Judul: Analisis Lintas Beberapa Sifat Agronomi Plasma Nutfah Gandum (Triticum aestivum L.)
Abstrak: Penelitian ini menggunakan data percobaan yang merupakan hasil penelitian Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian (BB- Biogen) Bogor. Percobaan dilaksanakan pada bulan Juni hingga Oktober 2002 di Instalasi Percobaan Pacet, Jawa Barat menggunakan rancangan acak kelompok (RAK) dengan 66 genotipe gandum sebagai perlakuan yang diulang sebanyak tiga kali. Sehingga secara keseluruhan terdapat 198 satuan percobaan. Tujuan dari penelitian ini adalah untuk membandingkan pengaruh varietas dan kelompok terhadap sifat agronomi tanaman gandum dengan analisis ragam peubah ganda dan mengetahui peubah yang berpengaruh secara langsung dan berpengaruh tidak langsung terhadap hasil biji total tanaman gandum serta menentukan besarnya pengaruh tersebut dengan analisis lintas. Analisis ragam peubah ganda (Manova) merupakan teknik analisis statistik yang digunakan untuk menguji tentang perbedaan pengaruh beberapa vektor rata-rata populasi. Hasil Manova menunjukkan bahwa terdapat perbedaan pengaruh antara perlakuan dan kelompok terhadap sifat-sifat agronomi tanaman gandum. Oleh sebab itu, setiap data unit percobaan digunakan dalam analisis lintas. Analisis lintas merupakan metode untuk mengkaji pengaruh langsung dan tidak langsung dari peubah-peubah penyebab terhadap peubah-peubah lain sebagai peubah akibat. Hasil analisis lintas plasma nutfah gandum yang dikelola BB-Biogen terhadap peubah hasil biji/plot diperoleh kesimpulan bahwa peubah umur masak, umur berbunga, laju pengisian biji dan waktu pengisian biji memberikan pengaruh langsung yang terbesar terhadap penambahan hasil biji/plot. Pengaruh tidak langsung terbesar diberikan oleh peubah rasio organ produktif terhadap tinggi tanaman melalui peubah rasio panjang tangkai malai terhadap jumlah biji/ malai. Pengaruh total terbesar terhadap hasil biji/plot diberikan oleh peubah rasio anakan produktif melalui jumlah anakan produktif. Hal ini menunjukkan bahwa sifat agronomi yang paling berpengaruh terhadap hasil biji yaitu banyaknya jumlah anakan yang dihasilkan dari organ produktif. Varietas yang baik dikembangkan melalui beberapa peubah tersebut adalah V-196, V-182, V-234, V-170 dan V-132. Oleh karena itu peubah-peubah dan varietas-varietas tersebut perlu diperhatikan pada saat melakukan seleksi terhadap plasma nutfah gandum, terutama untuk mengoptimalkan hasil biji.
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Judul: Keragaman Genetik, Heritabilitas, Dan Analisis Koefisien Lintasan Pada Plasma Nutfah Gandum (Triticum Aestivum L.) Koleksi Balitbiogen
Abstrak: The aims of this experiment are to study the geneUc variation, heritability of the wlleat germplesm collection and cotrelation among chafllctelS using pathcoefficient analysis. This experiment was conducted at Rice Research Station in Kuningan, West Java on June until October 2002 using RandOmized Completely Block Design (RCBD) with three replications. each of the twenty-seven genotypes of wheat was planted on four rows with 3 m lenght. The interrow and interplant spacing were 25 em and 10 em, respectivity. Deta obtained from the twenty-seven genotypes were subjected to variance analysis and the heritability of the traits _mated by component of variance method. Correlation coefflcients were computed according to the formula of Goulden (1959). Direct and indirect path coefflcients were calculated as described by Dewey and Lu (1959). High geneUc varianon displayed by l00-grain weight, numberofUllelS per plant and number of spikes per plant The esUmation of heritability ranged from 0 to 94.58%. The days to nower, plant height, spike length, number of greins per spike, and l00-grain weight were uncotrelated with grain yield per plant. In the other hand, the days to harvest, number of tillelS per plant, number of Spikes per plant, dry spikes weight, and harvest spikes weight were positively and significanty correlated with grain yield per plant. The number of graints per plant, number of spikes per plant, number of grains per spike, and l00-grein weight each had a posiwe direct effect on grain yield per plant. The indireci effect on grain yield per plant via number of tillers and number of Spikes (productive tillers ) per plant showed by days to harvest, dry Spikes weight, and harvest Spikes weight. The number of productive tillers per plant was a good criteria to be used towards improvement of grain yield.
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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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