Judul: Pendugaan Heritabilitas dan Seleksi Populasi F4 Sorgum (Sorghum bicolor (L.) Moench).
Abstrak: Pendugaan heritabilitas dan seleksi merupakan kegiatan penting dalam keberhasilan pemuliaan tanaman. Percobaan ini dilaksanakan di BB Biogen, Cimanggu, Bogor pada bulan Mei-Agustus 2017. Populasi F4 yang diuji merupakan turunan dari F1 hasil persilangan koleksi ICRISAT dan varietas nasional yaitu (PI-150-20A x Numbu). Hasil penelitian menunjukan bahwa terdapat keragaman genetik pada populasi F4 yang diuji dengan nilai koefisien keragaman genetik antara 11,43%-41,55%. Nilai heritabilitas tinggi ditemukan pada tinggi tanaman. Diameter batang, jumlah daun, panjang dan diameter malai, bobot malai, bobot biji malai-1 menunjukan heritabilitas sedang. Seleksi tanaman dilakukan secara langsung di lapangan dengan memperhatikan tinggi tanaman, diameter batang serta bentuk dan ukuran malai yang menghasilkan delapan belas tanaman terbaik. Tanaman yang terseleksi direkomendasikan untuk tahap-tahap pemuliaan selanjutnya.
Keyword: heritabilitas, keragaman genetik, seleksi

Judul: Pendugaan Ragam Genetik Dan Seleksi Populasi F2 Sorgum (Sorghum Bicolor (L.) Moench) Di Kebun Percobaan Leuwikopo Darmaga
Abstrak: Pendugaan ragam genetik dan seleksi merupakan kegiatan penting dalam keberhasilan kegiatan pemuliaan tanaman. Penelitian ini bertujuan untuk melakukan pendugaan aksi gen, pendugaan keragaman genetik dan melakukan seleksi pada populasi F2 sorgum berdasarkan karakter hasil. Penelitian ini dilaksanakan di Kebun Percobaan Leuwikopo IPB pada bulan Februari 2015 hingga Juli 2015. Populasi F2 terdiri dari PI 10-90-A x Numbu, PI 150-20-A x Numbu, dan PI 150-20-A x Kawali. Seleksi dilakukan dengan intensitas 10%. Semua karakter kualitatif yan diamati dikendalikan oleh dua pasang atau lebih pasangan gen, kecuali eksersi malai pada populasi PI 150-20-A x Kawali yang dikendalikan satu pasang gen. Tipe aksi gen yaitu aditif, dominan penuh, resesif epistasis, semiepistasis, dan epistasis kompleks. Karakter kuantitatif dikendalikan oleh banyak gen dan sedikit gen dengan tipe aksi gen yaitu hanya aditif, epistasis aditif, epistasis duplikat, dan epistasis komplementer. Melalui pendugaan ragam diperoleh karakter-karakter yang memiliki heritabilitas tinggi. Seleksi yang dilakukan berhasil memilih 15 tanaman terbaik dari setiap populasi.
Keyword: aksi gen, heritabilitas, korelasi, nisbah Mendel, seleksi

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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