Judul: Induksi Kalus Rumput Laut Gracilaria verrucosa Menggunakan Zat Pengatur Tumbuh Indol Acetic Acid dan Benzyl Amino Purine Secara In Vitro
Abstrak: Gracilaria verrucosa merupakan jenis rumput laut merah (Rhodophyta) penghasil agar (agarophyte) yang bernilai ekonomi tinggi. Kendala yang dihadapi dalam pembudidayaan rumput laut ini yaitu rendahnya ketersediaan bibit, serangan penyakit, serta penurunan kualitas agar. Teknik kultur jaringan embriogenesis somatik dapat dikembangkan untuk perbanyakan rumput laut lebih cepat dan dapat digunakan untuk sarana perbaikan genetik sehingga dapat mengatasi permasalahan tersebut. Tujuan penelitian ini untuk memperoleh metode induksi kalus dengan penambahan zat pengatur tumbuh indol acetic acid (IAA) dan benzyl amino purine (BAP). Pemeliharaan sumber eksplan pada waktu lebih lama (4 minggu) menghasilkan lebih banyak bahan eksplan steril dibandingkan pemeliharaan eksplan pada waktu singkat (2 minggu). Penggunaan zat pengatur tumbuh IAA dan BAP dapat menginduksi terbentuknya kalus terbaik pada media dengan penambahan IAA 2 mg/l dan BAP 1 mg/l, sedangkan untuk pertumbuhan kalus terbaik pada media yang ditambahkan IAA 2 mg/l tanpa BAP dengan terbentuknya kalus hanya menutupi < 20 % perlukaan eksplan talus.
Keyword: Gracilaria verrucosa, induksi kalus, kultur jaringan

Judul: Nutrient enrichment and postharvest culture technology to enhance the quality of Gracilaria verrucosa
Abstrak: Gracilaria verrucosa merupakan rumput laut penghasil agar yang penting di Indonesia. Budidaya salah satu jenis Rhodophyta ini umumnya hanya mengandalkan air yang tersedia yang berada disekitar tambak, sehingga produksi yang tinggi berasal dari perluasan areal budidaya, bukan akibat peningkatan produktivitas rumput laut tersebut. Studi tentang rumput laut menunjukkan bahwa salah satu faktor pendukung meningkatnya produktivitas adalah ketersediaan nutrien yang memadai. Selain peningkatan produktivitas, hal yang harus dipertimbangkan dalam budidaya rumput laut, G. verrucosa adalah kualitas agar yang merupakan hasil ekstraksi dari rumput laut ini. Oleh sebab itu, penelitian ini mencoba untuk mengkaji peningkatan produktivitas melalui pengkayaan nutrien, dan memperbaiki kualitas agar rumput laut, G. verrucosa sejak masa budidaya. Penelitian ini bertujuan untuk mengetahui respon pertumbuhan G. verrucosa yang diberi pengkayaan berbagai nutrien, serta mengkaji efektivitas perlakuan gelap, juga kombinasi perlakuan gelap dan salinitas yang ditingkatkan pada budidaya pascapanen dalam meningkatkan kualitas G. verrucosa., The economic important of Gracilaria verrucosa is undoubted as its being the raw material world-wide in agar production. In Indonesia, cultivation of this species has been employed broadly, however this magnitude growth merely due to expansion of farm area. In general, farmers only rely on available water surround the pond for their culture condition, while previous studies mentioned that one factor to be considered to enhance productivity is the availability of nutrients properly. Besides quantities production of raw materials, it must be consistent with the quality of agar that extracted from Gracilaria verrucosa. This study was aimed to determine the growth response of G. verrucosa following a variety of nutrients enrichment, as well as to assess the quality of G. verrucosa upon he postharvest culture of dark or dark and increased salinity treatments.
Keyword: productivity, postharvest culture, agar content, agar production, gel strength, Gracilaria verrucosa, Postharvest cultivation technology, Food additive

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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