Induction of Agarwood Formation by Combination of Acremonium and Chemical Treatments

Abstract

Agarwood is an aromatic resin produced by Aquilaria spp. The resin was formed as a response to fungal infection, mechanical damage or chemical treatment. This research was aiming at evaluation of the effectivity of single induction agent (salicylic acid (A), methyl jasmonate (M), Acremonium (F)) and in comparison to combination of induction agents. Trunks of Aquilaria crassna (±10 years old) was induced by either a single induction agents (A, M or F) or its combination (AF, AM, MF or AMF). Acremonium was given as pellets, while A and M were given at 100 mM and 750 mM, respectively. The tree was first drilled (4 mm diam. and one third diameter of the stem), with 20 cm distance between holes. The trunk was then injected with A, subsequently with M and inoculated with F, with a week interval of teratments. Agarwood quality criteria such as wood discoloration, fragrance level, and also terpenoid accumulation were observed monthly for four months periode. The results indicated that intensity of wood discoloration of all treatments ranges from brownish white to dark brown with AMF combination gave highest intensity. Fragrance did not induce by all treatments with AMF combination given highest mean score, but on the base at percentage of point induction, MF and F were more effective to induce fragrance. All of treatments induced terpenoids formation. AM and F treatments induced high triterpenoid accumulation with concentration 268.25 ppm. Wood discoloration was not correlated with fragrance level, but it was correlated with terpenoid accumulation. AMF stimulated wood discoloration and its fragrance level was better than the other treatments. However, only MF and F were effective to induce spesific agarwood fragrance.

Gaharu atau gubal gaharu (agarwood, eaglewood, aloeswood) merupakan hasil hutan bukan kayu yang berupa damar wangi (aromatik resin) dari pohon Aquilaria spp. dan genus lain dari Thymeleaceae. Gaharu digunakan sebagai bahan dasar dalam industri parfum, dupa untuk berbagai ritual keagamaan, kosmetik dan obat-obatan. Senyawa gaharu terbentuk sebagai respon pertahanan pohon gaharu terhadap berbagai gangguan seperti gangguan fisik, infeksi patogen, atau perlakuan kimiawi. Di antara molekul-molekul sinyal yang terlibat di dalam mengaktifkan respons pertahanan adalah asam salisilat, jasmonat, metil jasmonat, etilen, hidrogen peroksida dan superoksida radikal. Penelitian ini bertujuan untuk mengetahui efektivitas penginduksi tunggal asam salisilat, metil jasmonat (MeJA) dan Acremonium sp. serta kombinasinya. Penginduksi asam salisilat (A), MeJA (M) dan Acremonium sp. IPBCC07525 (F) diberikan secara tunggal atau kombinasinya pada batang A. crassna berukuran 20 cm (diam), umur 10 tahun. Penginduksi tunggal terdiri dari A, M atau F, kombinasi ganda terdiri dari AM, AF dan MF, sedangkan kombinasi tiga penginduksi yaitu AMF. Penginduksi pertama diberikan sesaat setelah pelubangan. Penginduksi kedua diberikan 1 minggu setelah penginduksi pertama dan penginduksi ke tiga diberikan 1 minggu setelah penginduksi kedua. Batang yang hanya dibor dijadikan kontrol. Pengamatan dilakukan terhadap gejala pembentukkan gubal gaharu (perubahan warna kayu dan tingkat wangi) serta kandungan terpenoidnya. Percobaan dilakukan dalam Rancangan Acak Lengkap dan diolah dengan SAS.