Eksplorasi dan Uji Potensi Agensia Hayati Dark Septate Endophyte terhadap Busuk Pangkal Batang (Ganoderma boninense Pat.) Kelapa Sawit (Elaeis guineensis Jacq.)

Abstract

Basal stem rot caused by Ganoderma boninense is the most destructive disease in oil palm plantations in Indonesia. Biological control with microbes as biological control agents has been carried out. One of them is using Dark Septate Endophyte (DSE), a group of endophytic fungi that have potential as plant growth promoting in abiotic and biotic stress conditions. The aims of this experiment to obtain local DSE fungi isolates of North Sumatra from Ganoderma endemic areas which have the potential as biological control agents to control G. boninense. DSE exploration was carried out in the area of moderate Ganoderma incidence (5-30%) in Galang District, Deli Serdang Regency. The experiment was conducted at the Plant Laboratory in Patumbak District, Deli Serdang Regency and the Plant Disease Laboratory, Faculty of Agriculture, Universitas Sumatera Utara. The initial selection of in vitro pathogenicity tests obtained 5 non pathogenic DSE isolates with a germination percentage of 43%-60% isolates II 3A CM, Gelap A, II 4 CM, II 3A CC, and Abu-abu. The antagonist test results of the DSE isolate against G. boninense obtained a percentage of inhibition isolate I 3 A PK by 17.8% and 59.4% isolate Gelap A at observation 3 days after inoculation (DAI). Observation of 5 DAI, the lowest inhibition of isolate I 3 A PH (22.3%) and the highest inhibition is Gelap A isolate (74.1%). The inhibition of 7 DAI Gelap A isolate has reached out 100%. Macroscopic observations were made of upper and lower surface colony color, colony shape, elevation and colony edge with varying results. Microscopic DSE isolates are short septate hyphae, melanin branched hyphae, chain chlamydospores of isolates II 3 A CM. Short septate hyphae and melanin chlamydospores, septate hyphae and chlamydospores hyaline with chains form of isolate Gelap A. Multinucleate septate hyphae, uninucleate septate hyphae with fusiform macroconidia 1-3 septate of isolate II 4 CM. Branched hyphae and septate hyphae, melanin hyphae with intercalar chlamydospore of isolate II 3 A CC. Short septate hyphae with terminal chlamydosora, hyaline hyphae with melanin chlamydospore, and hyaline chlamydospores of isolate Abu-abu.