Scientific Profile
- Kingdom: Fungi
- Phylum: Ascomycota
- Genus: Fusarium
- Species: Fusarium oxysporum
Biological Role in Plants
1. Pathogenic Role:
- Invades the xylem vessels of host plants, leading to Fusarium wilt, causing:
- Leaf yellowing
- Wilting
- Stunting
- Plant death
- Produces toxic metabolites (e.g., fusaric acid) that interfere with plant physiology.
2. Agarwood Inoculant (Biotechnological Role):
- In the case of Aquilaria spp. (Agarwood trees), Fusarium oxysporum is purposefully inoculated to trigger stress responses, leading to resin production (agarwood formation).
- Used as part of biotic stress agents in inoculant technologies (e.g., BarIno FusaTrinity™).
- Mimics natural infection to induce secondary metabolite pathways, leading to resinous heartwood development.
Inoculation Techniques in Agarwood Cultivation
- Drill and fill method: A small hole is drilled into the trunk, and a spore suspension is injected.
- Soil drench or foliar application is not used for inoculation, as F. oxysporum needs direct contact with vascular tissues.
- Often combined with abiotic stressors (e.g., MnO₂ or NaCl) for enhanced resin production.
Identification
- Microscopic: Banana-shaped macroconidia, oval microconidia.
- Molecular: PCR and DNA sequencing using ITS and TEF1-alpha markers.
- Cultural: Grows on PDA (Potato Dextrose Agar) forming pinkish-white to violet colonies.
Safety & Risk Management
- While useful in agarwood resin induction, uncontrolled spread in plantations can:
- Infect non-target trees
- Contaminate soil
- Should be handled in contained, targeted applications only.
- Biocontrol fungi like Trichoderma spp. may be used to suppress its spread if needed.
Applications Summary
| Use Case | Benefit |
|---|---|
| Agarwood Resin Induction | Triggers resin formation for oud oil |
| Plant Pathology Research | Model for studying vascular wilt |
| Biocontrol Studies (as target) | Helps test antagonistic fungi |
| Genetic Engineering Host | Studied for its secondary metabolites |