EXPLORING FUSARIUM SPECIES AS POTENTIAL BIOLOGICAL CONTROL AGENT AGAINST STRIGA HERMONTHICA

Abstract

Striga species also known as witchweed are obligate root parasitic plants mostly found in sub Saharan Africa (SSA). S. hermonthica, S.gesnerioides and S.asiatica parasitize most essential cereal crops leading to low yield and productivity. Available management efforts have been less or not effective at all due to the cost involved and the life cycle of the parasite. The development of biocontrol agents has shown to be one of the most effective ways in controlling Striga. This study was aimed at isolating and identifying of Fusarium isolates from diseased Striga leaves that have biocontrol potential against striga spp. The CTAB method was used to obtain DNA from isolated fusaria. Relying on sequences of translation elongation factor 1 alpha, the fusarium species were confirmed to be Fusarium duofalcatisporum (7), Fusarium incarnatum (1), Fusarium oxysporum (4), Fusarium fredkugeri (1) and Fusarium verticillioides (1). An in-vitro detached leaf assay was used to estimate the pathogenicity of the various Fusarium isolates. Lesions caused by the five Fusarium species on Striga hermonthica varied from 1.00 to 3.75 mm and 1.44 to 4.44 mm for week 1 and week 2 respectively. An analysis of variance indicated significant interactions between Fusarium isolates and the Striga leaves. Isolate F. oxysporum-C9 had the lowest lesion effect while F. fredkugeri-C10 exhibited the highest lesion on the Striga hermonthica leaves.