Judul: Analysis of MmCu/Zn-SOD Gene Expression and Resistance of Transgenic Potato Cultivars IPB CP3 to Parakuat Herbicide
Abstrak: Penggunaan herbisida paraquat untuk mengendalikan pertumbuhan gulma telah menjadi metode yang paling umum. Namun penggunaan herbisida ini juga dapat menyebabkan kerusakan sel pada tanaman kentang yang sedang dibudidayakan karena herbisida paraquat dapat menginduksi terbentuknya senyawa Reactive Oxygen Species (ROS) yang dapat merusak sel tanaman. Ekspresi berlebih dari gen MmCu/Zn-SOD diharapkan dapat memberikan ketahanan terhadap cekaman herbisida paraquat. Penelitian ini bertujuan untuk menganalisis ekspresi gen MmCu/Zn-SOD pada kentang transgenik IPB CP3 kultivar dan ketahanannya terhadap cekaman herbisida paraquat. Perlakuan herbisida paraquat dengan konsentrasi 75 µM pada tanaman transgenik (P3SOD6, P3SOD9, P3SOD17) dan nontransgenik (NT) secara in vitro menunjukkan bahwa semua tanaman transgenik lebih tahan terhadap cekaman paraquat dibandingkan tanaman non-transgenik. Klon P3SOD9 paling tahan terhadap herbisida paraquat, dengan perbandingan 10 tanaman hidup dari 12 tanaman yang diuji. Ekspresi MmCu/Zn-SOD pada galur transgenik lebih tinggi dibandingkan galur non-transgenik. Ekspresi relatif gen MmCu/Zn-SOD pada P3SOD9 lebih tinggi 233,22 kali dibandingkan NT, P3SOD6 127,62 kali, dan P3SOD17 3,18 kali. Semakin tinggi ekspresi MmCu/ZnSOD berkorelasi dengan semakin tinggi ketahanan terhadap cekaman herbisida paraquat., The use of paraquat herbicides to control weed growth has become the most common method. However, using this herbicide can also cause cell damage in potato plants that are being cultivated because paraquat herbicide can form Reactive Oxygen Species (ROS) compounds that can damage cells from plants. Overexpression of the MmCu/Zn-SOD gene is expected to provide resistance to paraquat herbicide stress. This study aimed to analyze the expression of the MmCu/Zn-SOD gene in transgenic potato cultivar IPB CP3 and its resistance to paraquat herbicide stress. Paraquat herbicide treatment with a concentration of 75 µM on transgenic (P3SOD6, P3SOD9, P3SOD17) and non-transgenic (NT) plants in vitro showed that all transgenic plants were more resistant to paraquat stress than that of nontransgenic plants. The P3SOD9 clone was the most resistant to paraquat herbicide, with a ratio of 10 survive plants of the 12 plants tested. The expression of MmCu/Zn-SOD in transgenic lines was higher than in non-transgenic lines. The relative expression of MmCu/Zn-SOD gene in P3SOD9, P3SOD6, and P3SOD17 was 233.22, 127.62, and 3.18 times higher than that of NT, respectively. The expression level of MmCu/ZnSOD correlated with the level of resistance to paraquat herbicide stress.
Keyword: ekspresi gen, herbisida parakuat, MmCu/Zn-SOD

Judul: Resistance Analysis of Transgenic Potato Cultivar IPB CP3 Containing the MmCu/Zn-SOD Gene against Aluminum Stress and Low pH
Abstrak: Kelarutan aluminium (Al) yang tinggi dan pH rendah menjadi faktor pembatas pertumbuhan dan produksi tanaman kentang. IPB CP3 ialah kultivar kentang industri yang cocok untuk pembuatan keripik kentang dan french fries. Gen MmCu/Zn-SOD telah diintroduksi ke dalam kultivar IPB CP3 sehingga menghasilkan kentang transgenik yang tahan cekaman abiotik. Penelitian ini bertujuan menganalisis stabilitas transgen MmCu/Zn-SOD dan ketahanan kultivar IPB CP3 transgenik terhadap cekaman Al dan pH rendah secara in vitro. Percobaan dilakukan menggunakan rancangan acak lengkap (RAL), dua faktor perlakuan, dan empat ulangan. Faktor pertama yaitu genotipe kentang yang terdiri atas IPB CP3 non-transgenik dan empat klon transgenik (P3SOD3, P3SOD7, P3SOD10 dan P3SOD13). Faktor kedua yaitu cekaman Al dan pH rendah pada media tanam yang terdiri atas (1) pH 4+Al 2 mM, (2) pH 4 tanpa Al, dan (3) pH 5,8 tanpa Al (kontrol). Transgen MmCu/Zn-SOD di dalam genom tanaman IPB CP3 transgenik tetap stabil. Tingkat ketahanan klon transgenik terhadap Al dan pH rendah bervariasi. Klon P3SOD3 dan P3SOD10 mempunyai tingkat ketahanan paling tinggi terhadap cekaman Al dan pH rendah., The high solubility of aluminum (Al) and low pH is a limiting-factors for growth and can reduce plant productivity. IPB CP3 is an industrial potato suitable for the manufacture of potato chips and french fries. IPB CP3 cultivar potato was introduced with the MmCu/Zn-SOD gene resulting in abiotic stress resistant transgenic potatoes. This study aims to analyze the stability of the MmCu/Zn-SOD transgene in transgenic IPB CP3 potato cultivars and their resistance to Al stress and low pH in vitro. The experiment was conducted using a completely randomized design (CRD), two treatment factors, and four replications. The first factor was the potato genotypes consisting of non-transgenic IPB CP3 and four transgenic clones (P3SOD3, P3SOD7, P3SOD10, and P3SOD13). The second factor was the Al and low pH stresses on planting medium which consisted of (1) pH 4+Al 2 mM, (2) pH 4 without Al, and (3) pH 5.8 without Al (control). The MmCu/Zn-SOD transgene in the genome of the transgenic IPB CP3 plants remained stable. The resistance levels of transgenic clones to Al and low pH varied. The P3SOD3 and P3SOD10 clones had the highest level of resistance to Al and low pH stresses.
Keyword: french fries, genotipe kentang, in vitro, keripik kentang, transgen

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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