Journal of Agriculture and Ecology Research International

Aims: To determine condition status and identify parasitic fauna in intestine, gills and skins of Clarias gariepinus collected from two natural waters: Ogbese River (River A) (Longitude 5°26'E' and Latitude 6°43'N), and Owena River (River B) (Longitude 5.03E and Latitude 7.03N) in Ondo state, Nigeria respectively.

Study Design: Laboratory-experimental design was used in this study.

Place and Duration of Study: 120 live C. gariepinus African Mud Catfish were collected by the assistance of fishermen using cast net during the wet season during April to July 2016 from the two natural water bodies (Ogbese River and Owena River).

Methidology: Fish were transported live to the laboratory for examinations. Length (cm) and weight (g) measurement of fish were determined. Condition factor (K), isometric value (b) and regression coefficient were determined. Fish samples were examined using electronic Microscope (x 400 Mag.) by dissecting fish to remove organs (Intestines, gills and skins) for parasites occurrence (s). Descriptive and analytical statistics were used to analyse the data obtained.

Results: The condition factor for all C. gariepinus samples collected from both Rivers were less than one (<1), which indicated that the health status of the fish is biased, and the environment is not conducive. The parasitic examination carried out revealed that seventy-eight (65%) C. gariepinus fish samples were infested; while 42 (35%) of fish samples showed no parasite infestation. A total of Ninety-six (96) individual parasites were recovered from River A while a total of two hundred and twelve (212) individual parasites were recovered from River B. A total of eight (8) different parasites species were recovered while their percentage of occurrence was recorded. These include Ambiphrya spp. (4.17%), Camallanus spp. (6.25%; 2.83%), Capillaria spp. (16.98%), Chilodonella spp. (14.58%), Dactylogyrus spp. (64.58%; 5.66%), Diphyllobothrium latum (10.42%; 4.72%), Gyrodactylus spp. (61.32%) and Protoopalina symphysodonis (8.49%).

Conclusion: The water bodies need to be protected against further pollutants to prevent disease condition for the benefit of aquatic organisms and public health.

Biometrical evaluation is a valuable tool for the study of biosystematics of plant taxa. This study assessed morphological variation and phenetic relationship in the Cucurbitaceae species in Lafia, Nasarawa State, Nigeria. Plant specimens were collected by simple random sampling across the municipality and 11 species were identified in the study area. Analysis of variance and multivariate analyses were used to determine the differences and identify variation among morphological characters among the species, respectively. Genetic similarity among the taxa was generated by single linkage algorithm of Bray-Curtis similarity index. Wide variations were observed in the morphological characters; Telfairia occidentalis had the longest pods (46.3 cm) and the longest vines (831.4 cm), while Cucumis sativus had the shortest vines (162.3 cm). All the species had multi-seeded pods; Lagenaria breviflora had 734.7 seeds, which was significantly more than the seeds in other species, Citrullus lanatus had 438.3 seeds and Momordica charantia had the fewest seeds (12.7) per pod. T. occidentalis had significantly (p ≤ 0.05) the heaviest seeds (89.8 g) of the species. Three major clusters were identified; Lagenaria abyssinica and L. rufa had similarity index of 0.9; Cucumeropsis mannii and Citrullus lanatus had index of 0.89. Principal component analysis established close relationship between T. occidentalis and L siceraria; then L. breviflora, Citrullus lanatus; Cucumeropsis mannii, Cucurbita pepo, Cucumis sativus, Lagenaria rufa and Lagenaria abyssinica, Luffa cylindrica and Momordica charantia, indicative of genetic similarity among the taxa. Closely related species are potential materials for interspecific hybridization and improvement of the family.

Roots of orange-fleshed sweet potato varieties currently available in Nigeria contain high quantities of β-carotene or pro-vitamin A but have high moisture content. These varieties have been found to be a cheap and crucially important remedy for vitamin A deficiency. The cream or white-fleshed varieties, on the other hand, have a sweet taste with high dry matter content, giving a dry texture, a quality trait preferred in Nigeria. Development of sweet potato genotypes that can combine these two important quality traits is the objective of this breeding work. A diallel experiment using six parental sweet potato genotypes crossed in all possible combinations were carried out and thirty progenies were evaluated for beta carotene (β-carotene) and dry matter content in Landmark University, Omu Aran, Kwara State, Nigeria. The 30 F₁ progenies along with their parental lines were planted in the same field trial. The trial was laid out in 6 x 6 triple lattice in two replications. Highly significant (P≤ 0.01) differences were observed among the genotypes for the traits. The average β-carotene content among the progenies was 2.86 (mg/100g.f.w) while the dry matter cttgontent had a mean value of 31.89%. The cross progenies 199024.2 x Excel had the highest beta carotene (14.37mg/100g.f.w) content with the highest dry matter content (40.10%) and are therefore recommended for further evaluation.

Aim: The present study was aimed at elucidating the alternative metabolic preferences of Serratia sp. strain DW2 that permitted its survival in a diesel-contaminated environment.

Study Design: We adopted a 4 x 4 x 3 completely randomized design of a full-factorial experiment for the study.

Place and Duration of Study: The study was conducted at the Department of Microbiology, University of Calabar, Nigeria, during the months of March and June, 2019.

Methodology: In this study, Serratia sp. strain DW2 was isolated from Douglas Creek water of the Qua Iboe Estuary, along the Qua Iboe terminal at Ibeno, Nigeria, as a significant biological contributor to the decontamination process through inherent ability to utilize diesel oil hydrocarbons. This paper elucidated the growth and responses of the bacterial lipase, caseinase and gelatinase activities to diesel-oil hydrocarbon contamination.

Results: Range finding test results showed that the bacterium could grow in the presence of water soluble fraction of diesel (wsf-D) concentration between .0042 and .0335 µg/mL, albeit with increasing lag time and decreasing specific growth rate when compared with growth in glucose-Bushnell-Haas broth. Lag time changes were not significantly influenced by exposure time but changes in specific growth rate were. Gelatinase activity was most susceptible to toxicant onslaught but was least affected by exposure time. Conversely, lipase activity was the most affected by exposure time. Toxicant concentration/exposure time interaction of a two-way analysis of variance model for caseinase activity was not significant (P > .05) but those for lipase and gelatinase activities were.

Conclusion: The bacterium survived diesel toxicity by exploiting its lipase and gelatinase activities for provision of alternative sources of carbon, energy and nitrogen to drive ecosystem decontamination in the event of refined petroleum contamination.

Aims: The aim of this study was to establish the effect of selected soil amendments on Ralstonia solanacearum isolates in greenhouse on selected solaneceous crops.

Study Design:  The study was laid out as randomized complete block design (RCBD) in split pot arrangement for two seasons in the greenhouse.

Place and Duration of Study: The experiment was carried out in Kenyattta University situated in Kiambu County about 20 km from Nairobi city along Nairobi-Thika road between July, 2017- September, 2017 and between November, 2017- January, 2018.

Methodology: The three host crops of interest (potatoes, tomatoes and capsicum) were inoculated with prepared pure bacterial isolates; 18 (2T-Kiambu-Low Land), 71(2A-Nyeri-Low Land), 67 (2A-Nyeri-High Land), 83 (2T-Kirinyaga-Highland) and MX (18/71/67/83). Potatoes, tomatoes and capsicum were planted in pots each with a radius of 0.07 m (area 0.015 m²).The experiment had a total of 450 pots having a total area of 6.93 m². The treatments were Chalim^TM, Super-hydro-grow polymer + Metham sodium, Metham sodium, Metham sodium & Orange peel, Super-hydro-grow polymer, Brassica tissues, Chalim^TM + Super-hydro-grow polymer, Brassica tissue + Orange peel, Metham sodium + Super-hydro-grow polymer and Control (no amendments).

Results: There were significant differences (P≤0.05) in the bacterial wilt incidences in selected solaneceous crops between control and all the soil amendments used in season 1 and 2. Brassica tissue + Super-hydro-grow polymer was superior in reducing bacterial wilt incidences in selected solaneceous crops  in all the R. solanacearum isolates from Kenyan highlands and lowlands both in season 1 and 2.

Conclusion: Organic and inorganic soil amendments could serve as a viable control of bacterial wilt in solaneceous crops caused by R. solanacearum in the greenhouse.