Use of two fungal species to induce agarwood resin formation in Gyrinops walla

Abstract

Gyrinops walla Gaertn. is the only species growing in Sri Lanka that belongs to the agarwood family, Thymelaeaceae. Although agarwood resin induction and extraction from Aquilaria species of the same family have been practised for many decades in Southeast Asian region, the ability of producing agarwood resins in G. walla was discovered recently. Since previous studies were on agarwood resins formed due to natural causes, the present study was conducted to identify the potential fungal species that are capable of artificially inducing agarwood resin formation in G. walla. Since this is the first ever study conducted on artificial inducement of agarwood resin formation in G. walla, Aspergillus niger and Fusarium solani were selected owing to their high abundance in the naturally formed agarwood resinous tissues collected from 25 G. walla trees. Both fungal species were separately grown in yeast extract glucose agar and used to inoculate healthy G. walla trees under aseptic conditions. Three holes were made for each tree and 2 g of fungal culture including the medium were placed in each hole. Tissue discoloration, characteristic aroma, resin content and resin constituents were checked at 10 cm intervals above and below the inoculation points for a period of 1 year. Results revealed that tissue discoloration and resin content were higher in the trees inoculated with A. niger. Other than at 10 cm above and below the inoculation points, samples collected at all locations had significantly higher resin contents when inoculated with A. niger compared to F. solani. Sixteen agarwood resin constituents, which were also recorded in Aquilaria species, were identified from the discolored tissues using GC–MS analysis. Jinkohol, agarospirol and 2(2-phenyl) chromone derivatives were found in all discolored tissues collected at 10-cm intervals of the trees inoculated with both fungi. β-Seline, γ-eudesmol and valerenal were found in nine of 10 sample points on the stem. γ-Elemene was recorded only in one sample. The characteristic aroma during burning was stronger for dark-colored tissues than the light-colored ones. The present study confirmed the potential use of certain fungal species to induce agarwood resin in G. walla and that A. niger is more effective than F. solani.

Keywords

Gyrinops walla / Agarwood resin / Aspergillus niger / Fusarium solani / Inoculation

References

[1] Akter S, Islam MT, Zulkefell M, Khan SI. Agarwood production: a multidisciplinary field to be explored in Bangladesh. Int J Pharm Life Sci, 2013, 2(1): 22-32.

[2] Barden A, Noorainie AN, Teresa M, Michael S. Heart of the matter: Agarwood use and trade and CITES implementation for Aquilaria malaccensis, 2000, Cambridge: IUCN Publication, Traffic International.

[3] Blanchette RA (2003) Agarwood formation in Aquilaria trees: resin production in nature and how it can be induced in plantation grown trees. In: Notes from presentation at first international agarwood conference, Ho Chi Minh City, Vietnam, pp 10–15

[4] Munsell Soil Color Charts (1994) Revised edn. Macbeth Division of Kollmorgen Instruments Corporation, New York

[5] Chen H, Yang Y, Xue J, Wei J, Zhang Z, Chen H. Comparison of compositions and antimicrobial activities of essential oils from chemically stimulated agarwood, wild agarwood and healthy Aquilaria sinensis (Lour.) Gilg trees. Molecules, 2011, 16: 4884-4896.

[6] Chen HQ, Wei JH, Yang JS, Zhang Z, Yang Y, Gao ZH, Sui C, Gong B. Chemical constituents of agarwood originating from the endemic genus Aquilaria plants. Chem Biodivers, 2012, 9(2): 236-250.

[7] Chong SP, Osman MF, Bahari N, Nuri EA, Zakaria R, Abdul-Rahim K. Agarwood inducement technology: a method for producing oil grade agarwood in cultivated Aquilaria malaccensis Lamk. J Agrobiotechnol, 2015, 6: 1-16.

[8] Cui J, Guo S, Fu S, Xiao P, Wang M. Effects of inoculating fungi on agilawood formation in Aquilaria sinensis. Chin Sci Bull, 2013, 58(26): 3280-3287.

[9] Dassanayake MD, Fosberg FR. Flora of Sri Lanka, 1981, New Delhi: IBH Publishing Company.

[10] Jensen A Bouhom Domestication of Aquilaria spp. and rural poverty-socio-economic and genetic aspects of the planting boom in the wood of gods. Poverty reduction and shifting cultivation stabilization in the uplands of Lao PDR: technologies, approaches and methods for improving upland livelihood, 2005, Vientiane: National Agriculture and Forestry Research Institute 233 239

[11] Karlinasari L, Indahsuary N, Kusumo HT, Santoso E, Turjaman M, Nandika D. Sonic and ultrasonic waves in agarwood trees (Aquilaria microcarpa) inoculated with Fusarium solani. J Trop For Sci, 2015, 27(3): 351-356.

[12] Laurence WVA (2013) Isolation and characterization of endophytes isolated from Akar Gaharu. Research Dissertation, Universiti Malaysia Sarawak, Malaysia

[13] Mei W, Yang D, Wang H, Yang J, Zeng Y, Guo Z, Dong W, Li W, Dai H. Characterization and determination of 2-(2-phenylethyl) chromones in agarwood by GC–MS. Molecules, 2013, 18(10): 12324-12345.

[14] Mohamed R, Jong PL, Zali MS. Fungal diversity in wounded stems of Aquilaria malaccensis. Fungal Divers, 2010, 43: 67-74.

[15] Mohamed R, Jong PL, Kamziah AK. Fungal inoculation induces agarwood in young Aquilaria malaccensis trees in the nursery. J For Res, 2014, 25(1): 201-204.

[16] Ng LT, Chang YS, Kadir AA. A review on agar (gaharu) producing Aquilaria species. J Trop For Prod, 1997, 2: 272-285.

[17] Nor Azah MA, Chang YS, Mailina J, Abu Said A, Abdul Majid J, Saidatul Husni S, Nor Hasnida H, Nik Yasmin Y. Comparison of chemical profiles of selected gaharu oils from Peninsular Malaysia. Malays J Anal Sci, 2008, 12(2): 338-340.

[18] Okudera Y, Ito M. Production of agarwood fragrant constituents in Aquilaria calli. Plant Biotechnol, 2009, 26(3): 307-315.

[19] Persoon GA. Agarwood: the life of a wounded tree. IIAS Newsl, 2007, 45: 24-25.

[20] Subasinghe SMCUP, Hettiarachchi DS. Agarwood resin production and resin quality of Gyrinops walla Gaertn. Int J Agric Sci, 2013, 3(1): 357-362.

[21] Subasinghe SMCUP, Hettiarachchi DS. Characterization of agarwood type resin of Gyrinops walla Gaertn growing in selected populations in Sri Lanka. Ind Crops Prod, 2015, 69: 76-79.

[22] Subasinghe SMCUP, Hettiarachchi DS, Rathnamalala E. Agarwood-type resin from Gyrinops walla Gaertn: a new discovery. J Trop For Environ, 2012, 2(2): 44-49.

[23] Tabata Y, Widjaja E, Mulyaningsih T, Parman I, Wiriadinata H, Mandang YI, Itoh T. Structural survey and artificial induction of aloes wood. Bull Wood Res Inst Kyoto, 2003, 90: 11-12.

[24] Tamuli P, Boruah P, Nath SC, Leclercq P. Essential oil of eaglewood tree: a product of pathogenesis. J Essent Oil Res, 2005, 17(6): 601-604.

[25] Tian JJ, Gao XX, Zhang WM, Wang L, Qu LH. Molecular identification of endophytic fungi from Aquilaria sinensis and artificial agarwood induced by pinholes-infusion technique. Afr J Biotech, 2013, 12(21): 3115-3131.

[26] Wetwitayaklung P, Thavanapong N, Charoenteeraboon J. Chemical constituents and antimicrobial activity of essential oil and extracts of heartwood of Aquilaria crassna obtained from water distillation and supercritical fluid carbon dioxide extraction. Silpakorn Univ Sci Technol J, 2009, 3(1): 25-33.

[27] Zhang XL, Liu YY, Wei JH, Yang Y, Zhang Z, Huang JQ, Chen HQ, Liu YJ. Production of high-quality agarwood in Aquilaria sinensis trees via whole-tree agarwood-induction technology. Chin Chem Lett, 2012, 23: 727-730.