Judul: The Effect of Colchicine Treatment on Morphological Diversity of Portulaca (Portulaca grandiflora Hook)
Abstrak: Portulaka atau lebih dikenal tanaman krokot adalah salah satu jenis tanaman berbunga cantik yang hidup di daerah tropis yang mudah untuk dibudidayakan karena pertumbuhannya yang terbilang cepat. Salah satu jenisnya, yaitu Portulaca grandiflora Hook atau biasa disebut Sutra Bombay yang merupakan tanaman sekulen dari Amerika Selatan. Mutasi pada portulaka dapat dilakukan dengan berbagai jenis, seperti mutasi kimia ataupun mutasi fisik. Mutasi kimia pada jenis portulaka salah satunya dengan penggunaan mutagen kimia berupa kolcisin. Penelitian ini bertujuan mengetahui pengaruh pemberian kolcisin terhadap morfologi tanaman portulaka (Portulaca grandiflora Hook). Penelitian ini dilaksanakan selama 4 bulan di Kebun Percobaan Leuwikopo IPB menggunakan Rancangan Acak Lengkap (RAL) faktorial. Penelitian menunjukkan adanya perbedaan respon morfologi pada setiap perlakuan konsentrasi dan genotipe yang digunakan. Karakter kuantitatif yang diamati pada perlakuan genotipe Bicolor dengan konsentrasi sebesar 0,15% menunjukkan respon yang paling baik untuk peubah tinggi tanaman dan genotipe Banana dengan konsentrasi 0,2% untuk peubah diameter batang. Pada genotipe Peach dengan konsentrasi 0,15% menunjukkan hasil yang paling baik terhadap peubah jumlah bunga. Selain itu, jumlah cabang yang paling baik pada genotipe Orange dengan konsentrasi 0,05%. Hasil berbeda pada karakter kualitatif yang diamati menunjukkan belum ada perbedaan yang nyata pada peubah bentuk dan warna bunga saat pemberian konsentrasi di setiap genotipenya., Portulaca or better known as krokot is one type of beautiful flowering plan that lives in the tropics which is easy to cultivate because its fairly fast to growth. One type, namely Portulaca grandiflora Hook or commonly called Sutra Bombay is a succulent plant from South America. Mutations in portulaca can be carried out in various type, such as chemical mutations and physical mutations. One of the chemical mutations in the portulaca species is the use of chemical mutagen in the form of colchicine. This research was conducted for 4 months at the Leuwikopo Experimental Garden of IPB using a factorial Completely Randomized Design (CRD). The research showed that there were differences in morphological responses to each concentration and genotype treatment used. The quantitative characters observed in the Bicolor genotype treatment with a concentration of 0.15% showed the best response for the plant height variable and the Banana genotype with a concentration of 0.2% for the stem diameter variable. The Peach genotype with a concentration of 0.15% showed the best results on the number of flowers variable. In addition, the best number of branches on the Orange genotype with a concentration of 0.05%. The different results on the observed qualitative characters showed that there were no significant differences in the shape and color of the flowers when the concentration was given to each genotype.
Keyword: concentration, genotype, mutation

Judul: Content of Total Flavonoids, Phenolics, and Antioxidant Activity of Purslane (Portulaca grandiflora Hook.) Result of the Colchicine Mutation
Abstrak: Kandungan total flavonoid, fenolik dan aktivitas antioksidan pada tanaman krokot (Portulaca grandiflora Hook.) hasil mutasi dengan kolcisin belum diketahui. Penelitian bertujuan mengetahui konsentrasi kolcisin yang menyebabkan peningkatan kandungan total flavonoid dan fenolik yang terbaik sehingga meningkatkan aktivitas antioksidannya pada tanaman krokot. Krokot diekstraksi dengan metode Microwave Assisted Extraction dan pelarut metanol 96%. Kadar total fenolik dihitung dengan metode Folin-Ciocalteu, kadar total flavonoid dengan metode AlCl3, serta aktivitas antioksidan dengan metode DPPH dan FRAP. Kadar total fenolik dan aktivitas antioksidan DPPH tertinggi terdapat pada sampel K2G3 (0,789 ± 0,026 mg GAE g-1 bobot basah dan 0,964 ± 0,011 µmol TE g-1 bobot basah). Kadar total flavonoid dan aktivitas antioksidan FRAP tertinggi terdapat pada sampel K1G3 (0,477 ± 0,030 mg QE g-1 bobot basah dan 5,776 ± 0,279 µmol TE g-1 bobot basah). Pemberian mutagen kolcisin sebesar 0,05% meningkatkan total flavonoid (46%) dan aktivitas antioksidan FRAP krokot (1,13 kali), sedangkan mutagen kolcisin sebesar 0,1% meningkatkan total fenolik (44%) dan aktivitas antioksidan DPPH krokot (3,56 kali).
Keyword: Antioksidan, Fenolik, Flavonoid, Kolcisin, Mutasi

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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