Abundance and Potency of Endophytic Fungi to Suppress Yellow Leaf Curl Disease in Chilli Pepper (Capsicum annuum L.).

Abstract

Incidence of yellow leaf curl diseases caused by Pepper yellow leaf curl begomovirus (PepYLCV) has become a major problem in chilli pepper growing area, especially in Java and Sumatra since early 2000. Disease incidence in the field may reach 20 % to 100% and the disease was obviously recognized by its unique symptoms involving bright yellow mosaic, mottle, curling, and stunting. A research was conducted to explore the potency of endophytic fungi as an alternative strategy to suppress PepYLC disease. Research activities consisted of 3 parts, i.e. (1) Isolation of endophytic fungi collected from chilli pepper plants at endemic area in Sleman, Yogyakarta; (2) Pathogenicity assay using chilli pepper seeds, and (3) Efficacy of selected endophytic fungi to suppress disease incidence. The result showed that diversity of endophytic fungi isolated from unsymptomatic plants were significantly higher than those from infected plants. There were 19 isolates of species identified from unsymptomatic plants; whereas 13 isolates from infected plants. Based on pathogenicity assay using 17 selected isolates, the endophytic fungi could be differentiated into 2 groups, i.e. pathogenic (13 isolates) and non-pathogenic (4 isolates). Further screening of non-pathogenic isolates showed that 4 isolates might have a potential as plant growth promoting fungi (PGPF) and 2 isolates, identified as Cercospora nicotianae and Pleosporaceae, might be recommended as bio-control agent. Endophytic fungi isolated in this study having potency as biocontrol agent was taken from low abundance population C. nicotianae was singleton and has potency as biocontrol agent for PepYLC disease.