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: Perakitan Tanaman Kentang Kultivar IPB CP1 Transgenik yang Mengandung Gen Penyandi Superoksida Dismutase
Abstrak: Kentang merupakan tanaman hortikultura yang penting di Indonesia. Kentang berperan dalam menjaga ketahanan pangan dengan nilai ekonomi dan kandungan nilai gizi yang tinggi. Kentang dapat dimanfaatkan untuk berbagai olahan seperti kentang sayur, kentang industri seperti keripik kentang dan french fries. Kentang merupakan tanaman yang dibudidayakan di area dataran tinggi. Konversi areal bekas perkebunan teh menjadi perkebunan kentang tidak mudah, karena banyak kendala yang dihadapi petani. Cekaman abiotik seperti pH rendah, aluminium tinggi dan kekeringan menjadi masalah utama yang dihadapi petani kentang. Cekaman abiotik pada tanaman kentang dapat mengarah kepada pembentukan Reactive Oxygen Species (ROS). ROS merupakan produk hasil metabolisme aerob saat menghadapi cekaman, sehingga berbahaya bagi tanaman. Superoksida dismutase (SOD) merupakan salah satu enzim yang berperan untuk mengkatalisasi ROS sehingga tidak berbahaya bagi tanaman. Kentang kultivar IPB CP1 merupakan salah satu bahan baku untuk industri pembuatan keripik kentang. Kentang IPB CP1 tidak begitu toleran terhadap cekaman abiotik. Oleh karena itu, penelitian ini dilakukan untuk mengitroduksikan gen SOD kedalam kentang kultivar IPB CP1 agar kentang menjadi toleran terhadap berbagai cekaman abiotik. Transformasi genetik tanaman kentang dilakukan dengan metode kokultivasi menggunakan bakteri Agrobacterium tumefaciens yang membawa plasmid pGWB5-MmCuZn-SOD. Ruas batang tanpa mata tunas digunakan sebagai eksplan untuk transformasi. Nilai efisiensi transformasi dan regenerasi kentang kultivar IPB CP1 adalah 51,25% dan 38,87%. Analisis integritas dengan menggunakan primer act-F dan act-R menunjukkan semua tanaman transgenik memiliki kualitas DNA yang baik. Analisis integrasi dengan menggunakan primer 35S-F dan SODR2 menunjukkan bahwa delapan tanaman transgenik membawa gen SOD dibawah promotor kuat 35S dengan ukuran pita 633 pb. Analisis uji in vitro cekaman kekeringan, aluminium dan salinitas menunjukkan bahwa tanaman CP1 transgenik lebih toleran dibandingkan dengan tanaman CP1 non transgenik yang ditandai dengan panjang akar total dan jumlah akar yang lebih tinggi., Potato is an important horticultural crop in Indonesia. Potato plays a role in maintaining food security with high economic and nutritional values. Potatoes are used for various preparations such as vegetable, potato chips and french fries. Potato cultivation requires highland environment for optimal growth and production, where in several highland areas there are many non-productive tea plantation that can be used to grow potato. Conversion of tea plantations into potato plantations, however, may face several abiotic stresses such as low pH, higher aluminum, and drought. Abiotic stress usually causes harmful effect to plants, including potato. Superoxide dismutase (SOD) is an enzyme that plays a role in alleviating ROS and replace it into non harmfull molecules. Potato cultivar IPB CP1 is one of the raw materials for the potato chip in food industry, unfortunately IPB CP1 potato is rather sensitive to abiotic stress. Therefore, the research aimed to develop CP1 potato that is tolerant to drought, aluminum, and salinity stresses by introducing MmCuZn-SOD gene mediated by Agrobacterium tumefaciens. The genetic transformation of potato plants was carried out by cocultivation method using Agrobacterium tumefaciens carrying the plasmid pGWB5-MmCuZn-SOD. Stems without buds were used as explants for genetic transformation. The results show the value of transformation efficiency and regeneration of potato cultivar IPB CP1 was 51,25% and 38,87%, respectively. DNA integrity analysis using act-F and act-R primers showed that all
Keyword: cekaman abiotik, gen MmCuZn-SOD, kentang kultivar IPB CP1, tanaman transgenik

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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