Ethiopian Journal of Biological Sciences

Avian community assemblage and diversity in Chelekleka wetland, central Ethiopia

2024-02-27T04:51:06+00:00

Wetlands are one of the most bird-rich ecosystems on earth. However, they are also one of the systems that face human-induced threats. This study aimed at investigating the avian community assemblage and diversity of the highly degraded Chelekleka wetland, Ethiopia. Avian community diversity and composition in the wetland was investigated using vantage point and strip transect method. Data on post rainy, dry, pre rainy and rainy seasons were collected from November 2020 to October 2021 in four habitat types in and surrounding the wetland. A total of 24,653 individuals belonging to 246 species were identified. This wetland supported 11 Abyssinian endemic birds of which two were endemic to Ethiopia. Among bird species recorded in the wetland, 39% of them are either migrants and/or visitors to the area. Seasonally, 175, 193, 159 and 148 bird species were recorded during post rainy, dry, pre rainy and rainy seasons, respectively while 108 species were recorded in all seasons. A significantly high species abundance (17,523 individuals) and richness (193 species) were recorded during dry season, whereas highest diversity (H′ = 3.93) and evenness (E = 0.76) were observed during the post rainy season. Species diversity between habitats and seasons showed a significant difference. The seasonal community similarity among the four habitat types was significantly different. Chelekleka wetland is ecologically important in supporting high assemblage of resident, migratory as well as endemic bird species and hence an ideal location for ecotourism activities. However, anthropogenic threats such as farming, pollution, residential encroachment, wetland diversions and direct disturbances should be curtailed for sustainability of the wetland and its avian community.

Knowledge, attitudes, and practices of Metehara town community towards bat-borne diseases, central Ethiopia: A cross-sectional study

2024-02-27T05:28:49+00:00

This study assessed knowledge, attitudes, and practices of Metehara town community towards bat-borne diseases, where a novel coronavirus has recently been reported among cave bats in the area. A crosssectional study was carried out between April 2021 and June 2021 among randomly selected individuals in the community. Data were collected using structured questionnaires. Multivariable logistic regression analysis was used to assess associations between socio-demographic characteristics and overall knowledge of respondents about bat-borne diseases. Out of 392 study participants, the majority (88.5%, n=347) have heard that bats could transmit or serve as a source of disease to humans. Almost half of them (45.4%, n=179) heard this information from the Metehara’s community. About 40 (11.5%) of the participants perceived that bats could transmit rabies. Close to 26.3% (n=103) of the participants were found to have a high level of overall knowledge, 70.7% (n=277) favorable overall attitudes, and 98.7% (n=387) good overall practices towards bat-borne diseases. The overall knowledge about bat-borne diseases was strongly associated with observing wild animals in or around residents’ houses. The majority of the participants had high overall attitudes and practices about bat-borne diseases, but their overall knowledge level was low. Hence, there is a need to create community awareness regarding the risk of bat-borne diseases along with bat conservation.

Phytobeneficial properties of tomato (Lycopersicon esculentum L.) rhizospheric bacteria against bacterial wilt pathogen (Ralstonia solanacearum) under greenhouse conditions

2024-02-27T05:05:00+00:00

Bacterial wilt caused by Ralstonia solanacearum is the second most important pathogen causing bacterial wilt diseases in horticultural plants. In Ethiopia, the pathogen is widely distributed, affecting the production of tomatoes. This study was designed to isolate and characterize the pathogenicity of the local strains and study the potential antagonistic rhizobacteria (biological control agents) for potential control of the homologous pathogen using standard methods. All isolates displayed fluid and irregular colonies with pink or light red colours at the centre on the TTC medium typical features of R. solanacearum and showed a 60 to 96% wilting disease index percentage after 4 weeks of inoculation. The tomato varieties showed variation in disease resistance to the pathogen, with disease index ranging from 0.34 to 0.86, of which 30% of the tested tomato varieties such as the local Awash, Cochoro, Melkashola, and the commercial variety (Venise) were moderately resistant. Out of the 120 rhizobacteria isolates, 27 (23%) were antagonistic to the test pathogen and classified into their respective taxa based on their cultural and biochemical characteristics in relation to standard reference strains. Thus, the isolates were tentatively identified as Bacillus cereus, Bacillus pumilus, Bacillus subtilis, and Bacillus thuringiensis; Pseudomonas fluorescens, Pseudomonas putida, and Pseudomonas aeruginosa. The isolates were further characterized for additional plant growth promoting properties (PGPP). Most isolates were capable of producing hydrogen cyanide (88%), indole-3-acetic acid (IAA) (83%) (147–645 ug/ml), ammonia (76%); whereas 53% of the isolates solubilized inorganic calcium phosphate (280–471 ug/ml). The isolates Bacillus subtilis AAUB14, Bacillus pumilus AAUB13 andBacillus pumilus AAUB11 showed the highest number of PGPP as potential candidates for plant protection and health promotion provided that they are validated under greenhouse and field conditions.

Phenotypic properties of some acid tolerant Faba bean (Vicia faba L.) rhizobia from central highlands of Ethiopia

2024-02-27T05:11:01+00:00

The study aimed to assess phenotypic properties of some selected acid-tolerant faba bean rhizobia from central highlands of Ethiopia. Thirty soil cores were taken from 0–20 cm and composited for soil analysis following standard procedures. The plant trap method was used to isolate rhizobia. The purified colonies were used for eco-physiological, plant growth promotion (PGP) traits, and seed germination test. The soils were strongly (4.8) to moderately acidic (6.25) with no risk of salinity. Organic matter was 2.6–4.69%, whilst total nitrogen was 0.11–0.37% and the phosphorous availability was 12.88–63.97 cmolc/kg. The CEC was in the order of Ca>Mg>K>Na where micronutrients were Fe>Mn>Zn>Cu and wider. Forty acid-tolerant isolates were obtained from five faba bean fields (collected from Fiche, Ginci, Gudar, Holota, and Midakegn). Of these, 15 isolates which showed 100% tolerance to pH 4 to 5 were selected for other multiple PGP traits. Three rhizobial isolates (MFB5, FFB1, and MFB4) showed positive response for 8 PGP traits while FFB37 and GuFB8 which responded for 7 PGP traits were considered as the most potential in plant growth promoting properties. Rhizobial isolate FFB25 produced the highest indole-3-acetic acid (IAA) (174.63 ± 0.19 µg/ml) followed by MFB5 with 173.13 ± 0.14 µg/ml. Moreover, isolate FFB27 was known phosphate solubilizer (2 ± 0.025a) followed by MFB4 (1.7 ± 0.08ab) with the highest halo zone formation measured in mm. Isolate obtained from Fiche (FFB37) was best in seed germination assay with 118.67% followed by FFB1 (86%) and FFB25 (75%). There was a variation in % seed germination (72% and 56%) and vigor index (219.60 and 91.28) among inoculated and non-inoculated faba bean seeds separately. This study suggests the potential of these rhizobial isolates for inoculum development following greenhouse and field trials as soil acidity alleviation tools to boost supply of food and feed crops in the region.

Effects of single or mixed dietary supplementation of inulin or mannan-oligosaccharide (MOS) on growth, feed utilization, fatty acid profiles, gut morphology, and hematology in Nile tilapia fry

2024-02-27T05:18:55+00:00

The present study was designed to investigate the effect of supplementation of inulin and mannan-oligosaccharides (MOS), single or combined, on the growth performance, feed utilization, hematology, fatty acid profiles, and intestinal morphology of Chamo strain Nile tilapia Oreochromis niloticus (L.) fry. Nile tilapia fry (initial weight 1.37 ± 0.116 g) were fed four diets supplemented with prebiotics at 0 g of prebiotic/kg of fish feed (Diet-T1), 5 g kg^-1 inulin-supplemented diet (Diet-T2), 6 g kg^-1 MOSsupplemented diet (Diet-T3), or a combination of 2.5 g kg^-1 inulin and 3 g kg-1 MOS (Diet-T4). Each diet was randomly assigned to three aquaria and handfed 6% of their body weight divided into three portions daily. Fish fed 6 g kg1 of MOS had higher weight gain, Daily Growth Rate (DGR), Specific Growth Rate (SGR) and Feed Conversion Ratio (FCR) although the effect was not significant (p>0.05). Fish fed Diet-T3 and Diet-T4 had the highest content of polyunsaturated fatty acids (PUFAs). Fish fed Diet-T3 and Diet-T4 had significantly higher villi length in the proximal and middle portion of the intestine compared to other feeding groups. There was also significant difference (p<0.05) recorded in villus width in fish fed Diet-T3 and other feeding groups. Fish fed Diet-T3 also showed significantly higher goblet number at proximal and middle portion of the intestine. RBC, HCT, HGB neutrophil and monocyte levels were higher in the 6 g MOS kg-1 fed fish. MCHC, platelets, and eosinophil levels were higher in fish fed 5 g kg^-1 inulin supplemented diet. In conclusion, dietary supplementation of MOS could confer benefits on growth performance, fatty acid profiles, haematology, and intestinal morphology of Chamo strain Nile tilapia.