L. EBOIGBE

Aspergillus flavus is a fungus known for posing significant health risks in humans and animals. This study investigates the epistatic effect of double mutations induced by sodium azide and potassium chlorate in A. flavus. The mutants were generated were generated in culture media containing the mutagens and their epistatic interactions were observed along with their nutrient
utilization and growth rates. The results of mutation resulted in significant changes in the growth rate and morphology of the mutants, compared to the wild type. The epistatic interactions between the mutations revealed both synergistic and antagonistic effects on various traits. These findings provide insights into the genetic mechanisms underlying aflatoxin production and
fungal development in A. flavus, with implications for developing novel strategies to control aflatoxin contamination.

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.

Nine tomato genotypes collected from Nigerian Institute of Horticulture and National Centre for Genetic Resources and Biotechnology, Ibadan, were cultivated and screened for resistance to Oidium neolycopersici. The pathogen was cultured in the laboratory in potato dextrose agar as culture medium and re-inoculated to the leaves and root area of the screenhouse tomatoes. During the course of the experiment, there were expectations to find a resistant variety which will serve as a potential tool for cultivating resistant varieties of tomato. However, all accessions of tomatoes inoculated with the pathogen were evaluated and found to be susceptible to the pathogen. The pathogen totally colonised the plants, caused necrosis of the leaves,
prevented flowering and fruiting, and ultimately caused the death of all tomato plants observed in this study. The study showed that powdery mildew (Oidium neolycopersici) poses significant threat to greenhouse tomatoes, as well as tomatoes grown in the field.

In this study, screening and selection of Cryptococcus neoformans was conducted using Urease test. Pigeon dropping is known to be a source of this infectious organism. A total of twelve (12) samples from pigeon droppings were collected from three markets in Benin City. All samples were cultured on SDB (Sabouraud Dextrose Broth) and incubated for 24hrs at 37°C. After 24hrs, the isolates were sub-cultured on fresh SDB and incubated for 24hrs. After growth was observed, the isolates were plated on SDA (Sabouraud Dextrose Agar) for identification of the organism. Isolates of the organism obtained from this samples that was sub- cultured were subjected to urease test. Clinical samples collected from UBTH were also subjected to urease test. The results showed that the isolates that were positive for urease tests with highest growth rate at 37°C were recorded for samples x obtained from Oliha market. This experiment shows the possibility of isolating and selecting C. neoformans on urease test