TITLE:
In Vitro Antifungal Efficacies of Maize Associated Microorganisms
AUTHORS:
Esther Aanuoluwa Ekundayo, Bolatito Esther Boboye, Fatusa Clement Adetuyi
KEYWORDS:
Microorganisms, Antagonistic Activities, Chemical Fungicides
JOURNAL NAME:
Advances in Microbiology,
Vol.5 No.4,
April
24,
2015
ABSTRACT: Microorganisms
(bacteria and fungi) were isolated from different parts of yellow maize (stem,
cob, husk, leaf, root) as well as from rhizosphere and non-rhizosphere soil of
maize using conventional microbiological techniques. A total number of twenty-six
bacteria and thirteen fungi were isolated. The antagonistic efficacies of these
isolates were tested against Sclerotium
rolfsii, Aspergillus repens, Penicillium notatum and Pythium sp. using streak bioassay, food
poisoning and dual culture techniques. None of the bacteria was antagonistic to
the test fungi at 25°C on PDA using streak bioassay. However, there was
reduction in the population density of the test fungi using food poisoning
technique. The fungal isolates were antagonistic to the test fungi in varying
degrees. Generally, S. rolfsii was susceptible to seven out of
the eight fungal antagonists while P. notatum was least susceptible. The
percentage reduction of S. rolfsii ranged from 40.00 ± 5.78 to
64.07 ± 2.31. Efficacies of chemical fungicides; mancozeb, camazeb and red
force at 3 different concentrations— 0.05%, 0.1% and 1.0% (w/v) on the test
fungi were also determined. No growth of the test fungi was observed at 1%
(w/v) of all the fungicides while at lower concentration (0.05%), red force did
not have any inhibitory effect. The growth of S. rolfsii was completely
inhibited at 0.05% of mancozeb whereas there was reduction in mycelial growth
of A. repens. Effect of inoculation time and nutrients (PDA and MEA) was
determined on the antagonistic activities of Trichoderma viride. There were significant differences in
inhibitory potentials of the two isolates of Trichoderma viride when pre-inoculated on the culture medium. The
antagonistic potentials were more pronounced on malt extract agar than potato
dextrose agar.