Judul: Pertumbuhan Kentang Kultivar Atlantik Transgenik dan Non-transgenik yang Diinokulasi Bakteri Endofit Micrococcus endophyticus
Abstrak: Gen LYZ-C penyandi enzim lisozim telah diintroduksikan ke dalam tanaman kentang (kultivar Atlantik) dan menghasilkan tanaman transgenik, diantaranya ATT1 dan ATT4. Kedua tanaman transgenik tersebut mengekspresikan gen lisozim secara konstitutif yang menjadikannya resisten terhadap bakteri fitopatogen Ralstonia solanacearum dan Pectobacterium carotovorum. Lisozim merupakan enzim pendegradasi dinding sel bakteri sehingga bakteri menjadi lisis. Bakteri endofit Micrococcus endophyticus G053 mengkolonisasi tabung xilem dan meningkatkan pertumbuhan tanaman kentang. Penelitian ini bertujuan untuk membandingkan pertumbuhan tanaman kentang kultivar Atlantik transgenik yang mengandung gen LYZ-C dan tanaman non-transgenik yang diinokulasi dengan bakteri endofit M. endophyticus G053 secara in vitro. Perbandingan pertumbuhan kedua jenis tanaman tersebut dapat digunakan untuk mengetahui pengaruh tanaman transgenik yang mengandung gen LYZ-C terhadap bakteri endofit M. endophyticus. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan satu faktor perlakuan yaitu genotipe yang terdiri dari tiga klon tanaman yang meliputi satu klon kentang kultivar Atlantik non-transgenik dan dua klon transgenik yaitu ATT1 dan ATT4. Pengamatan pertumbuhan tanaman yang dilakukan meliputi tinggi batang, jumlah buku, jumlah akar, dan panjang akar. Hasil penelitian menunjukkan bahwa pertumbuhan tinggi batang, jumlah buku, panjang akar, dan jumlah akar dari tanaman kentang non-transgenik dan kentang transgenik yang diinokulasi oleh M. endophyticus tidak berbeda nyata. Hasil reisolasi Micrococcus endophyticus G053 dari tanaman transgenik dan non-transgenik mengindikasikan bahwa keberadaan dan ekspresi gen LYZ-C pada tanaman transgenik tidak menyebabkan kematian bakteri endofit tersebut., LYZ-C gene encoding lysozyme was introduced into potato plant (Atlantic cultivar) producing transgenic plants i.e. diantaranya ATT1 dan ATT4. The two transgenic plants, express LYZ-C gene constitutively making them resistant to phytopathogenic bacteria, Ralstonia solanacearum and Pectobacterium carotovorum. Lysozymes are enzymes that degrade bacterial cell walls so that bacteria become lysis. Endophytic bacterium Micrococcus endophyticus G053 colonizes xylem tubes and increases the growth of potato plants. This study aims to compare the growth of transgenic Atlantic potato cultivars containing LYZ-C gene and non-transgenic plants inoculated with endophytic bacteria M. endophyticus G053 in vitro. The comparison of the growth of the two types of plants can be used to determine the effect of transgenic plants containing the LYZ-C gene on endophytic bacteria M. endophyticus. This study used a completely randomized design (CRD) with one treatment factor, namely a genotype consisting of three plant clones including one nontransgenic Atlantic potato cultivar clone and two transgenic clones namely ATT1 and ATT4. The growth of plant including stem height, number of books, number of roots, and root length was observed. The results showed that the growth of stem height, number of nodes, root length, and number of roots of non-transgenic and transgenic potatoes inoculated by M. endophyticus were not significantly different. Reisolation results of M. endophyticus G053 from the transgenic and non-transgenic plants indicated that the LYZ-C gene and its expression in the transgenic plants did not cause the death of the bacterium.
Keyword: endophytic bacteria, lysozyme, Micrococcus endophyticus, transgenic potato

Judul: Growth of Transgenic and Non-transgenic Jala Ipam Potato Inoculated by Endophytic Bacteria Micrococcus endophyticus G053
Abstrak: Tanaman kentang kultivar Jala Ipam transgenik JCL2 dan JCL3 mengekspresikan gen LYZ-C secara konstitutif di dalam sitosol sehingga resisten terhadap bakteri patogen, yaitu Ralstonia solanacearum dan Pectobacterium carotovorum subsp. carotovorum. Gen LYZ-C menyandi lisozim yang merusak dinding sel bakteri dengan cara memotong ikatan β-1,4 di antara N-asetil-D-muramat dengan N-asetil-D-glukosamin pada peptidoglikan sehingga dapat mengakibatkan lisisnya sel bakteri. Bakteri endofit Micrococcus endophyticus G053 dapat meningkatkan pertumbuhan tanaman kentang. Penelitian ini bertujuan untuk mengetahui pertumbuhan plantlet kentang kultivar Jala Ipam transgenik yang mengandung gen LYZ-C dan non-transgenik yang diinokulasi dengan bakteri endofit M. endophyticus G053 secara in vitro. Plantlet kentang kultivar Jala Ipam non-transgenik, JCL2, dan JCL3 yang diinokulasi dengan bakteri endofit M. endophyticus G053 secara in vitro, tidak menunjukkan perbedaan nyata dalam pertumbuhan tinggi batang, jumlah buku, panjang akar, dan jumlah akar. Reisolasi bakteri dari plantlet yang telah diinokulasi sebelumnya dengan M. endophyticus G053 dan dari hasil subkultur plantlet tersebut menunjukkan bahwa M. endophyticus G053 tidak mengalami kematian di plantlet transgenik. Hasil ini mengindikasikan bahwa gen LYZ-C yang terdapat di dalam tanaman kentang kultivar Jala Ipam transgenik JCL2 dan JCL3 yang diekspresikan secara konstitutif di dalam sitosol tidak mempengaruhi pertumbuhan dan perkembangan bakteri endofit M. endophyticus G053. Kata kunci: jumlah akar, jumlah buku, lisozim, panjang akar, tinggi batang, The transgenic potato cultivar Jala Ipam JCL2 and JCL3 expressed the LYZ-C gene constitutively in the cytosol so that it was resistant to pathogenic bacteria Ralstonia solanacearum and Pectobacterium carotovorum subsp. carotovorum. The LYZ-C gene encodes the lysozyme that damages cell walls of the bacteria by cutting the β-1,4 bonds between N-acetyl-D-muramate and N-acetyl-D-glucosamine of peptidoglycan resulting in bacterial cells lysis. Endophytic bacteria Micrococcus endophyticus G053 increases the growth of potato plants. This study aims to determine the growth of transgenic potato cv Jala Ipam plantlets containing the LYZ-C genes and non-transgenic one which were inoculated with endophytic bacteria Micrococcus endophyticus G053 in vitro. Non-transgenic Jala Ipam, JCL2, and JCL3 inoculated with endophytic bacteria M. endophyticus G053 in vitro, did not show significant differences in the growth of stem height, number of nodes, root length, and number of roots. The re-isolation of bacteria from the plantlets previously inoculated with M. endophyticus G053 and the results of the plantlet subcultures showed that M. endophyticus G053 did not die in the transgenic plantlets. These results indicated that the LYZ-C gene contained in the transgenic potato cultivar Jala Ipam, i.e. JCL2 and JCL3 which was expressed constitutively in the cytosol did not affect the growth and development of endophytic bacteria M. endophyticus G053. Keywords: lysozyme, number of nodes, number of roots, root length, stem height
Keyword: lysozyme, number of nodes, number of roots, root length, stem height

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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