Judul: Morphological, Growth and DNA Barcoding Studies for the Identification of the Genus Scindapsus
Abstrak: Scindapsus merupakan genera dari keluarga Araceae dan banyak ditemukan di hutan-hutan Indonesia. Scindapsus merupakan tanaman hias popular dan beberapa spesiesnya dapat dimanfaatkan sebagai tanaman obat, namun pemahaman tentang morfologi dan pertumbuhannya masih terbatas. Teknologi barcode DNA belum banyak dimanfaatkan dalam identifikasi spesies Scindapsus. Tujuan penelitian ini adalah untuk mengidentifikasi berbagai spesies Scindapsus berdasarkan karakteristik morfologi dan pola pertumbuhan, serta memanfaatkan analisis Penanda DNA untuk identifikasi. Berdasarkan morfologi daun Scindapsus dapat dikategorikan menjadi tiga kelompok: S. pictus, S. treubii, Scindapsus sp. Pertumbuhan tunas menunjukkan waktu yang dibutuhkan tanaman untuk menghasilkan lima daun terbuka penuh berkisar antara 16 hingga 20 minggu setelah tanam. Karakteristik pertumbuhan tunas baru menunjukkan bahwa S. pictus 1, 4, dan 5 ditutupi oleh cataphylls, tunas S. pictus 3 ditutupi oleh daun-daun belum terbuka sempurna, dan tunas S. pictus 2, S. treubii 1, dan 2 tidak tertutupi. Isolasi delapan sampel DNA Scindapsus menghasilkan konsentrasi lebih dari 100 ng/µL dengan nilai kemurnian mulai dari 1,9 hingga 2,2. Penanda rbcL dan trnH-psbA digunakan pada kedelapan sampel Scindapsus yang mampu mengamplifikasi dengan baik dan menghasilkan urutan DNA dengan panjang berkisar antara 748 – 756 bp dan 426 – 476 bp. Penanda matK digunakan pada kedelapan sampel Scindapsus, tetapi hanya tiga sampel yang disekuensing, hasil ukuran panjang basanya yaitu 944 bp untuk sampel S. pictus 3, 953 bp untuk sampel S. pictus 4 dan 940 bp untuk S. treubii 1. Penanda ITS pada sampel Scindapsus tidak berhasil mengamplifikasi DNA, sehingga tidak dapat diproses ke tahap sekuensing. Analisis data DNA barcoding diantaranya analisis kecocokan tingkat homologi menunjukkan berkerabat dekat antara sekuen tanaman Scindapsus dengan sekuen Epipremnum amplissimum untuk penggunaan penanda rbcL, sekuen Scindapsus dengan sekuen Monstera deliciosa untuk penggunaan penanda trnHpsbA, sekuen Scindapsus dengan sekuen Scindapsus rupestris untuk penggunaan penanda matK. Perubahan basa pada masing-masing sekuen DNA Scindapsus mencakup mutasi transisi dan transversi. Analisis filogenetik spesies Scindapsus yang diuji mengelompok dalam cabang yang sama dan membedakan dengan outgroup genus Scindapsus., Scindapsus is genera of the Araceae family and is widely found Scindapsus is a popular ornamental plant and some of its species can be utilised as medicinal plants. However, understanding of its morphology and growth is still limited. DNA barcode technology has not been widely utilised in the identification of Scindapsus species. The aim of this study was to identify various Scindapsus species based on morphological characteristics and growth patterns, and utilise DNA analysis for identification. Morphological based of the leaves of Scindapsus was categorised into three groups: S. pictus, S. treubii, Scindapsus sp. Shoot growth showed that the time required for plants to produce five fully opened leaves ranged from 16 to 20 weeks after planting. Growth characteristics of new shoots showed that S. pictus 1, 4, and 5 were covered by cataphylls, S. pictus 3 shoots were covered by incompletely opened leaves, and S. pictus 2, S. treubii 1, and 2 shoots were not covered. Isolation of Scindapsus DNA eight samples resulted in concentrations of more than 100 ng/µL with purity values ranging from 1.9 to 2.2. markers rbcL and trnHpsbA used on all eight Scindapsus samples amplified well and produced DNA sequences with
Keyword: Jawa Barat, Kalimantan Barat, penanda daerah kloroplas, penanda daerah inti sel, setek

Judul: Characterization Morphology, Agronomy, and  Phylogenetic Relationships of Scindapsus sp. from West Kalimantan
Abstrak: Scindapsus sp. merupakan tanaman hias daun yang 30 dari 60 spesiesnya berada di Indonesia, namun sebagian besar belum teridentifikasi. Penelitian ini bertujuan mengidentifikasi karakter morfologi daun, mempelajari pertumbuhan dan perkembangan tanaman, serta menganalisis hubungan kekerabatan beberapa jenis Scindapsus sp. asal Hutan Kapuas Hulu, Kalimantan Barat. Penelitian dilakukan pada bulan Mei hingga November 2022, dengan tiga tahap pengamatan, yaitu pengamatan morfologi dan pertumbuhan di greenhouse, pengamatan histologi daun di laboratorium, dan pengamatan pasca perbanyakan. Penelitian dilakukan pada tiga jenis Scindapsus, yakni Scindapsus sp. 1 (S. pictus ‘Platinum’), Scindapsus sp. 2 (S. pictus ‘Hassk’), dan Scindapsus sp. 3 (S. argyraeus ‘Black Exotica’). Hasil penelitian menunjukkan karakter morfologi, anatomi, dan pertumbuhan pada setiap jenis Scindapsus. Scindapsus sp. 1 (S. pictus ‘Platinum’) memiliki keragaan yang besar. Karakter warna dan corak daun menjadi ciri pembeda utama antar jenis. Ukuran palisade dan stomata selaras dengan pertumbuhan tanaman. Hubungan kekerabatan ketiga jenis scindapsus ditunjukkan oleh hasil bagan dendrogram berdasarkan beberapa parameter. Dendrogram Scindapsus sp. dengan kekerabatan paling dekat berdasarkan karakter warna dan corak daun, warna batang, kerapatan stomata serta rasio palisade daun adalah Scindapsus sp. 1 (S. pictus ‘Platinum’) dan Scindapsus sp. 2 (S. pictus ‘Hassk’), sedangkan berdasarkan karakter pertumbuhan tanaman yaitu pertambahan ruas dan daun, ukuran batang, ruas, dan daun menunjukkan Scindapsus sp. 2 (S. pictus ‘Hassk’) lebih dekat dengan Scindapsus sp. 3 (S. argyraeus ‘Black Exotica’)., Scindapsus sp. is a tropical foliage plant from the Araceae family, consisting of 60 species, 30 of which are found in Indonesia. However, most of these species have not been fully identified in terms of morphology and growth. The aim of this research is to identify leaf morphological characteristics, study plant growth and development, and analyze the phylogenetic relationships of several species of Scindapsus sp. from the Kapuas Hulu forest in West Kalimantan. The research was conducted from May to November 2022 and included three stages: morphological and growth observations in the greenhouse, histological observations in the laboratory, and post-propagation observations. The study focused on three cultivars of Scindapsus, namely Scindapsus sp. 1 (S. pictus ‘Platinum’), Scindapsus sp. 2 (S. pictus ‘Hassk’), and Scindapsus sp. 3 (S. argyraeus ‘Black Exotica’). The results showed the morphology and growth characteristics of each type of Scindapsus. The plant Scindapsus sp. 1 (S. pictus ‘Platinum’) had the largest size compared to the other cultivars. The color and pattern of the leaves were the main distinguishing features between the cultivars. The sizes of the palisade cells and stomata were compatible with the growth of the plants. The phylogenetic relationships between the cultivars were illustrated by a dendrogram chart based on several parameters. The dendrogram of Scindapsus sp. based on leaf color and pattern, stem color, stomata density, and palisade leaf ratio shows that Scindapsus sp. 1 (S. pictus ‘Platinum’) and Scindapsus sp. 2 (S. pictus ‘Hassk’) are most closely related. However, based on plant growth characteristics such as node and leaf increment, stem size, node length, and leaf size, Scindapsus sp. 2 (S. pictus ‘Hassk’) is closer to Scindapsus sp. 3 (S. argyraeus ‘Black Exotica’).
Keyword: characterization, histology, morphology, dendrogram, scindapsus

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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