Impact of Fungal Endophyte Colonization of Maize ( L.) on Induced Resistance to Thrips- and Aphid-Transmitted Viruses.

In eastern Africa, Maize lethal necrosis (MLN) is caused by the co-infection of maize plants with (MCMV) (Tombusviridae: ) and (SCMV) (Potyviridae: ). With the disease being new to Africa, minimal effective management strategies exist against it. This study examined the potential of 10 fungal isolates to colonize maize plants and induce resistance against MCMV and SCMV. Maize seeds were soaked in fungal inoculum, sown and evaluated for endophytic colonization. Fungus-treated plants were challenge-inoculated with SCMV and/or MCMV to assess the effects of fungal isolates on the viruses in terms of incidence, severity and virus titers over time. Isolates of , and colonized different plant sections. All plants singly or dually-inoculated with SCMV and MCMV tested positive for the viruses by reverse transcription-polymerase chain reaction (RT-PCR). Maize plants inoculated by and resulted in up to 1.4 and 2.7-fold reduced SCMV severity and titer levels, respectively, over the controls but had no significant effect on MCMV. The results show that both and are potential candidates for inducing resistance against SCMV and can be used for the integrated management of MLN.