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

Abstract

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.


African Jnl Biotechnology Vol.3(3) 2004: 195-198