Uji Antagonis Trichoderma spp. terhadap Fusarium sp. dan Identifikasi Molekuler Trichoderma spp. asal Kalimantan Tengah

Fusarium sp. is the fungus that causes Fusarium wilt, which has been
reported to cause significant damage at the nursery and plantation levels, to both
young and mature oil palm plants. Fusarium wilt can cause the death of more than
70% of the oil palm population and lead to production reductions of up to 80%. To
support biological control, previous exploratory research was conducted at PT
Mustika Sembuluh Wilmar International Plantation, Central Kalimantan, isolating
Trichoderma from five types of plantation soil (Histosol, Ultisol, Oxisol, Entisol,
and Spodosol), yielding five superior isolates (1H, 2H, 4H, 5H, and 1S). The current
research focus is directed at further testing the effectiveness of these five local
Trichoderma spp., isolates as effective biological control agents against Fusarium
sp. in vitro and analyzing their species identity based on molecular markers.
This research was conducted between November 2025 and March 2026. The
experimental phase, which included rejuvenation, dual culture antagonism testing,
and Volatile Organic Compounds (VOC) testing, was conducted in the mycology
laboratory of the Citra Widya Edukasi Palm Oil Polytechnic in Bekasi. The
subsequent molecular identification (DNA sequencing) phase was conducted at the
laboratory of PT Genetika Science Indonesia in Tangerang, Banten. The experiment
used a Completely Randomized Design (CRD). Molecular identification used
universal primers ITS1 and ITS4 to amplify the Internal Transcribed Spacer (ITS)
region of fungal ribosomal DNA. Sequence data were analyzed using the BLASTn
feature in the NCBI GenBank database, and phylogenetic tree reconstruction was
performed using the Neighbor-Joining method in the MEGA 11 application.
The antagonism test results showed that all Trichoderma spp. isolates from
Central Kalimantan had strong antagonistic activity against Fusarium sp. in vitro.
The T5 (Trichoderma 1S) treatment showed the highest effectiveness in the dual
culture test with an inhibition percentage of 61.62%. In the Volatile Organic
Compounds (VOC) test, all isolates were proven to be able to produce volatile
metabolites that inhibited the radial growth of Fusarium sp. with the T3
(Trichoderma 4H) treatment showing the highest inhibitory potential (18.19%) at 9
days after planting. The success of molecular DNA amplification was indicated by
the appearance of a single, thick, and clear DNA band measuring 564 bp. Based on
bioinformatics analysis and genetic similarity, the potential isolate 1S was
accurately identified as the species Trichoderma asperellum.