DEPARTMENT OF PLANT BIOLOGY AND BIOTECHNOLOGY,

The purpose of this study was to determine the effect of selected tuber-based media on the vegetative growth of the fungus Volvariella volvacea (Bull. Ex Fr.) Sing. Pure culture of V. volvacea was gotten from the African Centre for Mushroom Research and Technology Innovations, University of Benin, Benin City, Nigeria. The pure culture was expanded aseptically on potato dextrose agar and stored until utilized. This evaluation was carried out by puncturing the pure culture with already sterilized cork borer then the inoculum was collected with an already sterilized loop and inoculated at the center of the formulated culture. The culture media were subjected to different orientations. This procedure was carried out for the five replicates of each formulated medium after which they were taken to the incubation room. The growth biometry was taken after 24 hours for 6 days. Potato dextrose agar recorded the highest mycelia growth on the different plate orientations while cocoyam dextrose agar and white yam dextrose agar recorded the lowest mycelia growth on plates with an upward orientation and plates with a downward
orientation respectively. From this study it has been observed that the vegetative growth of Volvariella volvacea is influenced by the plate orientation and the tuber used to prepare the culture media.

Antibiotics play a crucial role in medicine, aquaculture, and agriculture, but their persistence in wastewater and runoff poses significant environmental risks, particularly for aquatic ecosystems. This study evaluated the effects of tetracycline and chloraphenicol on the growth of Acutodesmus acutiformis, a freshwater green microalga.. The experiment involved culturing A. acutiformis with varying concentrations (0, 5%, 10%, 20%,30%,40%,50%) of tetracycline and chloramphenicol under controlled laboratory conditions at the University of Benin. Microalgal growth was monitored spectrophotometrically at 750 nm over 14 days, alongside physicochemical parameters such as temperature, total dissolved solids (TDS), pH, conductivity, turbidity, dissolved oxygen (DO), chemical oxygen demand (COD), and total organic carbon (TOC). Statistical analysis (one-way ANOVA, paired t-test descriptive statistics) revealed significant differences (p < 0.05) in growth response and water quality parameters except for tetracycline and for chloramphenicol which had no significant difference with regards the antibiotic concentrations with a percentage yield of (P<.05). Tetracycline exhibited a dose- dependent effect, promoting growth at 50% concentration but inhibiting it at higher levels, while chloramphenicol significantly promoted growth possibly due to the presence of proteisynthesis. The growth response of Acutodesmus acutiformis was revealed using an interval of 0 -14days. Meanwhile the result of the physicochemical parameters such as temperature, pH, TD and conductivity after been acted by antibiotic concentration of tetracycline and chloramphenicol were revealed in various upward and downward trend, it was observed that both antibiotics influenced algal growth.

Studies on the morphology and cytology of two species, Aspilia africana and Spilanthes costata B. family Asteraceae, were conducted. The departmental botanical garden served as the source for the many specimens used.
The following was done cytological study, which includes mitosis and meiosis; tests showed that it was not possible to successfully confirm the chromosomal numbers of the two specimens. Epidermal morphology results showed that both specimens had anomocytic stomata and were amphistomatic. The average specimen height, as well as the average length and breadth of the leads, were determined and reported. Fertility in pollen was noticed