The molecular grouping of Fusarium isolates on cassava in Nigeria

The Fusarium isolates molecularly grouped in this experiment were isolated from the roots of three cassava genotypes (TMS 30572, TMS 4(2)1425 and TME-1) harvested in Ibadan derived savanna, Sabongidda-Ora humid forest and the Onne humid forest regions of Nigeria in 2004 and 2005. Isolates were previously identified using conventional morphological characters at the Plant Pathology Laboratory of the International Institute of Tropical Agriculture, Ibadan. Molecular grouping was done using amplified fragment length polymorphism at the Fusarium Laboratory of the Kansas State University, Kansas, USA. The molecular groupings agreed with the conventional morphological identification. Ten distinct amplified fragment length polymorphism (AFLP) groups of Fusarium were distinguishable, each group probably a distinct species, and many of them might represent previously undescribed Fusarium species. The two largest of the AFLP groups correspond to F. oxysporum and F. solani species complex. F. solani is an important root rot pathogen of cassava Nigeria.