Genetic Diversity of Ochratoxigenic Aspergillus Section Nigri, Using RAPD And VCG Techniques
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Date
2017-09
Authors
Thomas, B.T.
Ogunkanmi, L.A.
Iwalokun, B.A.
Popoola, O.D.
Journal Title
Journal ISSN
Volume Title
Publisher
AFRICAN JOURNAL OF CLINICAL AND EXPERIMENTAL MICROBIOLOGY
Abstract
This study evaluates the genetic diversity of ochratoxigenic Aspergillus section Nigri using RAPD and VCG
techniques. Results obtained revealed OPX 07 as the most informative of the tested RAPD markers generating 12
polymorphic bands while the least bands were generated by OPR 19. Of the 40 Aspergillus section Nigri (20 each of
Aspergillus niger and Aspergillus carbonarius), 22 VCGs and 27 RAPD haplotypes were delineated. The two
techniques demonstrated similar resolution except in few cases where the RAPD technique further sub divided some
VCGs into simpler haplotypes. The average percentage of variable VCG and RAPD reactions were 25 and 50% in
that order of sequence while 75 and 50% of the isolates were resolved as same isolates by these techniques
respectively. It was also found that the Simpson index of genetic diversity approached one for the isolates from the
four geopolitical zones of Ogun State, Nigeria with the mean genetic diversity within isolates (GL) contributing
significantly approximately 89% of the total diversity observed within the isolates (F=22.23, p<0.05). The remaining
11% of variation could only be allotted to diversity among isolates (GS). On the whole, the total genetic diversity (HT)
was found to be approximately 48%. In conclusion, RAPD markers provided better resolution than the classical VCG
typing technique.
Description
Keywords
Genetic Diversity, Ochratoxigenic Aspergillus, RAPD and VCG
Citation
Thomas, B.T., Ogunkanmi, L.A., Iwalokun, B.A., & Popoola, O.D. (2017a) Genetic Diversity of Ochratoxigenic Aspergillus Section Nigri, Using RAPD And VCG Techniques African Journal of Clinical And Experimental Microbiology 18 (4): 205-209