African Journal of Biotechnology Vol. 3 (3), pp. 195-198, March 2004

ISSN 1684–5315 © 2004 Academic Journals

Full Length Research Paper

Colletotrichum circinans and Colletotrichum coccodes can be distinguished by DGGE analysis of PCR-amplified 18S rDNA fragments

Olajire Fagbola¹⁺ and Mathew M. Abang²*

¹Federal Biological Research Centre for Agriculture (BBA), Messeweg 11/12, D-38104 Braunschweig, Germany.

²German Collection of Microorganisms and Cell Cultures (DSMZ), Messeweg 11/12, D-38104 Braunschweig, Germany.

*Corresponding author. Present address: IRAD, P. O. Box 2123 Messa-Yaoundé, Cameroon, and Germplasm Program, International Center for Agricultural Research in the Dry Areas (ICARDA), P.O. Box 5466, Aleppo, Syria. E-mail: m.abang@cgiar.org.

+Present address: Dept of Agronomy, University of Ibadan, Ibadan, Nigeria.

Accepted 29 December 2003

The rDNA 18S region of Colletotrichum circinans and C. coccodes was amplified by PCR to evaluate this DNA region as a tool for species delineation. PCR amplification of the 18S of both species produced 1.65 Kb long fragments that covered most of the entire 18S rDNA molecule. DGGE analysis of the amplified fragments distinguished C. circinans from C. coccodes isolates. This result provides molecular evidence that supports the current treatment of C. circinans as a species distinct from C. coccodes, in spite of the failure of previous attempts at genetic differentiation of the two species based on RFLP analysis of the rDNA ITS region.

Key words: DGGE, Colletotrichum circinans, Colletotrichum coccodes, molecular differentiation, species delineation.