Beauveria bassiana is an entomopathogenic fungus that grows
naturally in the soil all around the world and occurs in a wide range of
habitats, in forest soil and soils of urban areas. It is one of the most common
entomopathogenic fungi that is parasitic to several arthropod species and can
cause infection at all stages of life for the host insect. Beauveria bassiana
exhibits variations in molecular composition across varying locations. This
study aims to detect variations in the Beauveria species collected from some
locations in Ondo, Osun and Oyo States of South West Nigeria. Ten isolates of
B. bassiana isolated from soil samples collected from forest and urban sites in
three States of Southwest Nigeria were characterised using morphological and
molecular tools. The morphological characteristics examined included radial
growth, colour of colonies, texture, shape of the spores and filaments and the
relationship of the spores to the filaments. Means were separated using
Duncan’s Multiple Range Test at a 0.05% level of significance. DNA was
extracted from the isolates, and results from the OTU clustering were sequenced
using ITS1 and ITS4 primers. Results showed slight variation in colour of the
colonies, varying from whitish cream to white, having smooth, powdery textures
with colonies becoming more identical as plates extended, with no significant
differences in texture and elevation of the colonies. The radial growth of the
isolates was fast, with complete plate cover of the 9 cm Petri dish plates
within 7 days for all the isolates. Microscopic observations (×10 and ×100)
revealed whorled conidiophores with dense clusters of short, globose
conidiogenous cells showing an apical zigzag pattern and producing one-celled
spherical conidia, contributing to colony uniformity. Isolate sequences showed
a 100% homology to B. bassiana having molecular character variations with
isolates 6, 4, 9, 3, 2 having percentage similarity of 99.86 with B. bassiana
with accession no BbN06B02, isolate 5 had a percentage similarity of 90.62 with
B. bassiana with accession number MW633220.198-48 and isolates 7 and 8 had a
percentage similarity of 99.18 with B. bassiana with accession number
AY805547.1:180-346 as represented in the dendrogramic tree. These observed
variations could be utilised in biological insect pest management. Further
pathogenicity testing is recommended to determine the effect of location
variation on the virulence of the B. bassiana.
Author(s) Details
Oluwadara, A. B.
The Federal University of Technology Akure, Ondo State, Nigeria.
Oni, M. O.
The Federal University of Technology Akure, Ondo State, Nigeria.
Adebayo, R. A.
The Federal University of Technology Akure, Ondo State, Nigeria.
Fayeun, L. S.
The Federal University of Technology Akure, Ondo State, Nigeria.
Ajayi, O. O
Soil Microbiology Unit, The International Institute of Tropical
Agriculture, Ibadan, Oyo State, Nigeria.
Please see the book here:- https://doi.org/10.9734/bpi/rpbs/v6/5789
