Judul: Molecular Identification of Fungi and Genetic Diversity of Agarwood (Aquilaria spp.) in North Aceh District, Aceh Province, Molecular Identification of Fungi and Genetic Diversity of Agarwood (Aquilaria spp.) in North Aceh District, Aceh Province
Abstrak: Gaharu merupakan hasil hutan bukan kayu beraroma wangi berwarna gelap yang terbentuk akibat luka dari family Thymeleaceae jenis Aquilaria dan Gyrinops. Tiga faktor utama dalam pembentukan gaharu yaitu adanya tanaman yang berpotensi menghasilkan gaharu Aquilaria spp., adanya patogen tertentu (cendawan) dan lingkungan yang mendukung. Gaharu telah digunakan sebagai bahan baku industri parfum, kosmetik, upacara keagamaan, dan obat-obatan. Gaharu merupakan salah satu komoditi ekspor dan memiliki nilai jual yang sangat mahal. Negara penghasil gaharu hingga saat ini belum mampu memenuhi kebutuhan pasar dunia. Petani gaharu Indonesia saat ini telah berusaha keras untuk melakukan pemenuhan kebuthan pasar dengan teknik budidaya dan inokulasi. Beberapa spesies yang sedag digalakkan petani Indonesia adalah A. Malaccensis A. microcarpa, A. beccariana, A. hirta, Gyrinops versteegii, A. filaria dan A. cumingiana, A. subintegra dan A. crassna. Beberapa laporan telah dijelaskan bahwabanyak mikroba yang telah digunakan untuk induksi gaharu seperti Aspergillus spp., Penicillium, Fusarium, Lasiodiploidia, Chaetomium, Botryodiplodia spp. Diplodia spp., Fusarium bulbiferum, F. laterium, F. oxysporum, Pythium sp. danTrichoderma sp., dan Fusarium. Provinsi Aceh yang merupakan salah satu daerahprodusen gaharu alami di Indonesia, hingga saat ini belum ada laporan tentangidentitas jenis tanaman dan mikroba yang mampu menghasilkan gaharu dengankualitas super. Oleh karena itu perlu dilakukan karakterisasi dan identifikasiterhadap jenis tanaman dan cendawan penghasil gaharu yang ada di Provinsi Aceh. Tujuan penelitian adalah 1) untuk melakukan karakterisasi dan identifikasi tanaman penghasil gaharu yang ada di Provinsi Aceh; 2) untuk mengkarakterisasi dan mengidentifikasi cendawan penghasil gaharu yang ada di Provisi Aceh dan 3) melakukan pengujian cendawan terhadap tanaman penghasil gaharu yang ada di Provinsi Aceh. Materi genetik yang digunakan adalah 66 aksesi tanaman penghasil gaharu asal Provinsi Aceh untuk karakterisasi dan identifikasi tanaman penghasil gaharu, 100 bibit tanaman penghasil gaharu untuk uji tingkat virulensi dari cendawan hasil isolasi, karakterisasi dan identifikasi serta empat isolat cendawan penghasil gaharu yang diambil dari lokasi penelitian di Aceh. Tanaman penghasil gaharu yang digunakan merupakan tanaman yang tumbuh liar (bukan budidaya) yang ada dilokasi penelitian. Metode yang digunakan dalam penelitian ini meliputi survey lapangan dan uji laboratorium. Survey lapangan dilakukan untuk mengumpulkan data morfologi tanaman dan uji laboratorium dilakukan untuk mendapatkan data molekuler. Uji laboratorium dilakukan dengan menggunakan primer matK, ITS dan trnLtrnF untuk karakterisasi dan identifikasi tanaman penghasil gaharu, dan primer ITS digunakan untuk karakterisasi dan identifikasi cendawan penghasil gaharu. Karakterisasi morfologi dan molekuler dengan menggunakan marka matK, ITS dan trnL-trnF berhasil mengkarakterisasi dan mengidentifikasi tanaman penghasil gaharu asal Kabupaten Aceh Utara Provinsi Aceh. Hasil yang diperoleh adalah terdapat tiga jenis tanaman penghasil gaharu di lokasi penelitian di Aceh yaitu jenis Aquilaria malaccensis, Aquilaria beccarana dan Aquilaria microcarpa. Hasil karakterisasi dan identifikasi terhadap cendawan penghasil gaharu yang ditemukan di Kabupaten Aceh Utara adalah cendawan jenis Fusarium solani. Hasil uji lapangan pemberian cendawan Fusarium solani hasil isolasi dan identifikasi dapat menghasilkan gubal gaharu terhadap pohon Aquilaria microcarpa yang merupakan hasil identifikasi dalam penelitian ini. Hasil analisis GC-MS terhadap gubal yang dihasilkan akibat pemberian isolat dapat menghasilkan senyawa terpenoid dan kromon pada semua perlakuan dan pada perlakuan kontrol negatif hanya diperoleh senyawa terpenoid saja. Hal ini dapat disimpukan bahwa bahwa tanaman penghasil gaharu dan isolat asal lokasi penelitian dapat
Keyword: Aquilaria, Fusarium solani, Kromon, Provinsi Aceh, Terpenoid

Judul: Karakterisasi interaksi antara tanaman aquilaria microcarpa baill dengan fusarium solani dalam pembentukan gaharu
Abstrak: Aquilaria microcarpa is native to Indonesia and has been identified and promoted as potential tree species to yield high quality agarwood (gaharu). Individual trees of this species, both in its natural habitat and plantation, do not always yield agarwood due to many influencing factors. It is estimated that only 10% trees would be able to yield the resin. A clear mechanism of agarwood formation is unknown and there is a lack of information on underlying causes and triggers of the formation due to natural complexity and uncertainty. However, natural defense mechanisms through a series of pathogenesis are presumed as naturally observed in other resin producing tree species. Research on the characterization of host-pathogen interaction in gaharu formation was carried out based on the above mentioned problems with the following specific objectives, namely: i). to identify morphological characters of A. microcarpa trees interacting with F. solani sp, ii). to determine wood anatomical characters of A. microcarpa interacting with F. solani, and iii) to verify the genotypes of A. microcarpa seedlings and trees interacting with F.solani based on microsatellites. Results on tree morphological analysis showed that two out of 17 morphological characters (descriptor), namely tree height (m) and branching angles (0), showed significant differences between inoculated and non-inoculated individuals. In addition, microscopic observations on wood anatomical characters of A. microcarpa revealed that inoculated plants clearly deposited golden-brown colored resin in pores and canticles with a distinct scent. Further verification using GC MS on the sediment deposits identified common compounds as reported in many previous research on agarwood, namely: baimuxinal, elemol, 3-phenyl-2-butanone and chromone-3-one. On the other hand, tests on the viulence degrees of F. solani showed that one out of 4 strains, i.e. F.solani FORDA 512, showed the highest level of virulence and was significantly different with other F.solani, especially if inoculated on seedlings A60, A68 and B30. Two microsatellite loci of A. crassna, i.e. 6Pa18 and 71Pa17, were successfully transferable to A. microcarpa and could be used to characterize the genotypes of Fusarium-treated seedlings (n=40), inoculated trees (n=20) and non-inoculated trees (n=20). There were differences in terms of genetic structures between tree population and seedling population. Further sequence analysis on the microsatellite fragments on the most virulent F.solani FORDA 512- inoculated seedlings indicated genotype dependant responses for both seedling and tree stages. In addition, Sequence based cladogram showed that inoculated seedlings were closely placed with inoculated trees indicating certain genetic roles in the agarwood formation. In conclusion, tree morphological (i.e. height growth and branch habit) as well as genetic and genomic characters were clearly observed and useful to provide early information on gaharu formation. It is also supported by the wood anatomy analysis showing the presence of gaharu resin.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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