An assessment of genetic variation in vulnerable Borneo Ironwood Eusideroxylon zwageri Teijsm. & Binn. in Sarawak using SSR markers

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Siti Fatimah Md-Isa
Christina Seok Yien Yong
Mohd Nazre Saleh
Rusea Go


Borneo Ironwood Eusideroxylon zwageri Teijsm. & Binn. has high market value for its valuable and durable timber, which has put it at risk due to illegal logging.  This study analysed E. zwageri genetic variation using four microsatellite markers in populations at Nirwana Rehabilitation Forest (NRF), and Tatau, Sarawak.  We found that 20.1% of total genetic variation corresponded to differences between populations, while 79.9% was attributed to differences among individuals from the same population.  The Tatau population had lower genetic diversity compared to NRF, and both populations showed depressed heterozygosity indicative of inbreeding.  Allelic data were also used to confirm variety level differences proposed by earlier workers, and three informal varieties: zwageri, grandis, and exilis were recognized in the study area.  It is expected that the results from this study could serve as baseline data for conservation of this vulnerable species.

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Asian Regional Workshop (Conservation & Sustainable Management of Trees, Viet Nam, August 1996) (1998). Eusideroxylon zwageri. The IUCN Red List of Threatened Species 1998: e.T31316A9624725. Downloaded on 08 May 2021.

Avise, J.C. (2004). Molecular markers, natural history, and evolution. 2nd edition. Sinauer Associates, Sunderland, Massachusetts, 684pp.

Borsa, P., M. Zainuri & B. Delay (1991). Heterozygote deficiency and population structure in the bivalve Ruditapes decussatus. Heredity 86: 1–8.

Castric, V., L. Bernantchez, K. Belkhir & F. Bonhomme (2002). Heterozygote deficiencies in small lacustrine populations of brook charr Salvelinus fontinalis Mitchill (Pisces, Salmonidae): a test of alternative hypotheses. Heredity 89: 27–35.

Dharmarajan, G., W.S. Beatty & O.E. Rhodes Jr. (2012). Heterozygote deficiencies caused by a Wahlund effect: Dispelling unfounded expectations. The Journal of Wildlife Management 77(2): 226–234.

Doyle, J. J. & J.L. Doyle (1987). A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochem Bulletin 19: 11–15.

Finlay, C.M.V., C.R. Bradley, S.J. Preston & J. Provan (2017). Low genetic diversity and potential inbreeding in an isolated population of alder buckthorn (Frangula alnus) following a founder effect. Scientific Report 7(3010): 1–8.

Gauli, A., O. Gailing, V.M. Stefenon & R. Finkeldey (2009). Genetic similarity of natural populations and plantations of Pinus roxburhii sarg. In Nepal. Annuals of Forest Sciences 66: 703.

Global Trees Campaign (2020). Ironwood. Accessed on 20 February 2020.

Goudet, J. (1995). FSTAT (version 1.2). a computer program to calculate F- statistics. Journal of Heredity 86(6): 485–486.

Guries, R.P. & F.T. Ledig (1981). Genetic structure of populations and differentiation in forest trees. General Technical Report PSW-GTR-48. Berkeley, CA: Pacific Southwest Forest and Range Exp. Stn, Forest Service, U.S. Department of Agriculture, 42–47pp.

Harkingto, A. Purwantoro, D. Prajitno & A. Widyatmoko (2006). Genetic Variation of five ironwood populations in East Kalimantan revealed by RAPD marker. Ilmu Pertanian 13(1): 1–10.

Hilderbrand, C.E., D.C. Torney & R.P. Wagner (1994). Informativeness of polymorphic DNA markers, pp. 100–102. In: Cooper, N.G. (ed.). The Human Genome Project: Deciphering The Blueprint of Heredity. Universiti Science Books, Mill Valley, California, 360pp.

Hong, T.S. (2005). Identification of genomic markers for Belian using RAPD. Bachelor Degree Thesis. Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, vii+47pp.

IUCN-International Union for Conservation of Nature (2019). The IUCN Red List of Threatened Species. Eusideroxylon zwageri (Version 2019.2). Downloaded on January 20, 2019.

Irawan, B. (2005a). Bulian (Eusideroxylon zwageri Teijsm. & Binn.) sebagai salah satu komoditi unggulan di propinsi Jambi. Jurnal Agronomi 9(1): 49–54. (In Indonesian).

Irawan, B. (2005b). Ironwood (Eusideroxylon zwageri Teijsm. & Binn.) and its varieties in Jambi, Indonesia. Cuvillier Verlag. Inhaberin Annette Jentsch-Cuvillier, Nonnenstieg 8, 37075 Göttingen, Germany, 156pp.

Irawan, B. (2016). Physical and mechanical properties of four varieties of Ironwood. Journal of Tropical Wood Science and Technology 14(2): 175–182.

Irawan, B., F. Gruber, R. Finkeldey & O. Gailing (2016). Linking indigenous knowledge, plant morphology, and molecular differentiation: the case of ironwood (Eusideroxylon zwageri Teijsm. et Binn.). Genetic Resources Crop Evolution. 63: 1297–1306.

Johnston, H.R., B.J.B. Keats & S.L. Sherman (2019). Population Genetics, pp. 359–373. In: David, R., R. Pyeritz & B. Korf. Emery and Rimoin’s Principles and Practice of Medical Genetics and Genomics (6th ed.). Academic Press, 4,700pp.

Keats, B.J.B. & S.L. Sherman (2013). Population Genetics, pp. 1–12. In: David, R., R. Pyeritz & B. Korf. Emery and Rimoin’s Principles and Practice of Medical Genetics and Genomics (6th edition). Academic Press, 4,700pp.

Koopman, M.J.F. & L. Verhoef. (1938). Eusideroxylon zwageri, the ironwood of Borneo and Sumatra. Tectona 31: 381–399.

Kostermans, A.J.G.H., B. Sunarno, A. Martawijaya & S. Sudo. (1994). Eusideroxylon zwageri Teijsm. & Binn., pp. 211–215. In: Soerianegara, I. & R.H.M.J. Lemmens (eds.). Plant resources of South-East Asia. Timber trees: major commercial timbers PROSEA. Bogor, Indonesia, 610pp.

Kurokawa, H., T. Yoshida, T. Nakamura, J. Lai & T. Nakashizuka (2003). The age of tropical rain-forest canopy species. Borneo ironwood (Eusideroxylon zwageri), determined by 14C dating. Journal of Tropical Ecology 19(1): 1–7. https://doi:10.1017/S0266467403003018

Kurokochi, H., E. Tan, S. Asakawa, Sukartiningsih, Y. Saito & Y. Ide (2014). Development of 16 microsatellite markers in Eusideroxylon zwageri by next-generation sequencing. Conservation Genetic Resources 6: 593–595.

Lowe, A.J., D. Boshier, M. Ward, C.F.E. Bacles & C. Navarro (2005). Genetic resource impacts of habi-tat loss and degradation; reconciling empirical evidence and predicted theory for neotropical trees. Heredity 95: 255–273.

Md-Isa, S.F. (2020). Morphological and genetic variation of Eusideroxylon zwageri Teijsm. & Binn. (Borneo Ironwood) in Sarawak and fungi isolated from their fruits. PhD Thesis. Faculty of Science, Universiti Putra Malaysia, xvi+109pp.

Md-Isa, S.F., M.N., Saleh, C.S.Y., Yong, R. Jalonen & R. Go (2021). Utilization of historic herbarium collections as an indicator of the occurrence of Bornean ironwood in Sarawak, Malaysia. Malayan Nature Journal 73(1): 105–111.

Mostacedo, B., F.E. Putz, T.S. Fredericksen, A. Villca & T. Palacios (2009). Contributions of root and stump sprouts to natural regeneration of a logged tropical dry forest in Bolivia. Forest Ecology and Management 258(6): 978–985.

Nurtjahjaningsih, I.L.G., Sukartiningsih, H. Kurokochi, Y. Saito & Y. Ide. (2017a). Genetic structure of the tropical tree Eusideroxylon zwageri in Indonesiea revealed by chloroplast DNA phylogeography. Forest 8(7): 229.

Nurtjahjaningsih, I.L.G., Sukartiningsih, S., Saranti, A.P.A., Sulistyawati, P., & A. Rimbawanto (2017b). Kekerabatan genetik anakan alam Ulin (Eusideroxylon zwageri Teijsm. & Binn.) menggunakan penanda random amplified polymorphism DNA. Jurnal Pemuliaan Tanaman Hutan 11(1): 25–32. (In Indonesian).

Pandey, M., O. Gailing, L. Leinemann & R. Finkeldey (2004). Molecular markers provide evidence for long-distance planting material transfer during plantation establishment of Dalbergia sissoo Roxb. In Nepal. Annals of Forest Science 61(6): 603–606.

Peakall, R. & P.E Smouse (2012). GenAlex 6.5: genetic analysis in Excel. Population genetic software for teaching and research-an update. Bioinformatics 28(19): 2537–2539.

Perrier, X. & J.P. Jacquemoud-Collet (2006). DARwin. Available online:

Promega (2020). How do I determine the concentration, yield and purity of a DNA sample?. Accessed on 25 November 2020.

Rimbawanto, A., A.Y.P.B.C. Widyatmoko & Harkingto (2006). Population diversity of Eusideroxylon zwageri in East Kalimantan revealed by RAPD markers. Jurnal Penelitian Hutan Tanaman 3(3): 201–208.

Siew, Y.A. (2005). Genotyping of Eusideroxylon zwageri Teijsm & Binn. and Potoxylon melagangai Kosterm. (Borneo Ironwood) by using M13 universal primer. Bachelor Degree Thesis. Faculty of Resource Science and Technology, Universiti Malaysia Sarawak. vii+57pp.

Teijsmann, J.E. (1858). Botanische reis over banka en in de palembansche binnenlanden. Natuurkundig tijdschrift voor Nederlandsch-Indie. 96pp.

Teijsmann, J.E. & S. Binnendijk. (1863). Translation versoin of Bijdrage tot de kennis can het Echte Ijerhout (Eusideroxylon zwageri T. et B.). Natuurkundig tijdschrift voor Nederlandsch-Indie 25: 288–294.

Waples, R.S. (2015). Testing for Hardy-Weinberg proportions: have we lost the plost?. Journal of Heredity 106(1): 1–19.

Wright, S. (1931). Evolution in Mendelian populations. Genetics 16(2): 97–159.

Wright, S. (1978). Evolution and the genetics of populations, Vol. 4: Variability within and among natural populations. University of Chicago Press, Chicago, IL., 590pp.

Yoon, C.M. (2006). Genotyping of Eusideroxylon zwageri Teijsm & Binn. and Potoxylon melagangai Kosterm. (Borneo Ironwood) using DAMD markers. Bachelor Degree Thesis. Faculty of Resource Science and Technology, Universiti Malaysia Sarawak. ix+55pp.