Judul: Endophytic fungi of wild zingiberaceae from Mount Halimun Salak National Park
Abstrak: The genus Colletotrichum, Diaporthe and Guignardia can live as plant pathogens on a wide variety of tropical woody, herbaceous and graminicoulos plants as well as fungal endophytes of many healthy plants. These two life styles are apparently caused by their biotrophic life strategies as such that they live as symptomless endophytes of living plant tissues. The species in Colletotrichum, Diaporthe and Guignardia have been reported to cause serious diseases in various economic plants in Indonesia. The exploration of these fungal endophytes was mainly done on economic plants. Those from non-cultivated plants in natural habitats are much less studied, with most studies being of endophytic strains. No reports are found on fungal endophyte from wild Zingiberaceae plant, therefore it is necessary to conduct research on the endophytic fungi on Zingiberaceae in order to provide information related fungal endophyte of wild Zingiberaceae in Indonesia. All fungal species recorded from Indonesia were mostly identified based on morphological characters. In this research, isolates of the fungal endophyte was collected by conventional isolation method. The isolates were then identified molecularly based on their ITS1F-ITS4 sequence. These sequences were aligned with MAFFT online. Phylogenetic analyses with all reference strains were performed using MEGA5 to produce the phylogram. The position and bootstrap value for branch support became the criteria of naming the isolates. Eleven isolates of fungal endophytes were obtained from different part of four species of Zingiberaceae at Mount Halimun Salak National Park (MHSNP) namely Alpinia malaccensis, Ammomum gracile, Etlingera punicea and Zingiber odoriferum. These consisted of nine isolates of Colletotrichum spp., one each isolate of Diaporthe infecunda and Guignardia mangiferae. Three of Colletotrichum isolates were belong to gloeosporioides clade, and six others were separate and made its own clade. The Colletotrichum species distributed widely on those four plant species at different plant part, one isolate of Colletotrichum kahawae subsp. kahawae from root of Etlingera punicea, one isolate of Colletotrichum aff. siamense from root of Alpinia malaccensis, and seven isolates of unidentified Colletotrichum species either from root of Alpinia malaccensis, pseudostem and leaf of Ammomum gracile, and from root of Zingiber odoriferum. One isolate of Diaporthe infecunda was from pseudostem of Alpinia malaccensis and one isolate Guignardia mangiferae was from pseudostem of Zingiber odoriferum. All of this finding is new records on fungal endophytes from wild species of Zingiberaceae and may contribute to the management of domestication of these plants.
Keyword: endophyte, ITS, Zingiberaceae

Judul: Keragaman cendawan endofit yang diisolasi dari berbagai spesies tanaman obat potensial
Abstrak: Indonesia has high medicinal plant diversity, however, there was limited study on endophytic fungi associated with them, particularly on potential medicinal plant jahe merah (Zingiber officinale Roscoe), jati belanda (Guazuma ulmifolia Lamk), local pegagan (Centella asiatica L), malaysian pegagan, and temulawak (Curcuma xanthorrhiza Roxb). As traditional medicines, the society use certain medicinal plant organ such as leaf, stem, rhizome and root as functional organ in traditional remedy because it contains high bioactive compounds. Some endophytic fungi had been reported to produce bioactive compound including anti-microbe substances. Role of endophytic fungi in production of bioactive compound of medicinal plant as their host is significant, however, diversity and distribution of the fungi in the host plant are not sufficiently studied particularly for the five potential medicinal plant mention above. The aims of the research were: 1). To obtained the endophytic fungi isolates from the functional organ of jati belanda, local pegagan and malaysian pegagan type, and jahe merah, and from whole of jahe merah plant organs, 2). To study the diversity of endophytic fungi by using a combination of morphological characteristic, molecular analysis of sequence DNA generated from ITS rDNA region, and chemistry characteristic by FTIR, 3). To study the potency of endophytic fungi which have activity as biological control against F. oxysporum. The medicinal plants used were divided into two groups. The first group was medicinal plants that used only their functional organ that is leaf of jatibelanda, leaf of local pegagan and malaysian pegagan, and rhizome of temulawak. The second group was jahemerah plant. In this group all plant organs both functional and non-functional such as leaf, stem, rhizome and root were used as source of fungal isolation. In the first group, all functional organ of plants studied harbored endophytic fungi. There were 13 isolates of the endophytic fungi obtained from leaf of jati belanda and each of leaves of pegagan local and malaysian cultivars, and rhizome of jahe merah was occupied by five isolates. The fungi were identified as Aspergillus versicolor, Aspergillus sydowii, Aspergillus terreus, Colletotrichum gloeosporioides and its teleomorphic stage Glomerella cingulata, Colletotrichum higginsianum, Curvularia affinis, Diaporthe phaseolorum, Engyodontium album, Fusarium solani, Lasiodiplodia theobromae, Leptosphaerulina australis, Mycoleptodiscus indicus, Pseudocercospora cruenta, Stagonosporopsis cucurbitacearum, Talaromyces assiutensis. Colletotrichum gloeosporioides and its teleomorphic stage Glomerella cingulata were dominant endophyte fungi and were found in all plants study. Endophytic fungi derived from functional organ of jati belanda, temulawak, pegagan local and malaysian cultivars had inhibitation activity against F. oxysporum with the ranges of inhibition value 6.0-78.9%. Talaromyces trachyspermus JBd10, Glomerella cingulata JMr2, and Fusarium solani JMd14 statistically had the highest inhibitation value, while Mycoleptodiscus indicus PMd1 and Engyodontium album JBd13 had the lowest inhibitation value. Thirty isolates of endophytic fungi having different colony characteristics were obtained from Zingiber officinale, six isolates were derived from functional organ of Zingiber officinale and twenty four isolates were derived from nonfunctional organ of Zingiber officinale, i.e. leaf, rhizome, root, and stem. Each of root, stem, and leaf was occupied by eight isolates. Fungal identification by using a combination of morphological characteristic, molecular analysis of sequence DNA generated from ITS
Keyword: medicinal plants, endophitic fungi, diversity, identification, phylogenetic, chemistry analisis

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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