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Assessment of genetic diversity in Aspergillus carbonarius through random amplified polymorphic DNA (RAPD) marker analysis

1Thomas, B. T., *1Coker, M. O., 1Popoola, O. D., 1Adesetan, T. O., 1Banjo, O. A., 1Taiwo, O. S., 1Popoola, K. E., 2Thomas, A. N., 1Adegbe, G. M., and 3Owolabi, S. L.

1Department of Microbiology, Olabisi Onabanjo University, Ago-Iwoye, Ogun State, Nigeria

2Department of Animal Production, Olabisi Onabanjo University, Ago-Iwoye, Ogun State, Nigeria

3Department of Science Laboratory Technology (Microbiology Unit), Gateway Polytechnic, Saapade, Ogun State, Nigeria

*Correspondence to: olawunmi.coker@oouagoiwoye.edu.ng; +2349054006625; ORCID ID: https://orcid.org/0000–0003–0937-7755

 

Abstract:

Background: The importance of RAPD in revealing genetic diversity among ochratoxigenic strains of Aspergillus carbonarius lies in its ability to provide critical information that can support the development of effective strategies to limit ochratoxin A contamination in agricultural produce. This study therefore focused on evaluating the genetic diversity of 20 A. carbonarius strains previously isolated in an earlier investigation.    Continue reading “Assessment of genetic diversity in Aspergillus carbonarius through random amplified polymorphic DNA (RAPD) marker analysis”

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Assessment of genetic diversity among environmental Cryptococcus species using RAPD analysis

*Coker, M. O., Thomas, B. T., Efuntoye, M. O., and Popoola, O. D.

Department of Microbiology, Olabisi Onabanjo University, Ago-Iwoye, Ogun State, Nigeria.

*Correspondence to: olawunmimercy707@gmail.com; Mobile: +2349054006625;

ORCID ID: https://orcid.org/0000–0003–0937–7755

 

Abstract:

 Background: Cryptococcus species, including C. neoformans and C. gattii, are environmental yeasts of clinical importance and major agents of cryptococcosis. Environmental reservoir represents the primary source of human and animal infections therefore, characterization of genetic diversity is essential for epidemiological surveillance and understanding the pool of genotypes from which pathogenic strains may arise. Continue reading “Assessment of genetic diversity among environmental Cryptococcus species using RAPD analysis”

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Genetic diversity of ochratoxigenic Aspergillus section Nigri, using RAPD and VCG techniques

B.T. Thomas, L.A. Ogunkanmi, B.A. Iwalokun, D. Popoola

 

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.

Keywords; Genetic Diversity, Ochratoxigenic Aspergillus, RAPD and VCG

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Genetic diversity of ochratoxigenic Aspergillus section Nigri, using RAPD and VCG techniques