Variability of two populations of Cotesia flavipes and Chilo partellus was studied for reproductive success and developmental time under laboratory conditions. Fourth instar larvae of two populations of C. partellus (Ziway and Melkasa) were exposed to a day old mated adult female of two populations of C. flavipes (Ziway and Melkasa) to study the variability in reproductive success. The developmental time of the two geographical populations of C. flavipes reared on C. partellus obtained from the two different locations was also studied under four temperatures (20°C, 25°C, 28°C and 30°C). The experiments were designed in a complete randomized design. When both the parasitoid and the host were from the same location, the number of dead larvae inside the host and dead cocoons were significantly lower (p Keywords : Cotesia flavipes ; Chilo partellus ; Melkasa population; population interaction; Ziway population. Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 177-188
在实验室条件下，研究了黄绒螟和小腹螟两个种群的繁殖成功率和发育时间的变异。以两种褐皮螟(Ziway和Melkasa) 4龄幼虫与两种褐皮螟(Ziway和Melkasa) 1日龄的交配成虫接触，研究其繁殖成功率的差异。在20°C、25°C、28°C和30°C 4种温度条件下，研究了不同地点黄颡鱼种群的发育时间。实验采用完全随机设计。当寄主和寄生蜂来自同一地点时，寄主内死幼虫数和茧内死幼虫数显著低于寄生蜂(p)。紫椒;Melkasa人口;人口互动;Ziway人口。埃塞俄比亚生物科学杂志Vol. 5 (2) 2006: pp. 177-188
{"title":"Population Variability and Developmental Time Studies of Cotesia flavipes Cameron (Hymenoptera:Braconidae) Reared on Different Populations of Chilo partellus Swinhoe (Lepidoptera: Crambidae)","authors":"H. Abraha, E. Getu, E. Seyoum","doi":"10.4314/EJBS.V5I2.39035","DOIUrl":"https://doi.org/10.4314/EJBS.V5I2.39035","url":null,"abstract":"Variability of two populations of Cotesia flavipes and Chilo partellus was studied for reproductive success and developmental time under laboratory conditions. Fourth instar larvae of two populations of C. partellus (Ziway and Melkasa) were exposed to a day old mated adult female of two populations of C. flavipes (Ziway and Melkasa) to study the variability in reproductive success. The developmental time of the two geographical populations of C. flavipes reared on C. partellus obtained from the two different locations was also studied under four temperatures (20°C, 25°C, 28°C and 30°C). The experiments were designed in a complete randomized design. When both the parasitoid and the host were from the same location, the number of dead larvae inside the host and dead cocoons were significantly lower (p Keywords : Cotesia flavipes ; Chilo partellus ; Melkasa population; population interaction; Ziway population. Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 177-188","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125331599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microorganisms have been playing a pivotal role in the fermentation of human foods and beverages since the beginning of human civilisation. Fermented foods and beverages are defined as products obtained through desirable biochemical changes caused by the action of microorganisms or enzymes. In indigenous fermented foods, the microorganisms responsible for the fermentation are usually the microflora naturally present on the raw substrate. Fermentation is one of the oldest and most economical methods of producing and preserving food and is found to destroy undesirable components, to enhance the nutritive value, flavour and taste of the food, and to make the product safe from pathogenic microorgansisms. Fermented foods are produced world-wide using various manufacturing techniques, raw materials and microorganisms. However, there are only four main fermentation processes: alcoholic, lactic acid, acetic acid and alkali fermentation. Alcohol fermentation results in the production of ethanol, and yeasts are the predominant organisms (e.g. wines and beers). Lactic acid fermentation (e.g. fermented milks and cereals) is mainly carried out by lactic acid bacteria. Acetobacter convert alcohol to acetic acid in aerobic conditions as in the production of vinegar. Alkali fermentation is basically a proteolytic type and often takes place during the fermentation of fish and
{"title":"Review Article: A Review on the Microbiology of Indigenous Fermented Foods and Beverages of Ethiopia","authors":"M. Ashenafi","doi":"10.4314/EJBS.V5I2.39036","DOIUrl":"https://doi.org/10.4314/EJBS.V5I2.39036","url":null,"abstract":"Microorganisms have been playing a pivotal role in the fermentation of human foods and beverages since the beginning of human civilisation. Fermented foods and beverages are defined as products obtained through desirable biochemical changes caused by the action of microorganisms or enzymes. In indigenous fermented foods, the microorganisms responsible for the fermentation are usually the microflora naturally present on the raw substrate. Fermentation is one of the oldest and most economical methods of producing and preserving food and is found to destroy undesirable components, to enhance the nutritive value, flavour and taste of the food, and to make the product safe from pathogenic microorgansisms. Fermented foods are produced world-wide using various manufacturing techniques, raw materials and microorganisms. However, there are only four main fermentation processes: alcoholic, lactic acid, acetic acid and alkali fermentation. Alcohol fermentation results in the production of ethanol, and yeasts are the predominant organisms (e.g. wines and beers). Lactic acid fermentation (e.g. fermented milks and cereals) is mainly carried out by lactic acid bacteria. Acetobacter convert alcohol to acetic acid in aerobic conditions as in the production of vinegar. Alkali fermentation is basically a proteolytic type and often takes place during the fermentation of fish and","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123893680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Assefa, K. Urga, M. Guta, D. Melaku, W. Mekonen, M. Melesse, A. Senbeta, T. Kidanemariam
Solanum incanum L. (Solanaceae) is an annual herb that is used in the traditional medicine of Ethiopia for treating stomach and intestinal disorders. The spasmolytic activity of aqueous root extract of S. incanum was assessed on contractions of isolated guinea pig ileum, induced by acetylcholine, and compared with the effect of atropine. The aqueous root extract of S. incanum inhibited the response to acetylcholine in a concentration-dependent manner (EC= 0.215 mg/ml) similar to atropine which indicated that the extract is a relaxant of guinea pig isolated ileum. In addition to its antispasmodic activity in vitro , the extract inhibited charcoal travel in mice intestine by 36.28, 51.45, 52.93 and 38.53 percent in doses of 50, 100, 200 and 400 mg/kg body weight, respectively. As the inhibition of contractile activity of the ileum is the base of the treatment of some gastrointestinal disorders such as colic, S. incanum may have clinical benefits for treatment of these conditions. Phytochemical screening of the root of the plant revealed the presence of alkaloids, saponins, tannins and flavonoids. The50 alkaloids in the plant might be responsible for the anti-cholinergic activities observed. Results of acute toxicity study showed that the mice did not show any sign of conventional toxicity when administered doses of up to 15,000 mg/kg body weight orally. Keywords : Anti-spasmodic; Crude extract; Solanum incanum . Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 137-146
{"title":"Spasmolytic Activity of the Aqueous Root Extract of Solanum incanum , Solanaceae","authors":"A. Assefa, K. Urga, M. Guta, D. Melaku, W. Mekonen, M. Melesse, A. Senbeta, T. Kidanemariam","doi":"10.4314/EJBS.V5I2.39032","DOIUrl":"https://doi.org/10.4314/EJBS.V5I2.39032","url":null,"abstract":"Solanum incanum L. (Solanaceae) is an annual herb that is used in the traditional medicine of Ethiopia for treating stomach and intestinal disorders. The spasmolytic activity of aqueous root extract of S. incanum was assessed on contractions of isolated guinea pig ileum, induced by acetylcholine, and compared with the effect of atropine. The aqueous root extract of S. incanum inhibited the response to acetylcholine in a concentration-dependent manner (EC= 0.215 mg/ml) similar to atropine which indicated that the extract is a relaxant of guinea pig isolated ileum. In addition to its antispasmodic activity in vitro , the extract inhibited charcoal travel in mice intestine by 36.28, 51.45, 52.93 and 38.53 percent in doses of 50, 100, 200 and 400 mg/kg body weight, respectively. As the inhibition of contractile activity of the ileum is the base of the treatment of some gastrointestinal disorders such as colic, S. incanum may have clinical benefits for treatment of these conditions. Phytochemical screening of the root of the plant revealed the presence of alkaloids, saponins, tannins and flavonoids. The50 alkaloids in the plant might be responsible for the anti-cholinergic activities observed. Results of acute toxicity study showed that the mice did not show any sign of conventional toxicity when administered doses of up to 15,000 mg/kg body weight orally. Keywords : Anti-spasmodic; Crude extract; Solanum incanum . Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 137-146","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121662285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Bayo, N. Rethman, P. Hammes, C. V. D. Merwe, J. Grimbeek, M. V. D. Linde
An experiment was conducted in growth chambers to study the response of sorghum cultivars to water deficit stress. Seven sorghum cultivars were evaluated under three water deficit levels [control (-0.05 MPa), mild stress (-0.27 MPa), and severe stress (-0.96 MPa)] in a hydroponic culture in a completely randomised block design replicated three times. The three water deficit levels were created by adding 0, 10 and 20% (w/v) polyethylene glycol 6000 (PEG 6000) to the nutrient solution. The results indicated that water deficit, especially severe water deficit (-0.96 MPa), severely affected the growth and physiology of sorghum. Water deficit stress reduced plant height, leaf area, dry matter accumulation, water use efficiency, root length, and stomatal density. Water deficit stress increased stomatal closure and thus leaf diffusive resistance. Stressed plants deposited larger amounts of epicuticular wax on leaf surfaces and stomatal openings. Water stress significantly reduced the amount of starch grains in the chloroplasts. Sorghum cultivars displayed distinctive response to water deficit stress for many of the parameters. Jigurti, Gambella 1107 and Meko grew better than P9403 and SA1486 under water deficit conditions. Jigurti showed no significant reduction in any of the growth parameters even under severe water deficit (-0.96 MPa) conditions. Keywords : Epicuticular wax; Leaf diffusive resistance; Leaf relative water content; Starch; Stomata; Water use efficiency. Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 161-176
{"title":"Effect of Water Deficit Stress on the Physiology, Growth and Leaf Cell Ultrastructure of Sorghum ( Sorghum bicolor r (L.) Moench)","authors":"W. Bayo, N. Rethman, P. Hammes, C. V. D. Merwe, J. Grimbeek, M. V. D. Linde","doi":"10.4314/EJBS.V5I2.39034","DOIUrl":"https://doi.org/10.4314/EJBS.V5I2.39034","url":null,"abstract":"An experiment was conducted in growth chambers to study the response of sorghum cultivars to water deficit stress. Seven sorghum cultivars were evaluated under three water deficit levels [control (-0.05 MPa), mild stress (-0.27 MPa), and severe stress (-0.96 MPa)] in a hydroponic culture in a completely randomised block design replicated three times. The three water deficit levels were created by adding 0, 10 and 20% (w/v) polyethylene glycol 6000 (PEG 6000) to the nutrient solution. The results indicated that water deficit, especially severe water deficit (-0.96 MPa), severely affected the growth and physiology of sorghum. Water deficit stress reduced plant height, leaf area, dry matter accumulation, water use efficiency, root length, and stomatal density. Water deficit stress increased stomatal closure and thus leaf diffusive resistance. Stressed plants deposited larger amounts of epicuticular wax on leaf surfaces and stomatal openings. Water stress significantly reduced the amount of starch grains in the chloroplasts. Sorghum cultivars displayed distinctive response to water deficit stress for many of the parameters. Jigurti, Gambella 1107 and Meko grew better than P9403 and SA1486 under water deficit conditions. Jigurti showed no significant reduction in any of the growth parameters even under severe water deficit (-0.96 MPa) conditions. Keywords : Epicuticular wax; Leaf diffusive resistance; Leaf relative water content; Starch; Stomata; Water use efficiency. Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 161-176","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116932594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Among the overlooked major causes in Ethiopia that led to the destruction of forests, inappropriate utilization and endangering of the valuable tree species such as Hagenia abyssinica are lack of technical information on basic properties of wood and its utilization methods. The objective of this study was, therefore, to determine the basic physical and mechanical properties of H. abyssinica at green and dry conditions, their interactions and effect on its timber utilization. The study showed that there was significant difference (p Keywords : Density; Hagenia abyssinica; Mechanical properties; Moisture content; Seasoning of wood; Uses. Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 117-135
在埃塞俄比亚，导致森林遭到破坏、不适当利用和危及珍贵树种(如深海赤杨)的主要原因被忽视，其中一个原因是缺乏关于木材基本特性及其利用方法的技术资料。因此，本研究的目的是确定绿色和干燥条件下深海青杉木的基本物理和机械特性，它们之间的相互作用及其对木材利用的影响。研究表明，两种植物间存在显著性差异(p)。Hagenia abyssinica;机械性能;水分含量;木材的调味剂;用途。埃塞俄比亚生物科学杂志Vol. 5 (2) 2006: pp. 117-135
{"title":"Some Basic Physical And Mechanical Properties Of The Valuable Hagenia abyssinica Timber And Their Interactions: Imlpication For Its Rational Utilization","authors":"G. Desalegn","doi":"10.4314/EJBS.V5I2.39031","DOIUrl":"https://doi.org/10.4314/EJBS.V5I2.39031","url":null,"abstract":"Among the overlooked major causes in Ethiopia that led to the destruction of forests, inappropriate utilization and endangering of the valuable tree species such as Hagenia abyssinica are lack of technical information on basic properties of wood and its utilization methods. The objective of this study was, therefore, to determine the basic physical and mechanical properties of H. abyssinica at green and dry conditions, their interactions and effect on its timber utilization. The study showed that there was significant difference (p Keywords : Density; Hagenia abyssinica; Mechanical properties; Moisture content; Seasoning of wood; Uses. Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 117-135","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132267693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aphanizomenon flos-aquae Ralfs ex Born. and Flah. var. flos- aquae (Cyanobacteria) was sampled from Upper Klamath lake and subjected to batch culture of 15-litre bioreactors. Growth characteristics viz. doubling time (Dt), specific growth rate (µ), temperature requirement, biomass and chlorophyll-a concentrations were studied during exponential growth phase at a fixed light intensity of 40-45 micromole in a CT medium. CT growth medium when supported by CO2 from a chemical byproduct in a connected chemical reactor resulted in better growth characteristic than either ASM or ASM-1 in literature. A relationship of dry weight (dw) and absorbance of the culture in CT medium was developed for calculations without the absolute need of the time-consuming dry weight measurements. Maximum measured dry weight obtained at this growth condition after 120 hours is 151 g/m 3 . The best growth temperature studied in this work is 20 o C with a supply of CO2. Results are compared with previous findings in the literature and recommendations are made for mass cultivation.
{"title":"MASS CULTURE OF APHANIZOMENON FLOS-AQUAE RALFS EX BORN. AND FLAH. VAR. FLOS-AQUAE (CYANOBACTERIA) FROM KLAMATH FALLS, OREGON, USA, IN CLOSED CHAMBER BIOREACTORS.","authors":"H. Debella","doi":"10.4314/EJBS.V4I2.39019","DOIUrl":"https://doi.org/10.4314/EJBS.V4I2.39019","url":null,"abstract":"Aphanizomenon flos-aquae Ralfs ex Born. and Flah. var. flos- aquae (Cyanobacteria) was sampled from Upper Klamath lake and subjected to batch culture of 15-litre bioreactors. Growth characteristics viz. doubling time (Dt), specific growth rate (µ), temperature requirement, biomass and chlorophyll-a concentrations were studied during exponential growth phase at a fixed light intensity of 40-45 micromole in a CT medium. CT growth medium when supported by CO2 from a chemical byproduct in a connected chemical reactor resulted in better growth characteristic than either ASM or ASM-1 in literature. A relationship of dry weight (dw) and absorbance of the culture in CT medium was developed for calculations without the absolute need of the time-consuming dry weight measurements. Maximum measured dry weight obtained at this growth condition after 120 hours is 151 g/m 3 . The best growth temperature studied in this work is 20 o C with a supply of CO2. Results are compared with previous findings in the literature and recommendations are made for mass cultivation.","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"37 13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132893674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Interactions between common rust, uromyces appendiculatus , and fusarium wilt, fusarium oxusporum f.sp. phaseoli , on common beans","authors":"B. Admassu, B. Hau","doi":"10.4314/EJBS.V5I1.39028","DOIUrl":"https://doi.org/10.4314/EJBS.V5I1.39028","url":null,"abstract":"","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114764221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"In-situ (on-farm) conservation dynamics and the patterns of uses of sorgham ( Sorghum bicolar (L.) Moech landraces in North Shewa and South Welo, Ethiopia","authors":"A. Abdi, Zemede Asfaw Z. Asfaw","doi":"10.4314/EJBS.V4I2.39021","DOIUrl":"https://doi.org/10.4314/EJBS.V4I2.39021","url":null,"abstract":"","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121698516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A new species of commiphora (Burseraceae) from Ethiopia","authors":"T. Soromessa","doi":"10.4314/EJBS.V5I1.39025","DOIUrl":"https://doi.org/10.4314/EJBS.V5I1.39025","url":null,"abstract":"","PeriodicalId":187522,"journal":{"name":"Ethiopian Journal of Biological Sciences","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126150766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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