B. McBenedict, D. Haiyambo, P. Chimwamurombe*,
I. Mapaure and P. B. Nuuyoma

Department of Biological Sciences; University of Namibia, 340 Mandume Ndemufayo Avenue, Windhoek, Namibia.

Abstract

Vachelliatortilis is a tree belonging to the family Fabaceaethat inhabits high temperature and dryenvironments of the world. It isecologically and economically significant amongst others of the generaVachelliaand Senegalia. It is native to Namibia and several other countries. Various parts of the V. tortilis plant are used for different therapeutic purposes both in the traditional and pharmacological settings. However, V. tortilis is vulnerable to pathogenic infectionto which they lack natural resistance and little is known regarding the pathogens responsible for such infections. The aim of the study was to isolate and identify the fungal species associated with twig dieback disease in V. tortilis. Pure cultures from diseased V. tortilis were grown using potato dextrose agar (PDA) and DNA was subsequently isolated and later amplified in a PCR reaction using ITS1 and ITS4 primers. Sequencing and BLAST search revealed the identity of the isolates as; Penicilliumrubefaciens, Penicilliumherbarum, Trichodermalongibrachiatumand Trichodermaharzianum.Results indicated thatP. herbarumwas associated with disease symptoms in A. tortilis, T. longibrachiatum and T. harzianumwere antagonistic fungi while the effect of P. rubefaciens on V. tortilisremained unknown.It is recommended that further investigations using Koch’s postulatesshould be performed on V. tortilis using the isolates.

Keywords: Penicilliumrubefaciens, Penicilliumherbarum, Trichoderma -longibrachiatum,Trichodermaharzianum, Namibia, Vachelliatortilis