Search

Abstract The development of antiretroviral therapy has brought a tremendous relief to the world as it minimizes mortality, reduces HIV transmission, and suppresses progression in infected patients. However, the orthodox antiretroviral therapy is faced with limitations which have necessitated a continuous search for more novel plant-based antiviral compounds, which can bypass the existing barriers created by drug resistance and target more viral proteins. Despite the edibility and enormous pharmacological benefits of T. portulacastrum, little is known about its nutrient profiles and potential use as a natural source of antiviral drug. This study focuses on the full feed analysis and anti-HIV potential of two biotypes of T. portulacastrum. Ethanolic extracts of both biotypes of T. portulacastrum (T01 and T02) had significant inhibitory effects on the level of replication of the HIV-1. Both extracts induced the inhibition of at least 50% of the HIV-1 viral load at considerably low IC50 values of 1.757 mg/mL (T01) and 1.205 mg/mL (T02) which is comparable to the AZT standard. The protein composition ranged between 8.63-22.69%; fat (1.84-4.33%); moisture (7.89-9.04%); fibre (23.84-49.98%); and carbohydrate content (38.54-70.14%). Mineral contents of tested T. portulacastrum varied considerably in different parts of the plant. Nitrogen N mineral ranged between 13.8-36.3 mg/g; sodium Na (2.0-14.0 mg/g); potassium K (14.0-82.0 mg/g); magnesium Mg (2.8-7.1 mg/g); calcium Ca (9.1-24.7 mg/g); phosphorus P (1.3-3.6 mg/g); iron Fe (193.5-984.0 ppm); zinc Zn (42.5-96.0 ppm); manganese Mn (28.5-167.5 ppm); and copper Cu (2.0-8.5 ppm). These mineral values are comparable or higher than values quoted for common vegetables, suggesting that T. portulacastrum is a nutrient-dense vegetable that could provide alternative sources of antiviral nutrients to HIV-infected individuals. Further studies are recommended to unravel key metabolites responsible for high nutrient profiles and antiretroviral effects in T. portulacastrum.

Pepper (Capsicum spp.) growth and yield are reduced because of its susceptibility to water shortage which may be improved by application of potassium salts. Effects of concentrations of K2SO4 and KNO3 on growth and some yield parameters of C. annuum L. and C. chinense L. under artificially initiated drought were studied. Growth parameters like fresh and dry weights, Leaf Area Ratio, Leaf Weight Ratio, Relative Growth Rate and Net Assimilation Rate were determined at harvest. Yield parameters like number of flowers, number of fruit, fruit length, fruit diameter, fruit fresh weight and fruit dry weight were determined. There was a significant interaction of salt types, water levels and pepper types on all the growth, yield and biomass parameters studied.

Contamination of urban-garden vegetables with potentially toxic elements (PTEs) is a great problem in developing countries. This study assessed the level of PTEs (Cu, Pb, Cr and Cd) in market-sold vegetables in southwest Nigeria and evaluated the estimated daily intake (EDI) to understand the health implications. Level of PTEs in 80% samples exceeded the FAO/WHO permissible limits. The EDI for Pb exceeded the permissible limit by 1.8% and 5.4% in adults and children, respectively. m hazard quotient (HQ) of Pb in adults exceeded USEPA limit by 3-fold. The HQchildren for Cu, Pb and Cr exceeded USEPA limit by 1.5-, 6.9- and 1.5-fold, respectively. Hazard index for adults and children exceeded the recommended value by 11- and 3-fold, respectively. Cancer risk of Pb, Cr and Cd in adults and children exceeded the USEPA limit. Conclusively, consumption of vegetables in this region of Nigeria portends potential human risk to adults and children.

This study aimed at investigating the critical growth stage of weed removal in cowpea in order to prevent unacceptable yield loss during water deficit. The study was carried out under a screenhouse to minimize extraneous factors such as pests and rodents using a complete randomized design (CRD) with five replicates. Seeds of cowpea and early germinating seedlings of Tridax procumbens and Chromolaena odorata were used for this study and were stressed for five days. Samplings were carried out at vegetative, flowering and fruiting stage. Growth indices such as relative growth rate, net assimilation rate, leaf area ratio and tissue water of contents of cowpea were determined from plant biomass. The photosynthetic pigments were determined spectrophotometrically at different stages of growth. Weed interference index such as relative crowding coefficient and land equivalents ratio were also determined from the plant biomass. The results indicated that the growth indices of cowpea interfered by Chromolaena odorata and Tridax procumbens were greatly reduced at flowering stage compared with the growth indices at vegetative and fruiting stage. Photosynthetic pigments such as chlororphyll a, chlorophyll b, carotenoids and total chlorophyll of cowpea as interfered by Chromolaena odorata and Tridax procumbens were also lowest at flowering stage. Interference index of cowpea were lowest at flowering stage as to the vegetative and fruiting stage of cowpea. There was significant difference in the growth indices, photosynthetic pigments accumulation and interference index of at the different growth stages of cowpea at p≤0.05. From the results obtained, flowering stage is the most critical period of growth stage to remove weed in cowpea under water stress in order to prevent an unacceptable yield loss.

The use of phosphorus (P) to alleviate soil nutrient deficiency alters resources in plant and microbial communities, but it remains unknown how mixed and monospecific planting of forest tree species shape soil microbial structure and functions in response to drought and its interplay with phosphorus addition. We investigated the microbial structure and chemical properties of forest soils planted with P. zhennan monoculture, A. cremastogyne monoculture, and their mixed cultures. The three planting systems were exposed to drought (30–35% water reduction) and the combination of drought with P. A well-watered treatment (80–85% water addition) of similar combinations was used as the control. Planting systems shaped the effects of drought on the soil microbial properties leading to an increase in nitrate nitrogen, urease activity, and microbial biomass carbon in the monocultures, but decrease in mixed cultures. In the monoculture of P. zhennan, addition of P to drought-treated soil increased enzyme activities, the concentration of dissolved organic nitrogen, and carbon, leading to increase in the total bacteria, G+ bacteria, and arbuscular mycorrhizal fungi. Except in the drought with P addition treatment, the impact of admixing on total phospholipid fatty acids (PLFAs), bacterial PLFA, and fungi PLFA was synergistic in all treatments. Our findings indicated that in monoculture of P. zhennan and its mixed planting with A. cremastogyne, greater biological activities could be established under drought conditions with the addition of P.

This study aimed at determining the responses of some of the growth parameters of Lycopersicum esculentum to light and nutrient stress. The focus is equally orientated in determining the effect of light and nutrient stress on the photosynthetic pigment accumulation in plants. Tomato seeds were grown in pretreated sand and were watered with distilled water until the experimental culture was fully established. After this, the plants were transplanted into 60 plastic pots, with holes bored at the bottom to allow proper drainage of the excess water during the course of the experiment. The plants were divided into four groups of fifteen pots each. A group of plants was submitted to stress of nutrient lack by only administering 100 ml of complete nutrient solution, once every four days. The nutrient solution if applied daily was considered to be adequate for the plants. Another group of plants was lightly stressed, by placing them under shade, while adequate light was gotten in direct sunlight. Sampling was carried out at weekly intervals, starting from the seventh day after the first treatment. Plants were randomly picked from each of the four treatments. Three replicates were used for each parameter. The results showed that there was a reduction in photosynthetic pigment accumulation in the plants when both light and nutrient were limited. The data obtained from the study were first tested between normality and assumption of constant variance. A two-way analysis of variance (ANOVA) was carried out considering both factors (light and nutrient ) as source's of variation to investigate the effects of full light and full nutrient (FLFN ), full light and partial nutrient (FLPN), partial light and full nutrient (PLFN) and partial light and partial nutrient (PLPN) the parameters studied in Lycopersicum esculentum.

The experiment was carried out to determine the effects of heat stress on some growth parameters like shoot height, leaf area, fresh weight, dry weight as well as the accumulation of chlorophylls in Carica papaya. Seedlings of C. papaya were exposed to prior heat stress at 40 °C. A group of plants was placed in a Gallenkamp oven for four hours; another group of plants was placed in the oven for eight hours while the third group of plants was placed in a dark cupboard for the period of eight hours. Sampling was carried out at weekly intervals starting from seven days after treatment. Plants were randomly picked from each of the three treatments. Three replicates were used for each parameter. The results obtained from the study showed that there was an increment in the shoot height, leaf area, fresh weight and dry weight from the beginning to the end of the experimental period. However, the accumulation of chlorophylls did not follow a particular pattern. The analysis of variance carried out on the data obtained showed that heat stress had a significant effect on the petiole length, shoot height, leaf length, leaf width, leaf area, fresh weight and dry weight. Heat stress, however, did not produce a significant effect on the accumulation of chlorophylls a and b and total chlorophyll.