Variability and Heritability of Yield and Yield Components of Various Rice (Oryza sativa L.) Varieties in Port Harcourt, Nigeria

Field experiments were conducted at the Rivers State University Teaching and Research Farm Nkpolu, Port Harcourt, during the 2019 planting season under rainfed condition and complimented by irrigation in two different planting dates to access the genetic variability and heritability in yield and yield components of twenty-five rice varieties. The experiments were laid out in a randomized complete block design with three replications. Data were collected on eleven yield and yield components. Results from the analysis of variance indicated significant differences (P < 0.01 < 0.05) among the varieties for all parameters except plant height and tiller number in planting date one. Combined analysis of variance across planting dates showed that there was significant variation (P < 0.01) among the rice varieties for all parameters evaluated. The varietal mean performance for phenological parameters showed significant differences (P < 0.05) for all parameters except tiller number in planting date one. Variability evaluation of varieties for yield parameters showed significant differences (P < 0.05) for all parameters evaluated except for 100-grain weight in planting date two. The pooled mean values of the varieties differed significantly (P < 0.05) for all yield parameters evaluated. The highest grain yield per stand was recorded in UPIA 2 with 7.41 g/stand, and was significantly different from FARO 67 with the least (1.70 g/stand). The estimate of variance components showed that phenotypic variance (Vp) and phenotypic coefficient of variation (PVC) were higher than their corresponding genotypic variance (Vg) and genotypic coefficient of variation (GCV) for all the parameters studied. Heritability estimates in broad sense were found to be moderate for majority of the parameters, except leaf area (68.12%), panicle number (63.41%), spikelet fertility (50.23%) and grain yield per stand (55.87%) that had high heritability estimates and tiller number (15.93%) which had a low estimate. However, only leaf area, panicle number and grain yield per stand had high heritability estimates which were accompanied by high genetic advance. There was considerable variation among the 25 rice varieties evaluated. UPIA 2 and FARO 44 had the best agronomic performance. However, UPN 324, UPN 228, FARO 61 and 66 could be selected for onward improvement programme. Keynote: Grain yield, heritability, Oryza sativa, variation, yield components DOI: 10.7176/ALST/86-04 Publication date:March 31st 202

Effect of Ethanoic Extract of Treculia Africana Seeds on Total Cholesterol, Total Protein, and Nitric Oxide

Treculia africana is well known and eaten by the people of South-South and South-East region of Nigeria. T. africana can be eaten alone or process and combine it with other fruits. It is nutritious and provide natural bioactive substance to the body. This study was aim to evaluate the Effect of Ethanoic Extract of Treculia africana Seeds on Total Cholesterol, Total Protein, and Nitric Oxide. It was an experimental research. 20 male rats were randomly selected into four groups (control, low dose, moderate dose and high dose groups) with five animals per group.  Group A served as control and received only water and pellet feed, Group B (low dose) received 250mg/kg, group C (moderate dose) received 300mg/kgand group D (high dose) received 350mg/kg of aqueous extract of Treculia africana seed respectively. The extract was administered orally to the rats once a day for a period of 10days. On the 11th day, the animals were anaesthetized with chloroform soaked in cotton wool and blood tissues were collected. The results revealed that,there is significantly increase in the serum levels of total protein in all the treated groups when compared with control (Total protein control 51.40±0.51, low dose 61.60±0.51* medium dose 71.60±0.51*, and 71.80±1.07*). Total cholesterol significantly decreased when both medium and high dose were administered when compared with control (Total cholesterol control 2.34±0.05, medium dose 1.90±0.07*, high dose 1.96±0.19*). Also, nitric oxide significantly increases serum levels in the groups treated with T. africana when compared with control (Nitric oxide control 7.16±0.14, low dose 8.98±0.09*, medium dose 8.50±0.15* and high dose 8.02±0.11*)

Hepatotoxic Effects of Potassium Bromate on Adult Wistar Rats

Objective: We aimed to demonstrate the histopathologic effects of potassium bromate (KBrO3) on the liver cells of rats following oral administration. Method: Twenty young Wistar rats of weights 196-215g were divided into four groups. The control group A was orally administered with 1ml of distilled water daily; the experimental groups B, C and D were orally administered with 50, 100, and 200 mg/kg body weight/day dosages of KBrO3 for 35 days. Both the control and experimental groups were sacrificed using the chloroform inhalation method at the end of study period.Results: Rats which received 200 mg kg-1 b.wt. of KBrO3 died within the 20th day of administration. The body weights were significantly increased (P<0.05) in the experimental groups from the 3rd to the 5th week of study while the relative weight of their liver were not affected compared to the control group. Histopathological examination of the experimental groups indicated; little sinusoidal dilatation in rats treated with 50 mg kg-1 b.wt. of KBrO3; hepatic vacuolation, large sinusoidal dilatation, degenerative changes and cellular congestion in rats, which received 100, 200 mg kg-1 b.wt. of KBrO3 compared with the control group, which maintained normal kidney tissues. These histological alterations appeared marked in rats administered with 200 mg kg-1 b.wt. of KBrO3.Conclusion: The present study indicated dose-dependent, histopathologic effects on the liver cells of rats administered with KBrO3. Our findings therefore suggest that chronic KBrO3 consumption may put the liver at some risk of adverse histopathological conditions. Keywords: Liver, histopathology, potassium bromate, hepatotoxicity

Splenotoxic effect of radiographic developer effluent on Wistar rats

Background: Histological changes associated with toxicity of radiographic developer effluents on spleen tissues have not been previously studied. The present study therefore aimed at demonstrating the histopathological changes in splenic tissues of Wistar rats following exposure to developer effluent.Methods: Eighteen young Wistar rats weighing 140-220g were used for the study. The animals were divided randomly into three groups of 6 rats each based on the dose of developer effluent administered to them – i.e. control group I (0 dose) and experimental groups II (lower dose, 200 mg/kg) and III (higher dose, 400 mg/kg) respectively. The groups were further classified as either A or B sub-groups of three rats each, depending on the duration (14 or 28 days) of effluent administration. The effluent administration was done by oral gavages.Results: Normal spleen histology was observed in the control group. In contrast, tissue degeneration and necrosis; lymphocytic infiltration as well as reduction of splenic follicles were observed in some of the test groups (IIA, IIB and IIIA). Interestingly, the toxic effects of the developer effluent on group IIIB administered with higher dose for a longer period of 28 days were not as severe as observed in the other test groups.Conclusions: The present study which indicated adverse effects of exposures to sub-lethal doses of developer effluent on Wistar rats’ spleen tissues suggests the need for proper management and disposal of radiographic effluents.

Ascertaining the Overall Occurrence of Dental Fluorosis in Students of Selected Secondary Schools in Rivers State

Public health places a premium on understanding the amount of fluoride in potable water and other toothpastes, as well as how it affects skeletal and dental tissues to cause fluorosis. Fluorosis is, however, poorly understood and known in Nigeria. The goal of this research was to Ascertain the Overall Occurrence of Dental Fluorosis in Students of Selected Secondary Schools in Rivers State. A cross-sectional survey of 541 students from selected secondary schools in Rivers State who were between the ages of 9 and 17 was carried out. All students present at school on the day of data collection had their mouths examined by oral health professionals as part of a quasi-experimental method. Each subject was supported by a torch light while seated on a chair, and their teeth were examined for dental fluorosis in their wet state. The presence of dental fluorosis and the severity of it were documented using Dean's Dental Fluorosis. The presence of dental fluorosis and the severity of it were documented using Dean's Dental Fluorosis. (358) Dental fluorosis impacted 66.17% of the students, varying in severity from very mild to severe cases

Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities

Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil) both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities

Interaction of Copper-Based Nanoparticles to Soil, Terrestrial, and Aquatic Systems: Critical Review of the State of the Science and Future Perspectives

In the past two decades, increased production and usage of metallic nanoparticles (NPs) has inevitably increased their discharge into the different compartments of the environment, which ultimately paved the way for their uptake and accumulation in various trophic levels of the food chain. Due to these issues, several questions have been raised on the usage of NPs in everyday life and has become a matter of public health concern. Among the metallic NPs, Cu-based NPs have gained popularity due to their cost-effectiveness and multifarious promising uses. Several studies in the past represented the phytotoxicity of Cu-based NPs on plants. However, comprehensive knowledge is still lacking. Additionally, the impact of Cu-based NPs on soil organisms such as agriculturally important microbes, fungi, mycorrhiza, nematode, and earthworms are poorly studied. This review article critically analyses the literature data to achieve a more comprehensive knowledge on the toxicological profile of Cu-based NPs and increase our understanding of the effects of Cu-based NPs on aquatic and terrestrial plants as well as on soil microbial communities. The underlying mechanism of biotransformation of Cu-based NPs and the process of their penetration into plants has also been discussed herein. Overall, this review could provide valuable information to design rules and regulations for the safe disposal of Cu-based NPs into a sustainable environment

Character Association of Yield and Yield Components of Various Varieties of Rice (Oryza sativa L.)

Yield and yield attributing parameters are the most widely targeted traits in rice improvement programmes. The relationship between yield and yield attributing traits are important for direct and indirect selection of traits which contribute to yield. Information on the extent of association between yield and yield components is important in the simultaneous improvement of correlated traits. This study was carried out to determine the direct and indirect contributions of yield components to yield of rice and the level of association. Path Coefficient Analysis was used to evaluate the character association of yield and yield components of twenty-five rice varieties at the Rivers State University Teaching and Research Farm, Port Harcourt, during the 2019 planting season under rainfed condition and complimented by irrigation in two different planting dates. The experiments were laid out in a randomized complete block design. Data were collected on yield and yield components. Leaf area, plant height, panicle length, panicle number, panicle weight, 100-grain weight and spikelet fertility correlated positively and significantly with grain yield per stand. The path coefficient analysis indicated that panicle number (0.265) and spikelet fertility (0.219) had the highest positive direct effect on grain yield per stand. Conversely, number of grains per panicle (-0.128), days to 50% flowering (-0.114), tiller number (-0.095) and panicle length (-0.056) exerted negative direct effect on grain yield per stand with 0.674 residual effects. Therefore, direct selection for leaf area, plant height, panicle number, panicle weight, 100 grain weight, and spikelet fertility will effectively improve yield in rice. Keywords: Grain yield, Character Association, Oryza sativa, variation, yield components DOI: 10.7176/JNSR/13-8-02 Publication date: April 30th 202

Nano-CuO and interaction with nano-ZnO or soil bacterium provide evidence for the interference of nanoparticles in metal nutrition of plants

The expansion of nanotechnology raises concerns about the consequences of nanomaterials in plants. Here, the effects of nanoparticles (NPs; 100–500 mg/kg) on processes related to micronutrient accumulation were evaluated in bean (Phaseolus vulgaris) exposed to CuO NPs, a mixture of CuO and ZnO (CuO:ZnO) NPs, and in CuO NP-exposed plants colonized by a root bacterium, Pseudomonas chlororaphis O6 (PcO6) in a sand matrix for 7 days. Depending on exposure levels, the inhibition of growth by CuO NPs was more apparent in roots (10–66 %) than shoots (9–25 %). In contrast, CuO:ZnO NPs or root colonization with PcO6 partially mitigated growth inhibition. At 500 mg/kg exposure, CuO NPs increased soluble Cu in the growth matrix by 23-fold, relative to the control, while CuO:ZnO NPs increased soluble Cu (26-fold), Zn (127-fold) and Ca (4.5-fold), but reduced levels of Fe (0.8-fold) and Mn (0.75-fold). Shoot accumulations of Cu (3.8-fold) and Na (1-fold) increased, while those of Fe (0.4-fold), Mn (0.2-fold), Zn (0.5-fold) and Ca (0.5-fold) were reduced with CuO NP (500 mg/kg) exposure. CuO:ZnO NPs also increased shoot Cu, Zn and Na levels, while decreasing that of Fe, Mn, Ca and Mg. Root colonization reduced shoot uptake of Cu and Na, 15 and 24 %, respectively. CuO NPs inhibited ferric reductase (up to 49 %) but stimulated cupric (up to 273 %) reductase activity; while CuO:ZnO NPs or root colonization by PcO6 altered levels of ferric, but not copper reductase activity, relative to CuO NPs. Cu ions at the level released from the NPs did not duplicate these effects. Our findings demonstrate that in addition to the apparent phytotoxic effects of NPs, NP exposure may also have subtle impacts on secondary processes such as metal nutrition. © 2014, Springer Science+Business Media New York