Annual Research & Review in Biology

Cassava anthracnose is a plant disease that affects cassava stems, petioles and fruits. The aim of this study was to analyze the diversity of cassava anthracnose symptoms in Ivory Coast and then to identify and characterize the associated fungal genera. Surveys were carried out in all agricultural zones of the country from July to November, in 2014, 2015, 2016 and 2017. Infected samples consisting of stems cut with a small number of superficial cankers (0.3%), distorted stems (25.77%), and necrotic stems and petioles (65.18%) were collected. Also, withered and dried apical buds (8.76%) were harvested. Fungal pathogens derived from samples were Colletotrichum gloeosporioides (35.08%), Fusarium sp. (27.19%) and Botrytis sp. (19.73%) genera and undetermined strains (17.98%). Genera were characterized by morphological and microscopic characteristics. Parasitic pressure increased to 80 and 100% respectively for Botrytis sp. genus and Colletotrichum gloeosporioides and Fusarium sp genera. Fungal genera have caused lesions on stem and petioles in green house with diameters sizes 46, 71 and 72 mm respectively for genera Botrytis sp, Fusarium sp and Colletotrichum gloeosporioides. Aggressiveness index of Botrytis sp. genus was 3 and 4 respectively for Colletotrichum gloeosporioides and Fusarium sp. genera. The mycoflora of cassava aerial organs alteration, linked to the symptoms of anthracnose, is composed of genera of great economic importance and scientific interest.

Fruits are one of the most important agricultural products that supply the body with vitamins and essential minerals elements, but it is contaminated by fungi during the period of growth, harvesting and storage. A. niger is one of the species that grows on the fruit during the period of storage, and secretes mycotoxins especially ochratoxin A. This study was conducted with the purpose of isolating  and identifying different strains of A. niger from 20 samples of pear collected from Taif markets and to determine the ability of these strains to produce OTA. It was observed that showed that out of 20 pear samples collected, 19 samples were detected to be contaminated with different strains of A. niger and the strains were able to produce OTA. From 27 isolates of A. niger which was  used to test the ability of production OTA, 10 strains only produced OTA. The range of OTA in all strains were 0.18 to 9.5 ppb. Representative 27 strains of ochratoxigenic and non ochratoxigenic black Aspergilli isolated were subjected for detection of ochratoxin biosynthesis genes, by using  two sets of primer for two genes involved in ochratoxin biosynthetic pathway. Bands of the fragments of PKS15C-MeT and PKS15KS genes visualized at 998 and 776 bp, respectively. Whereas, the presence of four tested genes is not sufficient marker for differentatin between aflatoxigenic and non aflatoxigenic isolates.

Aim: This study deals with the distribution and ecology of euglenoids in relation to physicochemical characteristics of water in four lakes of Tumakuru district.

Place and Duration of Study: Guluru, Bugudanahalli, Colony and Teeta are the four lakes of Tumakuru district selected for the present study during 2015-17.

Methodology: Euglenoids function as indicators of aquatic superiority. Composite samples were taken at two feats depth from surface level on monthly basis for the enumeration of euglenoids. Results: A total of ten species under three genera were identified. Guluru lake harboured 46.66% followed by Colony and Teeta lakes 20% each and Bugudanahalli lake with 13.33%. Seasonally all the lakes recorded maximum density of euglenoids during summer except in Colony lake, where they reached their peak during rainy season. Euglenoids showed significant positive correlation with water temperature (r = 0.664: P < 0.05), Sulphate (r = 0.757: P < 0.05) and Silica (r = 0.775: P < 0.05) at 5% level.

Conclusion: Euglenoids established negative correlation with dissolved oxygen and ammoniacal nitrogen. As the euglenoids serve as pollution indicator organisms, moderate density of euglenoids in the lakes investigated indicates that, lakes are tending towards biologically eutrophic condition.

Phenolic compounds are dominant pollutants in terrestrial and freshwater environmental that have toxic effects on living organisms at low concentrations, because it has the ability to persist in the ecosystem. So bio-removal is a good technique that employs the metabolic potential of microorganisms to clean up the environmental pollutants and turned into less dangerous or harmless substances. This work aims to the isolation of different species of fungi from wastewater of factories and Red Sea coast to test the ability of these fungi to degrade phenolic compounds. Ten species of fungi and sterile mycelium are used to degrade phenol and its derivatives at different concentrations (0.4%, 0.6% and 0.8%). All fungi species have the ability of degradation of phenol and their derivatives, but P. chrysogenum, Saccharomyces sp. and sterile mycelium exhibited low ability to break down of hydroxyl-benzene, 2-naphthol and 1,3 dihydroxy benzene, respectively.

The aim of the study was to find the antioxidant activity and enzyme activity of catalase and peroxidase of vegetable plants. The results indicated that the use of seaweed liquid fertilizer can enhance the antioxidant activity of Solanum melongena L., Lycopersicon esculentum Mill., Capsicum annuum L., Brassica oleracea var. Capitata L. and Allium cepa L. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used to determine the antioxidant properties of seaweeds by measuring the decrease in absorbance at 517 nm. The DPPH activity was highest in brown seaweed liquid fertilizer. This study implied that impacts on vegetable plantlets by seaweed liquid fertilizer extracted with enzymes is better in brown seaweed liquid fertilizer as compared to control.