DEPARTMENT OF PLANT BIOLOGY AND BIOTECHNOLOGY

Soil salinity is one of the major environmental problems limiting seed germination and crop productivity in tropical agriculture. Corchorus olitorius L. (jute) is an important fibre and vegetable crop in Nigeria, yet its early growth is highly sensitive to saline conditions. This study evaluated the physiological response of two jute landraces. Landrace C (from NIHORT) and Landrace D (from Delta State) were treated to different salt concentrations to determine their level of tolerance. The experiment was conducted using a Completely Randomized Design (CRD) with five sodium chloride (NaCl) levels: 5 ppm (control), 200, 2000, 5000, and 10,000 ppm, each replicated three times. Growth parameters observed included germination percentage, shoot height, number of leaves, stem girth, number of branches, internode length, and leaf area. Data collected were analyzed using Analysis of Variance (ANOVA) at a 5% significance level. Results showed that salt stress caused a steady decline in all growth parameters. Landrace C had the highest germination rate (90.00 ± 17.32%) and best seedling growth at 200–2000 ppm, recording maximum shoot height (26.83 ± 4.64 cm) and leaf number (34.67 ± 1.70). Landrace D performed poorly, with peak germination at 200 ppm (20.00 ± 0.00%) and no growth beyond 2000 ppm. Analysis of variance (ANOVA) indicated significant differences (p < 0.05) among treatments and between landraces. Overall, Landrace C exhibited stronger salt tolerance due to better osmotic adjustment and growth stability, making it suitable for cultivation and improvement in saline prone soil.

This study examined the effects of illumination on the vitamin D and secondary metabolite contents of Pleurotus ostreatus (oyster mushroom) under different exposure durations. Fresh samples of the mushroom were subjected to varying illumination periods using both sunlight and ultraviolet (UV) light for 1, 2, 4, 6, and 8 hours. Ethanol extracts of the samples were subsequently analyzed for vitamin D and secondary metabolite contents. The results revealed that exposure to sunlight for six hours yielded the highest vitamin D content, indicating this as the optimum illumination period for vitamin D synthesis in P. ostreatus. Conversely, exposure to ultraviolet light showed inconsistent effects, with prolonged exposure leading to denaturation and a decline in vitamin D concentration. The impact of illumination on secondary metabolite constituents varied according to the observed secondary metabolite, light-sensitive compounds such as flavonoids and phenols decreased with extended exposure with flavonoids showing an optimum value display at 6 hours (0.39 mg/g) but decreased slightly to 0.36 mg/g after 8 hours, while saponins and terpenoids increased, possibly due to the softening of tissue cells that enhanced their production. Cardiac glycosides, being more resistant to light, remained relatively stable across treatments, maintaining (0.35 mg/g), with no statistically significant difference (p > 0.05). These findings highlight the significance of the effects of exposure of mushroom samples to sunlight and ultraviolet light at different time periods. The study also provides a basis for further research on optimal illumination at different time points to enhance and maximize vitamin D and phytochemical components of Pleurotus ostreatus.

Biopesticides, often known as biological pesticides, are compounds made from biological agents that control agricultural pests to increase crop yields. The general aim of using the term biopesticide is to suggest a biological rather than a synthetic origin of the active agent, and implicit is a level of environmental and mammalian safety resulting from the use of naturally derived active. Telfairia occidentalis is an edible vegetable that is high in protein, vitamins, iron, calcium, and other nutrients that are necessary for a healthy diet. The purpose of this study was to examine the effects of biopesticides on Telfairia occidentalis. This study was grouped into seven (7) biopesticides options compared to the control which no biopesticide was applied to. The biopesticides includes (Grinded pepper, garlic, and soap), (Grinded pepper and garlic), (Pepper, garlic and soap), (Pepper and garlic), (Neem oil and soap), (Neam oil) and lastly (Firewood ash). This study was carried out within 13 weeks, and the study was on different aspects of the plant growth which includes the plant height, the number of primary branches, leaf area, petiole length, tendril length, number of leaves, internodes, leaf chlorosis occurrence, and percentage of forage leaves. Across all aspects of the growth the Telfairia occidentalis treated with the biopesticides had significant increase compared to the control, which simply indicates positive effects across all. This study indicates that the biopesticides used are good pest control agents as a result of the growth and the good health of the plant. Asides from the fact that most of these biopesticides are good pest controlling agents, some are also a good agent for soil PH correction such firewood ash, and this also contributed to the growth and healthy profile of Telfairia occidentalis in the study.

This study examined the effects of vinegar on the growth of two freshwater microalgae: Scenedesmus sp. and Chlamydomonas sp.. The experiment was setup in triplicates of different concentrations of vinegar ( 0% (control), 1%, 5%,10%,15%,20% and 25%) in a culture media and monitored for 14 days. The samples were analyzed every two days to monitor growth using a visible spectrophotometer at a wavelength of 750nm as well as other physicochemical parameters such as pH, conductivity, turbidity, total dissolved solids and dissolved oxygen. The results were analyzed using statistical two way analysis of variance ANOVA repeated measures, paired t-test, microsoft excel and descriptive statistics. The result showed that the growth of Scenedesmus sp. and Chlamydomonas sp. were affected by the different concentrations of vinegar with a significant difference (p<0.05) across all parameters. The control (0% vinegar) recorded the highest growth, yield and dissolved oxygen while the 10%vinegar concentration produced the lowest values, indicating that increasing acidity inhibited algal growth and photosynthetic activity. The comparative percentage yield between both species showed no significant difference (p>0.05), suggesting comparable productivity under mild acidity

This study investigated the effect of scarification pre-treatments on the germination of Omphalocarpum elatum, Khaya anthotheca, and Albizia coriacea seeds. These tropical species are ecologically and economically significant but face regeneration challenges due to seed dormancy and hard seed coats that prevent water absorption and gas exchange. The research aimed to evaluate whether scarification pre-treatments could enhance their germination and overcome dormancy. The experiment was conducted at the Screen-House of the Department of Plant Biology and Biotechnology, University of Benin. Four seeds were planted per pot, and each species had fifteen pots, making a total of forty-five pots for the entire study. The parameters recorded were the number of seeds planted and the percentage of germination, and observations were made daily for thirty days. The results showed that no germination occurred in any of the species throughout the observation period, as the number of germinated seeds for all species was zero, resulting in a 0% germination rate. This complete lack of germination may have been caused by several factors such as delay in seed planting after procurement, harsh scarification procedures like acid treatment, the potency or viability of the seeds (dead or alive), unfavorable environmental conditions, and the nature of seed collection whether from trees or fallen fruits. The study concludes that proper seed handling, immediate planting after harvest, the use of mild scarification methods, and seed viability testing are essential for improving germination outcomes. Although no germination was recorded, the findings provide valuable baseline information for future research aimed at enhancing propagation techniques and promoting the conservation and restoration of tropical forest sp

The study eutrophication stimulation effect on river Eruvbi phytoplankton was done to observe the growth response of the phytoplankton to different nutrient enrichment. Water samples were collected from the river site as well as phytoplankton samples. The phytoplankton was subjected to microscopic examination. The study involved natural phytoplankton population and introduced algae of (Scenedesums acutus and Chlorella vulgaris). The nutrient concentration used were 2.4mg/L nitrate, 1.2 mg/L phosphate and 2.4 mg/L nitrate + 1.2 mg/L phosphate, growth measurement was done optically using spectrometry at 750nm. The physiochemical composition of the river was also carried out, with some done in situ and others done in the laboratory. The result of the stimulated experiment showed that indigenous phytoplankton growth was best stimulated by nitrate enrichment, while introduced phytoplankton responded better to phosphate enrichment. The phytoplankton composition of river Eruvbi has a low biodiversity and the algae present show the river to be oligotrophic in nature. Some physiochemical parameters such as dissolved solid, total alkalinity, total hardness and turbidity fell within the WHO guidelines for drinking water, while others like dissolved oxygen and pH were above the WHO guidelines for drinking water. It was concluded from the results that river Eruvbi which is oligotrophic as at present will under eutrophication if subjected to nitrate enrichment which will also cause a rapid bloom in the phytoplankton species of the river. Therefore extra care must be taken to prevent the eutrophication of the river.

Justicia carnea, also known as the Brazilian Plume Flower, is a tropical shrub from the Acanthaceae family, admired for its striking pinkish-red flowers and lush green foliage. Often grown as an ornamental plant, it attracts pollinators like bees and butterflies while adding vibrant color to gardens. Beyond its beauty, Justicia carnea has long been used in traditional medicine for treating anemia, respiratory issues, and inflammation due to its antioxidant and immune- boosting properties. The plant thrives in warm climates with well-drained soil and partial shade, making it a resilient yet eye-catching addition to landscapes. On a cellular level, it exhibits stable meiosis and amphistomatic leaves with diacytic stomata, which help regulate gas exchange and water loss. With its combination of aesthetic appeal, ecological importance, and medicinal value, Justicia carnea remains a valuableplant for both gardeners and researchers alike.

Soybean (Glycine max [L.] Merr.) Is one of the most essential oil plant that is largely grown globally. Its domestic and industrial use hasbrought about increase in the economy of many countries. About 64 % of the world's supply of oil seed meal comes from soy, which also serves as the primary source of oil and contributes to about 28 % of output as a whole. Soybean which is a legume crop serves as food to humans and animals and other beneficial purpose. 10 different accessions of soybean were studied to check if there will be significant change in their morphological and physiological characteristics. The set of descriptors for the present morphological characterization of Soybean was produced using the Sphenostylis stenocarpa (Hochst ex. A. Rich.) Harms descriptor and the seed length, seed width and seed thickness of 10 seeds from each accession number were determined using a venire caliper. Accession number TGM-942 had the least length, 0.47 cm while Accession number TGM-944 had the highest length, 0.58 cm. Accession number TGM-540 seed weighed 1.45 g, which was the highest see weight. Their testa basal colorranged from black, reddish brown, light brown, black to purple.

Soil contamination by heavy metals especially chromium (vi) oxide is a major environmental concern due to its toxicity and persistence inagricultural soils. This study investigated the effect of chromium (VI) oxide on the growth and anatomy of Sorghum bicolor to assess its tolerance and sensitivity. Sorghum seeds were subjected to five concentrations of chromium (VI) oxide (0, 30, 50, 70, and 100 ppm) in soil, under a completely randomized design (CRD) with four replicates per treatment. Growth parameters, including germination percentage, plant height, stem girth and number of leaves, were studied and recorded up to six weeks after planting (WAP). Anatomical analyses of root and stem transverse sections were performed to assess internal tissue responses. Results showed a concentration specific decline in all growth parameters, with the control plants exhibiting the highest mean values for germination percentage (20.00%), plant height (59.50cm) and stem girth (0.84cm) and the least values for germination percentage (10.75%), plant height (36.00cm) and stem girth (0.76) recorded for plants grown in 100 ppm Cr6+ treatment. Vegetative growth parameters decreased with increasing chromium concentration, indicating growth suppression. Anatomical observations revealed darkening of the epiblema and loss of cortical cells in the root of plants as well as deposition of crystal-like substance is observed in the cortex of the stem of plants exposed to higher chromium levels. These alterations indicate that chromium induces oxidative stress and structural injury, disrupting normal cell function and secondary growth. The findings support that chromium (VI) exerts significant inhibitory effects on both morphological and anatomical development of Pennisetum glaucum, emphasizing the detrimental impact of chromium contamination on crop productivity.

One of the world’s most important vegetable plants is the tomato (Solanum lycopersicum). It can be consumed raw, cooked, or utilized to make items with tomato as the base. Because lycopene is one of the main sources of carotenoids, it has also been proven to be helpful in studies involving these pigments. In order to identify the tomato genotype that is most likely to be used in tomato breeding, this research was done to characterize three inbreed lines of tomato genotypes from Igbodo. The identification of genetic variability that exists within crop germplasms depends on agronomic evaluation of crop genotypes. In order to do this, the fruits of 3 tomato genotypes were assessed, using a UV spectrophotometer, the lycopene content was calculated. Fruit weight ranged from 6.222±0.660 to 13.96±1.661. RD-igb had the highest fruit weight while PY-igb had the lowest fruit weight. The lycopene content was evaluated for three genotypes; RD-igb, HD-igb and PY-igb. Genotype 2 recorded the highest fruit lycopene content with a value of 1.336±0.321 to 1.715±0.253 while genotype 1 recorded the lowest fruit lycopene content. Some attributes had a significant coefficient of variance, whilst others showed little genotype-to-genotype variation. While some genotypes, such as genotype 1, had low fruit lycopene values, genotype 2 had high fruit lycopene content. When choosing tomato plants with desirable qualities during tomato breeding, these tomato unique diversities can be used as a guide.