Judul: Manipulasi asam amino dan bentuk fisik medium terhadap embriogenesis somatik kentang (Solanum tuberosum L.)
Abstrak: Tujuan percobaan untuk mengetahui sumber N reduksi, perbandingan sumber N reduksi dengan No3- dan konsentrasi N terhadap produksi kalus dan embrio somatik serta perbedaan respon dari dua bentuk fisik medium. Percobaan ini meliputi tiga percobaan utama, ketiganya menggunakan rancangan perlakuan faktorial dalam acak lengkap dengan empat ulangan untuk percobaan seri I dan II serta tujuh ulangan untuk percobaan seri III. Seluruh faktor perlakuan dicobakan pada dua kultivar kentang yaitu Red Pontiac dan Katahdin. Percobaan seri I perlakuannya terdiri dari tiga faktor yaitu jenis sumber N reduksi (glutamat dan NH4 +), perbandingan sumber N reduksi dengan NOJ- (1:2, 1:3, 1:4 dan 1 :6) serta konsentrasi N (15 mM dan 30 mM). Percobaan seri II terdiri dari empat faktor yaitu jenis dan konsentrasi auksin (2,4-D dan 4-CPA masing-masing 0.5; LO; 2.0; 4.0 mg/1) sertajenis dan konsentrasi sitokinin (Kinetin dan BAP masing-masing 0.0; 0.5; 1.0; 2.5; 5.0 mg/I). Percobaan seri III perlakuannya terdiri dari jenis sumber N reduksi (glutamat, aspartat, glutamin dan asparagin), perbandingan surnber N reduksi dengan N03- (l :4 dan 1:5) dan konsentrasi N (15 mM dan 30 mM). Pengamatan meliputi persentase warna kalus, persentase ku alitas kalus, produksi kalus, bobot kering kalus, pengamatan jaringan, analisis asam amino, N03- dan NH4 + pada medium kultur. ...
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Judul: Pengaruh asam amino alanin, glisin, dan glutamin serta bentuk fisik medium terhadap embriogenesis somatik kentang (Solanum tuberosum L.)
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh berbagai jenis nitrogen reduksi (NH4, alanin, glisin, dan glutamin), jumlah nitrogen (15 mM dan 30 mM), dan nisbah N reduksi dengan N oksidasi (1:4 dan 1:5) terhadap produksi kalus dan embriosomatik kentang. Penelitian ini diawali dengan percobaan pendahuluan (yang dilakukan bersama rekan peneliti lain), dan dipero- leh kombinasi 2,4-D dan 4-CPA serta nisbah N red. N oks. 1:4 dan 1:5. Hasil tersebut selanjutnya digunakan dalam percobaan embriogenesis. Percobaan embriogenesis terdiri atas 4 seri perco- baan berdasarkan 2 kultivar kentang (Red Pontiac dan Katahdin) dan cair). 2 bentuk fisik medium (padat dan padat- Bahan tanaman diambil dari umbi mini hasil perban- yakan stek mikro di lapang sebagai eksplan. Medium dasar yang digunakan adalah MS dengan pemberian jenis, jumlah dan nisbah nitrogen sesuai dengan perlakuan. Setiap perlakuan dalam percobaan ini diulang 5 kali. Penelitian dilakukan sebanyak 3. tahap percobaan, masing-masing tahap terdiri atas 4 seri. Tahap kalus, Ia dan yang merupakan induksi kalus, tahap Ib regenerasi tahap II adalah induksi embriogenesis. Medium pada tahap Ia berupa MS yang ditambahkan zat pengatur tumbuh 2,4-D sebanyak 4 mg/l dikombinasikan dengan kinetin sebanyak 0.5 mg/1 (konsentrasi ini berdasarkan percobaan pendahuluan), serta arang aktif sebanyak 0.2 %. Medium tahap Ib mengandung zat pengatur tumbuh tanpa arang aktif, masih sedang- kan tahap II tanpa zat pengatur tumbuh maupun arang aktif. Pengamatan dilakukan terhadap produksi dan kualitas kalus yang dihasilkan, baik pada tahap Ia, Ib, maupun II. Di samping itu dilakukan pula pengukuran kandungan nitro- gen pada medium dan juga uji histologis terhadap jaringan kalus yang terbentuk.
Keyword: Solanum tuberosum L.

Judul: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite