Judul: Daya Regenerasi Cendawan Mikoriza Arbuskula Gigaspora sp. Asal Kultur Aksenik
Abstrak: Kultur aksenik cendawan mikoriza arbuskula (MA) merupakan cara untuk mengisolasi, menumbuhkan, dan mempelajari proses biologi dari cendawan MA dalam kondisi aseptik. Penelitian ini bertujuan untuk mempelajari daya regenerasi cendawan MA Gigmpora sp. asal kultur aksenik. Inang yang digunakan ialah kultur akar wortel yang ditumbuhkan pada media White selama 20 hari sebelum diinokulasi. Inokulum cendawan MA yang digunakan ialah spora, hifa eksternal, scrta akar terkolonisasi Gigawora sp. asal kultur akscnik yang berumur lima bulan. Pertumbuhan inokulum dan daya kolonisasinya pada akar diamati setiap hari selama 10 minggu dengan menggunakan mikroskop.
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Judul: Isolasi dan Identifikasi Cendawan Mikoriza Arbuskula  Asal Tanah Pertanian dan Perkebunan Jawa Barat
Abstrak: Cendawan Mikoriza Arbuskula (CMA) ialah cendawan tanah yang bersimbiosis mutualistik dengan akar tumbuhan yaitu sekitar 80% tumbuhan berpembuluh. CMA memiliki keragaman yang cukup tinggi dan berperan dalam mempertahankan keragaman tumbuhan dan pemeliharaan ekosistem, namun penelitian di Indonesia tentang keanekaragaman CMA masih terbatas. Oleh karena itu penelitian ini bertujuan untuk mengidentifikasi CMA asal tanah pertanian dan perkebunan di Jawa Barat, berdasarkan karakter morfologi spora. Contoh tanah berasal dari rizosfer Oryza sativa L. dari Majalengka (D1) dan Cianjur (D4), Arachis hypogaea L. dari Majalengka (D2 dan D9), Zea mays L. dari Majalengka (D3, D6 dan D8), Ipomoeae batatas L. dari Majalengka (D7), Hevea brasiliensis Mull. Arg. dari Bogor (D11) dan tanah pertanian dari Majalengka (D5 dan D10). Contoh tanah dan zeolit steril dibuat biakan pot untuk perbanyakan spora CMA dengan menggunakan Sorghum bicolor Benth. dan Centrosema pubescens Benth. sebagai tanaman inang. Spora diisolasi dari biakan pot dengan menggunakan metode tuang saring basah dilanjutkan dengan sentrifugasi. Spora CMA yang berhasil diisolasi dan diidentifikasi tergolong ke dalam dua genus yaitu Acaulospora dan Glomus. Anggota Acaulospora yang berhasil diidentifikasi terdiri atas A. delicata (D1), A. foveata (D7), dan A. tuberculata (D9) sedangkan Glomus terdiri atas G. diaphanum (D6), G. etunicatum (D3, D4, D5, D6, D8, D9 dan D11),G. geosporum (D1, D3, D6 dan D10), G. intraradices (D1 dan D2) dan Glomus sp.1 (D2, D5 dan D10).
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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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