr om 2 . 5 mo nth- infl:ctcd donors showed an une xpe cted inhi b i t ory e f fect on t ransfe r r e cipi e nts. Transfe rs d o ne c l o s e t o ch a ll L:ng~ nay c onfe r almo s t c omple t e i mmunity t o r e cipie nt rats , \0,:.':"_ Heterologous c e stode infe ction in t hes(! r-~ts appt:"!<'Ir t o play t!I s econdary r o l e in pro t ecting aguinst ,5 •• mansoni infe ctions, while it wa s a l so f ound t hat u nfr~Ltio n a t ed cells have mo r e ability t o tr n ~sf e r r c sis t~ n cc than fr actio na t ed ce lls . Po s s ible i~mun o l o gic a l me cha nisms involved dur i ng t hese e ve nts and the pr actica l s ignifica nce of thL: Hark arc briefly discuss ed .
Adoptive Transferor Lymphocytes And Its Role In Protecton Against Schist soma Manzoni Infection In Arvcicanthus Sp Rats
(Addis Ababa University, 1982-07) Nengestou, Seyoum; Belehu, Ayele (PhD)
adoptive transfer of protection from inducted donor acanthus !!l? rats to uninstructed recipients was attempted by va~yj.ng some parameters such as the inf8ction period of donor rats and the time of transfer relative to challenge. Concurrent investigation on the effect of.': 11ctorologous infection and fractionation of cells "idS also carried out. It ",as found that cells from 2 month .. ;.nf8ctcd donors had high ability to transfer resistance to recipient rats ) while cells f"om 1. 75 and 3 month-infected donors shO\.,ed partial abi Ii ty and those from 2.5 mont11",infected donors sho"led an unexpected inhibitory effect on transfer recipients. Transfers done close to challengu day confer almost complete immunity to recipient rCl"ts, \,:,.~, .. '" Heterologous cestode infection in these rc:ts appear to playa secondary role in protecting against Eo !~ansoni infections, ,.,hile it ",as also found that unfrilctionated cells have more ability to transfer resistance thul1 fractionated cells. Possible immunological mechanisms involvGd during these events ~nd the practical significance of the work are briefly discussed.
Aerobic Grm1--Negative Pharyngeal Bacilli of Adult Ethiopians: Carriage Rates and Antibiograms
(Addis Ababa University, 1985-10) Mengistu,Yohannes; Gedebou, Messele (Professor )
The study was conducted to identify the types of Gramnegative pharyngeal bacilli and to determine their prevalence and antibiotic susceptibilities. One~thousand pharyngeal sHab specimens were processed: 300 from students, 303 from adult employees of Berhanena-· Selam Printing Press (BSP), 200 from hospital staff and 197 from patients. The isolates were iden'tified by standard biochemical tests. All isolates were tested for their sensitivities to 11 antibietics using the Kirby-Bauer technique. Forty-five (15%) students, 53 (17.5%) employees of BSP, 27(13.5%) hospital staff and 54(27.4%) patients were carriers of one or more Gram-negative bacilli (GNB). The pharyngeal carriage rates of GNB were similar among the various groups of healthy subjects (P>O.l) but they were lower than that of the patients (peO.Ol). The increase in prevalence vIaS not correlated to antimicrobial therapy, but seems to be associated vlith underlying disease and duration of hospitalization. There was no association between isolation rates of GNB and age or sex. Two hundred and nineteen strains of more than 18 species of Enterobacteriaceae or nonfermenting Gram-negative bacilli were isolated. Colony counts of these organisms were lower among healthy subjects than among pa'tients. Klebsiella Vias most frequently ir;olated (37%), followed by _~seudo2!'-0Tl_a.? (13.2%), -E-n-te-r-o-b-a"ct-e-r (12.8%) and -A=c-i-n--e-t-o-b-a_c ... -t-e--r (10%). Others were less frequently isolated. The frequency of isolation of Klebsiell~ was higher from students (49%) than from the other three study groups (32.5%; P<0.05). The J)ol}rhospital isolates were more sensi ti ve than the hospital isolates. Over 70% of the nonhospital isolat*s were sensitive to 8 of the 11 antibiotics but 55%, 32% and 30% were sensitive to cephalothin, carbenicillin and ampicillin respectively. Over 74% of the hospital isolates were sensitive to':only polymyxin, gen-tamicin and trimethoprim<'sulphamethoxazole. About 59-64% of the hospital isolates were sensitive to chloramphenicol, kanamycin and sulphadiazine, while to the other antibiotics only below 33% were sensitive. Only 4.4% of nonhospital isolates were sensitive to all. A few strains showed intermediate susceptibilities to antibiotics. Nultiple antibiotic resistance Has higher among the hospital isolate (88.5%) than among the nonhospital isolates (59.6%; P
Aerobic Heterotrophic Bacterial Flor1ff one of Shalla Hot Springs
(Addis Ababa University, 1991-06) Kibret Mulugeta; Abegaz Berhanu (PhD)
Four sites in one of the hot springs of Shalla were selected for the study. The water from the sites merge to form a stream lqhich forms a temperature gradient. In this sttldy four' media were compared for the cuI ti vation and isolation of aerobic heterotrophic bacteria. The pH of the hot spring was 8.7 with a temperature of 96-560C. The formulated media were adjusted to pH values of 7.0-13.0. However,high counts of bacteria (lxl03-7xl01 cfu/ml) was only registered when the pH lqas adjusted between 8.0 and 9.0. A medium containing normal concentration of Trypton Soya Agar (TSA) was effective in supporting the growth of bacteria than a medium containing onequarter strength of TSA or supplement of tl'ace minerals. Replacing trace minerals ld th hot spring water improved the total number of bacteria growing and also the number of isolates. Thermophiles were numerous (lxl03-7xl01 cfu/ml) than thermotolerants (2xl02-2xlOI cfu/ml) at all si tes. The population of Bacillus brevis, Bacillus sphaericus, Bacillus stearothermophilus and Hicrococcus sp. was found to be low at lOlqer environmental temperatures than at higher environmental temperatures. In the course of this study a total of 44 microorganisms were isolated and characterized. Twenty nine were identified. to the species level and were found to be members of genus Bacillus. Three isolates were Gr~n-positive cocci identified to the genus level - Micrococcus. The remaining 12 isolates were either Gram-positive, filamentous or non-filamentous rods which need a detailed biochemical analysis for identification. To identify if any of the isolates may have industrial applications, they were checked for production of amylase and protease. Fifteen of the isolates produced protease, 18 amylase and eleven produced both amylase and protease.
Aerobic Heterotrophic Bacterial Flora of one of Shalla Hot Springs
(Addis Ababa,University, 1991-06) Kibret, Mulugeta; A. Gashe, Berhanu (PhD)
Four sites i n one ot the ho t.. springs ot Shalla were selec ted for the study. The wate r fr om t he sites me rge to form a s t ream whic h forms a te mperature gradient . In this study f our media we r e compa1;' ed tOI? the c ultivation and i solation o f aerobic heter otrophic bac ter i a. The pH of the ho t spring was 8. 7 with a temperature of 9G-56'C . The f o rmulated Illedia were adjusted to pH values o f 7 .0-13 .0. Howeve r , hlgh count s of bacte ria (lxlOl - 7x lOt c f u/ mll was only r egis tered when the pH was ad juste d be twee n 8.0 and 9.0. A medi um containing normal conce ntra tion of Trypton Soya Agar (TSA) was effective i n s uppo rt ing the growth of bacteria t han a med i um c on taining one quarte r strength of TSA o r supplement o f trace minerals. Replaci ng trac e minerals wi th hot s pri ng "" ate r improved the total numbe r of bacteria irowlng and also the number or i so l ates. Thcrmophl1ea were nume r o us (l:d Ol __ 1x l 0' clu/rol) than the rmo tol e r ants (2xlOl_2xl O( c fu/ml) at all sites . The population of Bac illus brevis , Bac illus spbae ricu8, Bacillus s t e arothermQphilu3 and Mi c r ococcus sp. was found to be low at l owe r e nvironmental temperatures than at hliher environmental temperatures . In t he course of t hi s s tudy a total of 44 micro organisms we r e isolated and char.cterlJ1ed. Twenty nine we r e identified to the s pecies level and were touftd to be membe r s o f genus Baci llus . Three isolates were Cram-positive cocci id e ntified t o the ge nus l eve l - Micrococcus. The r e main i ng 12 isolates were ei ther Gram-positi ve , filame ntous or no n- filamentous r od s wh ich need a deta il ed bioc he mi c al analysis for i denlifi c ation . To identify if any o f the isolates may have industrial applications , they we r e c hecked f o r product i on o f amylase and protease . Fifteen o f the isolates produced protease, 18 amylase and eleven I-roduced both amylase and protease.
Age and Growth of Oreochromis Niloticus (Pisces:Cichlidae) in Lake Hayq, Ethiopia
(Addis Ababa University, 1995-06) Alemu, Kebede; Tefera, Getachew (PhD); Admassu, Demeke (PhD)
otoliths from 447 mature and 308 immature Oreochromis niloticus (10 to 304 mm total length) from Lake Hayq were measured and examined for translucent and opaque macrozones. Microzone analysis was also conducted on the 308 immature O. niloticus otoliths. Macrozonal daily age estimate was determined by extrapolating the number of days between the date of capture and calender birth dates. utilization of the number of macrozones, condition on the edge of otoliths and date of capture enabled the separation of fish into recruitment groups. Microzones on the otoliths were enumerated and used as a measure of age in days and to hind cast hatch dates. The relationship between otolith size and fish total length 11as also examined. It appears that the breeding of o.niloticus in Lake Hayq is continuous with high peaks during !·larch-May and July-October. Two translucent macrozones '''ere formed per year during January-February and June-July. Fish spa~ned between January and May and July and November of the same year form the first translucent zone associated with biannuli at different times. The close agreement between macrozonal and microzonal daily age estimates (r=O. 84) sUbstantiates the usefulness macrozone analysis to assess the age of O.niloticus. There was a strong linear relationship between otolith size and fish size and also between microzone count and fish length. HOI-leVer, a linear relationship underestimates fish size at later ages. Values of size-at-age estimates obtained from macro zone and microzone analysis and fish total length-otolith radius relationship were close to each other. This demonstrates the usefulness of results from the latter method in supporting conclusions drawn from macrozone and microzone analysis.
Agro-Morphological and Molecular Characterization of Enset (Ensete Ventricosum (Welw.) Cheesman) Landraces from Ethiopia
(Addis Ababa University, 2018-06-01) Yemataw, Zerihun; Tesfaye, Kassahun (PhD)
The study was conducted with the objective of assessing and documenting indigenous knowledge and perception associated with the distribution, diversity, Enset Xanthomonas Wil, its etiology and mode of transmission, and management of enset in the country, and the genetic diversity of enset landraces that were obtained from different geograpHical locations in Ethiopia, using Phenotypic traits and to develop a genome sequence data, identify and develop single nucleotide polymorpHism (SNPs) and genotyping of landraces that serve as molecular markers for future marker assisted breeding. Enset genetic resource utilization and management study was conducted in eight ethnic groups in the Southern Nations, Nationalities and Peoples’ Regional State. The data was collected mainly through individual interviews and direct on-farm participatory monitoring and observation, key informant interviews. Relevant secondary data, literature and inter-personal data were collected from unpublished progress report from National Enset Research Project, elderly people and senior experts. Enset-based farming system is one of major agricultural systems in Ethiopia that serves as a backbone for at least one-forth of country’s population. Farmers used three morphological characters, two growth attributes, disease resistance and five use values traits in folk classification and characterization of enset. A total of 312 folk landraces have been identified. The number of landraces cultivated on individual farms ranged from one to twenty eight (mean of 8.08 ± 0.93). All ethnic groups in the study area use five use categories in order of importance: kocho yield and quality, bulla quality, amicho use, fiber quality and medicinal/ritual value. Of the 312 landraces 245 landraces having more than two use types. Management and maintenance of on-farm enset diversity is influenced by systematic propagation of the landraces, exchange of planting material and selective pressure. Farmers’ knowledge and perception of enset Xanthomonas wilt showed that a significant number of farmers are aware of EXW, its symptoms, etiology and transmission and spread, but they are not able to readily relate modes of spread to control methods. Since 2002, EXW became prominent in Hadiya, with the highest EXW incidence and severity, followed by Wolaita, and Kembata-Tembaro. Farmers identified EXW as the major cause for declining production and productivity of enset in the region. EXW has spread widely and rapidly in southern Ethiopia, with significant socioeconomic impacts in smallholders’ livelihoods. There is a need for developing knowledge-based strategies and awareness-raising campaign for EXW management. In general, the existing farmers’ knowledge on naming, classification and diversity should be complemented with maintenance of the creative dynamics of traditional knowledge and transmission of the knowledge are crucial for constructing sustainable management. Assessment of genetic diversity in enset using Phenotypic markers were subjected to ANOVA and the variations among the landraces and regions were significant (p ≤ 0.01) for all the 15 traits studied. Mean for plant height, central shoot weight before grating, and fermented squeezed kocho yield per hectare per year showed regional variation along an altitude gradient and xxiii across cultural differences related to the origin of the collection. Furthermore, there were significant correlations among most of the characters. This included the correlation among agronomic characteristics of primary interest in enset breeding such as plant height, pseudostem height, and fermented squeezed kocho yield per hectare per year. Altitude of the collection sites also significantly impacted the various characteristics studied. Cluster analysis grouped the landraces into five distinct groups, with two outlying landraces. Landraces originating from regions with similar agro-climatic conditions grouped together. Principal component analysis showed that the first four principal components accounted for ~74% of the total variance of the 387 enset landraces for the 15 quantitative traits studied. The linear discriminant analyses depicted about 40.8% (160 of the 387) and 45.2% (175 of 387) correct origin-based classification of the germplasm in terms of altitude zones and regions, respectively. Six qualitative morphological traits were also analyzed using the Shannon Weaver diversity index (H’).The Shannon-Weaver Diversity Index (H') for all sampled germplasm ranged from 0.50 to 0.89, with a mean of 0.73. Analysis of variance for H' revealed highly significant (p<0.01) differences among regions for all traits. Cluster analysis grouped the landraces into four clusters. A high proportion of landraces sourced from similar altitude classes and similar regions were grouped together. This indicated that there was wide variability among landraces studied. The Phenotypic differences in these 15 traits suggest significant degrees of genetic variation and that these traits can be exploited to identify potential donors for future enset improvement efforts. The implication of the current results for plant breeding, germplasm collection, and in situ and ex situ genetic resource conservation are discussed. Seventeen (for genome sequence analysis) and four hundred eighty (for SNP catalogue development) different enset landraces used were obtained from Areka Agricultural Research Center field germplasm. We present raw sequence reads and genome assemblies resulting from the sequencing of 17 landraces of the crop plant enset. Landraces having the same names but different origin showed different reads. For SNP detection, we considered only sites either homozygous or heterozygous for all 17 data sets. We were able to identify 33,200 singlenucleotide variant sites. We generated a series of phylogenetic trees and there was no sequence variation at this locus among the 17 genomes presented here. By examining the pattern of bands in agarose electrophoresis of the product after restriction digestion, it is possible to assess the genotype at that SNP location. We applied the 22 PCR-RFLP assays to single accession of E.ventricosum. Further, we then went on to apply 5 of these assays to several hundred E. ventricosum landraces. This findings will facilitate high-resolution studies to determine the genetic architecture of traits of economic and ecological importance, to study the structure of enset populations and to apply genomic selection in breeding programs. In general, farmers cognitive, morphological, sequence and SNP output clearly distinguished between all landraces, even though they were genetically similar.
Alkaline and Thermostable Xylanases of Potential Industrial Importance from Alkaliphiles
(Addis Ababa University, 1998-12) Gessesse, Amare; Mattiasson, Bo (Professor)
Three xylanase producing alkaliphilic bacterial strains designated AR-009, AR-135 and AR-22-1, were isolated from Lake Arenguadie, an alkaline soda lake in Ethiopia. AR- 009 and AR-135 were identified as strains of the genus Bacillus and Micrococcus, respectively, while AR-22-1 remains unidentified. The enzyme from all the 3 strains were purified following standard protein purification procedures, and the molecular weight of each enzyme was estimated using SDS-PAGE. Two xylanases designated as xylA and xylB, having molecular weights of 23 and 48 kD, respectively, were purified from the cell free culture supernatant of Bacillus sp. AR-009. XylA was optimally active at pH 9 while xylB showed optimum activity in the pH range of 9 to 10 and stable from pH 5 to 11. The optimum temperature for the activity of xylA was 70°C at pH 8 and 60°C at pH 9. On the other hand xylB was optiImilly active at 70°C at pH 8 and 75°C at pH 9. Both enzymes showed good stability at 60°C and at a pH of 8 and 9. AR-135 xylanase was optimally active at 55°C and a pH of 7.5 - 9.0. Over 60% of the maximum activity was displayed at pH 11. Its thermal stability above 40°C was very low. The optimum temperature and pH for the activity of AR-22-1 xylanase was 70°C and 8.0 to 9.5, respectively. The enzyme was stable in a broad pH range and showed good stability up to 60°C at pH 8 and 9 Agar immobilized cells of Bacillus sp. AR-009 were used for xylanase production with a view of finding cheap ways of enzyme production. In a batch culture maximum enzyme production was observed after 48 h and remained high up to 72 h. In repeated batch cultivation immobilized cells produced appreciable level of xylanase activity in 7 consecutive batches with out any significant decline in productivity. For continuous xylanase production immobilized cells were packed in a jacketed glass coluIlUl and sterile medium was continuously pumped. A stable continuous production of xylanase was observed over a period of one month. The volumetric productivity of the continuous culture was 17 fold higher than the batch culture using free cells. Another method of enzyme production investigated was the use of solid state fennentation. Bacillus sp. AR-009 produced high level of xylanase activity when grown using solid state fermentation (SSF) with wheat bran serving as a substrate. Xylanase production was highest at a wheat bran to moisture ratio of between 1:0.5 to 1: 1.5 and a Na2COJ concentration of 10% (w/w). No significant effect was observed on xylanase production when wheat bran is supplemented with peptone, try one, and yeast extract, thus avoiding the need to supplement wheat bran with expensive media. The ability of the organism to produce high titre xylanase activity at alkaline pH and lower wheat bran to moisture ratio could have a potential advantage in minimising the risk of contamination. In addition, because the enzyme can be extracted using minimum volume of liquid, the cost of down stream processing during product upgrading and the cost of waste treatment steps can be greatly reduced. The use of SSF for the production of xylanase by Bacillus sp. AR-009 could therefore lead to substantial reduction in the over all cost of enzyme production.
Alternative Technologies for Sustainable Agricultural Production and Agroecosystem Conservation in Arsi Highlands, Southeastern Ethiopia
(Addis Ababa University, 2010-07) Mengesha Berhanu; Asfaw Zemede (PhD); Kelbessa Ensermu (Professor))
Alternative technologies for sustainable agricultural production and ecosystem conservation study were conducted in Arsi Zone, Oromia Region. A total of 180 sample households were selected from 12 kebeles (smallest administrative unit in Ethiopia) of four weredas (districts). The households were stratified into rich, medium and poor wealth groups based on local criteria. Biophysical and socioeconomic data were collected using semi-structured interviews, Focus Group Discussions (FGDs) and interviews of key informants. Data on socioeconomics, agricultural crops and tree and shrub species were organized and analysed using computer software: SPSS, EXCEL and PAST. The diversity and composition of crop, tree and shrub species and agricultural crop production were characterized and the factors that affect their dynamics were identified. A total of 44 agricultural crop species were recorded of which Triticum aestivum, Hordeum vulgare, Eragrostis tef and Zea mays were the most common crops. In addition, a total of 90 tree and shrub species were recorded, among which, Juniperus procera, Olea europaea subsp. cuspidata, Podocarpus falcatus, Acacia tortilis, Acacia etbaica and Hagenia abyssinica were the main indigneous and multipurpose tree species. Eucalyptus globulus occurred in most of the farms (63%) and was the most important exotic tree species with highest relative values as fuelwood (35.6), construction (37.8), windbreak (22.2), income generation (30.0) and conservation (13.3). There were differences in averge annual incomes of the households among the rich (Birr 13,712), medium (Birr 9,148) and poor (Birr 5967) wealth groups. The main factors which were identified to create differences among the wealth groups were: landholding, family size, livestock resources, agricultural crop and tree and shrub species diversity and income sources in all weredas. The rich had more average landholding, number of livestock and use mix of x organic and inorganic fertilizers than the medium wealth group households and the medium wealth group had more average landholding, number of livestock and use mix of organic and inorganic fertilizers than the poor households. Thus, the uses of diversified and low agricultural inputs technologies have effect on the improvements of the livelihoods of the local communities. To ensure sustainable agricultural production and agroecosystem conservation, it is concluded that the country‘s educational, research and extension systems have much work ahead to support extension workers, farmers and policy makers in order to adequately deal with complex local farming systems that have co-evolved with human societies to fit local ecological conditions and satisfy human needs. Key words: Agroecological approach, biodiversity, diversification, ecosystem
Amebiasis in Ethiopia: Problems in diagnosis and determination of prevalence of infection
(2005-02) Kebede, Amra; Petros, Beyene(PhD)
Al though in thiopia int stin al am bias i is beli ved to b as ociat with many as of diarrhea, diagnos is is based on xamination of fre h stoo l sampl s b micros op)" a m thod that cannot discriminate the potential in asi e Entamoeba hi loly li a from th commensal Entamoeba dispar . The annual reports from Wonji Hospital and th Ethio- eth rlands AID Research Project indicate intes tinal am biasis to be a common infect ion \ ith the highest prevalence compared to other paras ites. Des pite a considerably high reporting of intes tin al amebias is, a twenty-year hospital reco rd among 117080 admitted pati nt showed on ly 47 suspected li ver abscess cases, suggesting overdiagnosis. Though the preval nce of E. hi loly lica/E. dispar by microscopy \ as 24.9 % in Wonji and Akaki, the speci.fic PCR did not confirm the pres nce of an E. hislolylica infection. E en after carefu l microscopic analysis, by using qu ali ty control meas ures on 246 pat ients with di arrhea, micro co p d monstrated 40 % pos iti ity of Entamoeba infection. Ho\ e er, appl ication of PCR, a mol cular diagnostic method that can distingu ish E. hi lolyli a [rom E. di par did not confi rm an E. hi loly li a. onl % harboured E.di par . Coproantigen detection ELI in th sam pati nts sho\ d clear lack of nsitivity and speciucit \ hereb onl 11 .4 % sp cim ns in th g nus ' nlamo ba p cific LI A \ r IJ1 agr m nt \ ith th P R. and non of th eight E. hi lo/y li a antig n po iti v as confirm d. Th ab nce or /'.,. hi 'lOlylica in ~ ction in onJI and kak i \ as b It r justiu d \ ith 10 \ r eropo iti it ( % findi ng. Ling r combinant surfac an tig n of '. hi IOlYli a. Furth r stud among h alth. primary-s hool tud nt and pn on r I~•. Ii par in lion. h 0 Ih ampl \\ Enlam ba inG lion, b ' ar ful ml ro py \\ ilh 0 ular m ur m nl, of G rm 1- Ih r on ntral . 0 \Vas th n 'Ira t d [rom th 21 s mpl 27.6% round Enlamo ba-p siti and run in a raj-lim P R \ ith primer , b d on th -r g n S qu n of E. hi '1OlYli a and E. di par , Ihal aJ lo\ 0 from th two sp I to be di tingui h d. lthough E. dispar 0 \ as id nti fi d in 19- 91. %), no E. hi lolyO a Dr \ as d I cled . This finding is con islen l \ ith the pre iou in stigation that rrk1I1y am bic inG ctions in Ethjopia are inco rrect I attribut d to E. hi {Oly liea and th n treated LIM c ssarl . In order to further confirm the actuaJ occurrence of E. hi IOlyli a, 110 susp ct d haematophagous trophozoites were co llected from diffe rent hospitaJs and heaJth center . Only three (2.7 %) E. hi 'LOlYliea cases \ ere detected by real-time PCR \ hil 71.3 % \ re 'f . dispar. The Gnding was similar among HIV / AIDS patients \ ith diarrh a ',: here microscop re ealed 12 % E. hi loly lieal£. di par, but none with E. hi •/oly liea. The trad.i tion of microscop in a routine diagnostic set-up appears unsatisfactory to rel.iabl differentiate RBCengulfing ameba from non-in vasi e ameba. The public health Lmplication of this study is that patient managem nt and alidity of epid emiological surveys are qu tionable as long as microscopy is the only diagnostic tool. There is also a need to continue \ ork to establish the aet iology of diarrhea wrongly associated with amebae and xplain th en.igma of patients recovering following ' anti-amebic' treatment. The commonl repo ned complaints of bloody mucoid di arrhea and association of 10\ D4 vith E. dispar infl ction among AID pat i nts r quir aJ t mati e explanation. Training in microscop n d impro m nl. if not to diagnose th inG clion aCC UJat I at lea t to minimize th 0 r-r porting. This \ ork emphasiz s th n c ssit of capacit building for important diarrh al patho::, n wi th m I cular diagno ti at reG rral levl
Amylase Production by Bacillus Species Isolated from Fermenting Tef and Kocho
(Addis Ababa University, 1993-06) Fikru Lealem; A.Gashe Berhanu (PhD)
Amylase producing bacterial strains associated with kocho and tef fermentation were isolated. The strain from fermenting kocho was identified as Bacillus subtilis while the strain from fermenting tef was identified as Bacillus licheniformis. Conditions for the productions of amylases were investigated. The bacterial strains secreted amylase into a liquid medium containing 1% soluble starch. When starch was replaced by disaccharide and monosaccharide, amylase production was reduced. Amylase production was higher with unfermented kocho compared to other native straches. Of the nitrogen sources tested, the greatest growth and amylase production were obtained with 0.5% peptone. The most appropriate metal salt for amylase production was found to be 0.02% MgS04. 7H20· Amylase was produced over a wide pH range (4.5 to 9.5 for Bacillus subtilis and 5 to 10 for Bacillus licheniformis with the maximum activity between pH 6 and 8. Amylase produci ton was greater at temperatures from 18 to 24 (room temperature) at 72 hour of cultivation. The amylases which were found to be extracellular were optimally active at 400 C and pH 5.6. Bacillus licheniformis T 31 amylase was also active at pH 8. The amylases of both organisms retained 100% activities for 1 hour at 60oC. These enzymes were stable in the pH range of 5.5-8.5. MgS04,CaC12 and BaC12 were found to stimulate amylase activity. The amylases were stable in 0.5 M NaCl with 64% -78% of their original activities being. retained after 24h. In addition to amylase, Bacillus subtilis also produced pullulanse. Using chromatographic analysis, glucose, maltose and maltotriose were detected as products of hydrolysis .
Analysis of Genetic Diversity Among Cultivated Enset (Ensete Ventricosum) Populations from Essera and Kefficho, Southwestern Part of Ethiopia Using Issr Marker
(Addis Ababa Universty, 2008-06) Chombe, Dagmawit
This study was conducted with the objective of investigation of genetic variation between populations of cultivated enset and provides information for conservation and improvement of enset. Leaf samples for seventy-one enset plants were collected from two areas of SW Ethiopia (Kefficho and Essera) and genomic DNA was extracted from the samples CTAB extraction method. Inter simple sequence repeats (ISSRs) as a molecular marker was used to assess genetic diversity both within and between populations using two ISSR primers (834 and 826). A total of 26 clear and reproducible bands were amplified from the two primers. Both UPGMA and neighbor joining trees were constructed for each individual and population using Jaccard’s similarity coefficient. The trees indicated two separate clusters which are based on the origin of populations and few intermixing of samples between regions was observed. The PCO analysis also recovered the UPGMA and neighbor joining trees groups. All parameters indicated that the clones of enset from Kefficho are more diverse than clones from Essera. Moreover, partioning of Shannon’s diversity index showed that the majority of the variations were observed within populations of enset than between the two populations. In conclusion, the present study using ISSR analysis, all the diversity parameters confirm that there is high diversity in cultivated Ensete ventricosum populations of SW Ethiopia and that ISSR markers can be successfully applied for the assessment of genetic diversity of this species. Therefore further research on analysis of genetic diversity of cultivated enset population including divergent production areas has to be done and the conservation capacity of institutes both for in-situ and ex-situ should be strengthen. Key Words: - Cultivated Ensete ventricosum, Essera, Ethiopia, Genetic Diversity, ISSR, Kefficho,
Analysis of the Genetic Diversity of Populations of Rana Angolensis Bocage 1866 Using the Issr Marker
(Addis Ababa University, 2008-06) Hailu Michael; Bekele Endashaw (Professor)
Four populations of the common river frog, Rana angolensis Bocage 1866, in the surroundings of Addis Ababa (Akaki, Entoto, Gulele and Kotebe), Ethiopia, were studied with the sample size of 10 for each. Inter Simple Sequence Repeats (ISSRs) as a molecular marker was used to assess genetic diversity, both within and between populations, using three di-nucleotide ISSR primers. A total of 29 clear and reproducible bands were amplified from the three ISSR primers. The over all gene diversity and percent polymorphisms were found to be higher in Akaki than in other populations (0.22). The Shannon-weaver diversity index also confirmed the existence of higher diversity in Akaki Rana populations than the other populations used in the present study. Furthermore, partitioning of the Shannon-weaver diversity showed that the majority of the variations were observed within populations of the Akaki and Entoto (68.89% and 55.17% respectively). Similarly, AMOVA demonstrate highly significant (P=0.00) genetic differences within each populations than among populations of Rana angolensis. Of the total variation, 27.25% was attributable to among populations, while 72.75% to within population variation. Both UPGMA and neighbour joining trees were constructed for each individual and population using Jaccard’s similarity coefficient. The trees do not clearly indicate the four distinct groups which are based on populations of area origin. The PCO analysis has also recovered the UPGMA and neighbour joining trees and each population do not appear to form a clear cluster. . Key words: genetic diversity, Rana angolensis populations, ISSR, Addis Ababa
The Application of the Enzyme Linked immunosorbent Assay (Elisa) In t'he Sehodiagnosis of Schistosoniasis
(Addis Ababa University, 1980-06) Taticheff, Seyoum; Melamed, M.D. (PhD)
A description of the schistosome parasite and its life cycle, its immunology and the fact that the parasite causes a disease of world-wide significance is made. The existing distribution of schistosomiasis in Ethiopia and its recorded vectors and the possibility that the disease may rapidly be coming a public health threat is mentioned. As possible tools for the sero-diagnosis of schistosomiasis, short accounts of the skin test, the indirect immuno-fluorescence test, the complement fixation test and the radio-immunoassay are gi ven. '['he enzyme linked immunosorben t assay (ELISA) as a promising diagnostic method has been elaborated '['he primary objective of this study was the assessement of ELISA as a sero-epidemiologic tool for schistosomiasis. In this study, samples from S .mansoni and- S .haematob.iill!! endemic areas and samples from non-endemic area were used. ~ljicroscopic examination of stool and/or urine ELISA on blood samples and skin tests for schistosomiasis were done. ELISA with a sensitivity of 86.86 to 96% and a specificity or 80 to 81% was preferred as a sero-diagnostic method for schistosomiasis from: the conventional microscopy where sensitivity was 101'1 and from the intradermal test which showed poor specifici ty (40% posi ti vi ty was observed in" non-endemi c area).
Asessment of Farmers’ Awareness and Adoption on Soil and Water Conservation Practices: the Case of Borebor Micro Watershed, Dera Woreda, Ethiopia
(Addis Ababa University, 2016-09) Erkie, Melkie; W., Bikila (PhD)
The Amhara regional state is highly affected by land degradation through soil erosion, to reverse the severity of the problem, soil and water conservation practice were introduced in different parts of the region including the study area. Even though a number of soil and water conservation methods were introduced to combat land degradation, adoption of these practices remains below expectation this research was conducted in bore bor micro water shed, Dera Woreda South Gondar Zone. It aimed to examine famers awareness on SWC activities, assess their adoption level on soil and water conservation activities and to examine the determinant factors of adoption. Structured questionnaire survey, field observation and focus group discussion method were applied to collect the necessary information from farm house holds for this a total of 107 house hold heads were involved during the study to collect the necessary information. The result showed that the majority of the respondent farmers participated in the SWC practise. Almost all sampled farmers have high awareness about problem of soil erosion on their farm land (91.6%).The majority of sampled farmers believed that soil erosion could be controlled with proper soil conservation measures. 89.7% of the farmers have adopted improved SWC structures such as stone bund &soil bund. One-way ANOVA indicated that there was significance differences between upper, middle and lower section of the water shed. Binary logistic regression model were used to analysis the important factors with regard to SWC the practices. It was found from the analysis that educational level, land security, extension contact, and soil and water conservation training Variables were found significant to affect adoption of soil and water conservation practice.Other variables like farm age, family size, labour availability, amount of livestock on the household, distance of the plot from the residence to home, and land holding were not significant relation to the adoption of improved SWC practice. KEY WORDS:-adoption, water shed, awareness, conservation, degradation, bore bor
Asexual Propagation of Juniperus Procera Hochst. Ex Endl. Through Rooting of Branch Cuttings
(Addis Ababa University, 1997-06) Berhe, Desta; Negash, Legesse (PhD)
The rooting responses of branch cuttings of Juniperus procera Hochst. ex Endl., obtained from juvenile and mature source plants to foul' plant growth regulators (PGRs), namely, indole-3-acetic acid (IAA), indole-3-butydc acid (lBA), naphthaleneacetic acid (NAA), and 2,4- dichlorophenoxyacetic acid (2,4-D) at vadous concentrations (lrrJ to lrr9 iW) were examined ill sand culture. Assessments 011 survival, callusing and rooting of the cuttings were conducted 16 and 32 weeks after the treatments. Odgin of root primordia was examilled microscopically, amI establishment and perfonnance of stecklil;gs were done 011 sample rooted cuttings. It was found that the developmental stage of the source plants from which the cuttings were derived, and the type, as well as the cOllcentratioll of the PGR, markedly affected the survival of the cuttings. About 77% of the cuttings obtained from Class 111 source plants (mature) died out withill the first 30 days after treatment; while 34% of the cuttings obtained from Class 11 (mature), and 90% of the cuttings obtained from Class I source plants (juvenile) survived until the end of the investigatioll. Callusing and rootillg of the cuttings were greatly affected by the developmental stages of the source plants. Sixteen weeks after treahnent, meall percentage callusillg of cuttillgs obtained from Class I source plants was significantly greater thall that obtailled from Class 11 source plants (p ,:; 0.05). The highest attainable percelltage of callused cuttings obtained from Class I source plants was 56, treated at 10-' 1'vlIAA and lrrs lW NAA. The corresponding percentage for the cuttillgs obtained from Class II source plants was 29, treated at 10-' M IBA. At this time, ollly 2% of the cuttings obtained from Class 1 source plants were rooted. Thirty two weeks after treatment, 24% of the cuttings obtained from Class 1 source plants were rooted. By this time, only a single cutting from Class II source plants rooted. The highest attainable percentages of rooted cuttings obtailled from Class I source plallts was 60 treated at 1 rr7 1'1'1 IAA. The cOlrespondillg percentages were 50, 44 and 25 for NAA (treated at 1rrJ J'rI), IBA (h'eated at lrrs 1'vI) alld 2,4-D (treated at 10-' and lrr7 M), respectively. The control resulted in 29% rooting. The melli/maximum attainable root numbers pel' rooted cuttings in IAA (treated at 10-' iW), IBA (h'eated at 1rr3 M), 2,4-D (treated at lrr9 M) and NAA (treated at lrrs i',I) were 17.0 ± 4.1, 14.5 ± 12.5, 9.7 ± 6.7 and 7.0 ± 3.0, respectively. The mean root number per rooted cuttings ill the conh'ol was 17.0 ± 1.7. The highest attainable mellll root length was 372 ± 51.5 mm, for cuttillgs treated at lrrJ M NAA. The correspollding values for IBA (h'eated at lrr3 M), IAA (treated at 10-' M) and 2,4-D (treated at 10-' M) were 113.7 ± 11.7mm, 90.7 ± 5.6 mm and 67.7 ± B.B 111m, respectively. The /IIean root length of the cuttillgs rooted ill the cOllh'ol was 93.9 ± 7.3 /11m. Regression analysis showed that the cOllflibution of callusing to rootillg is velY small (Rt = 0.2070, P ,:; 0.05). III this species, cells of callus tissue, xylem rays, trach~ids, c011ex alld cambium resulted ill the fonnatioll root primordia. Stecklings with well developed root systems were easily established and grew well, indicatillg the possibility of propagating the species by asexual means.

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