Molecular Identification of a Fungus Associated with Galls Formation on Ficus cordata in the Otavi Mountains of Namibia

S. K. Ilonga and P. M. Chimwamurombe*

Department of Biological Sciences, Faculty of Science, University of Namibia, Private Bag 13301, 340 Mandume Ndemufayo Avenue, Windhoek Namibia.

Corresponding Author E-mail: pchimwa@unam.na

ABSTRACT: Ficus cordata is an angiosperm tree which belongs to the family Moraceae and genus Ficus. Ficus cordata has a wide distribution in Namibia. Fig trees are very useful plants ecologically, agriculturally or economically. Figs play an important role in maintaining the ecological balance. They produce fruits which are edible to both human and animals, and they provide shelter to grazing animals. F. cordata can be planted as a living fence and its leaves are used as mulch. In addition, its bark is used for tanning skins and for dyeing hides and making. The objective of the study was to isolate and identify the fungal species associated with gall formation on the Ficus cordata in the Otavi mountains of Namibia. Fungal species were isolated from the galls on the infected twigs and grown into pure cultures using Sabouraud Dextrose Agar (SDA) and later on Malt Extract Broth (MEB). DNA was extracted from dried mycelia and conserved internal transcribed spacer regions of the fungal species were amplified using the ITS1 and ITS4 primers. DNA amplicons were sequenced and compared to sequences of known organisms in the GenBank using nucleotide BLAST (Basic Local Alignment Search Tool). The BLAST search program revealed the identity of fungal species isolated consistently cultured as an isolate of Dothideomycete species (100 % similarity). However, further work of testing Koch’s postulates is needed to verify whether the Dothideomycete species is directly causing the formation of galls on the Ficus cordata.

KEYWORDS: Ficus cordata; Gall formation; ITS; PCR; Fungal pathogens

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