Judul: Pengaruh beberapa auksin dan sitokinin terhadap perkecambahan dan pertumbuhan teratai (Nymphaea lotus L.) secara in vitro
Abstrak: Tujuan dari penelitian ini adalah mempelajari penga- ruh beberapa auksin dan sitokinin terhadap perkecambahan serta pertumbuhan dan perkembangan kecambah Nymphaea lotus L. secara in vitro. Eksplan yang digunakan dalam penelitian adalah biji Nymphaea lotus L. yang diperoleh dari Bank Biji Kebun Raya Bogor yang berdiameter ± 2 mm. Benih yang telah disterili- sasi ditanam dalam media perkecambahan dengan perlakuan IAA (0.1 dan 0.5 mg/l) yang dikombinasikan dengan sitokinin BAP, kinetin, dan thidiazuron (masing-masing dengan dosis 0.1 dan 0.5 mg/l), sehingga diperoleh sejumlah 12 kombinasi perlakuan. Lingkungan perkecambahan diatur dalam keadaan terang 7-10 hari dilanjutkan gelap. Tanaman hasil perkecambahan yang berasal dari media perkecambahan yang mengandung thidiazuron dan telah memi- liki daun minimal 2 buah dipindahkan ke media pertumbuhan selanjutnya, yaitu subkultur I ke media dengan IBA 0.1 ppm (8 minggu). Pada subkultur II terdapat 2 perlakuan. Perla- kuan 1 IBA 1 ppm, kinetin 1 ppm dan glutamin 250 mg/1 (8 minggu); perlakuan 2 NAA 2 ppm dan BAP 2 ppm selama ...
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Judul: Pengaruh auksin NAA, IBA, IAA dan Sitokinin 2-iP terhadap pengakaran Asparagus (Asparagus officinalis L.) secara in Vitro
Abstrak: Penelitian ini bertujuan untuk mempelajari pengaruh tiga jenis auksin yaitu NAA, IBA dan IAA dengan sitokinin 2-iP, terhadap pertumbuhan dan perkembangan jaringan tanaman asparagus khususnya jaringan akar. Penelitian ini merupakan percobaan faktor tunggal dengan enam perlakuan. Sebagai perlakuan adalah tiga jenis auksin NAA, IBA dan IAA, masing-masing dengan dua taraf yaitu 0.25 mg/l dan 0.5 mg/l. Rancangan percobaan yang digunakan adalah rancangan acak lengkap dengan ulangan. 10 Hasil percobaan menunjukkan bahwa pemberian jenis auksin yang berbeda pada medium yang mengandung nin 2-iP menghasilkan arah dan pola pertumbuhan sitoki asparagus yang berbeda. Auksin dari jenis NAA cenderung mendorong eksplan untuk membentuk akar daripada membentuk tunas. Sedangkan auksin dari jenis IAA dan IBA lebih terarah pada pembentukan tunas dan pertambahan tinggi tunas asparagus. Pertambahan tinggi tunas yang cepat didapatkan dari eksplan yang ditanam dalam medium IAA dan IВА, terutama antara minggu kesatu dan minggu keempat. Nilai pertambahan tinggi tunas yang terbesar pada pengamatan minggu ke-14 diperoleh dari perlakuan IAA 0.25 mg/l sedangkan yang terendah pada perlakuan NAA 0.25 mg/l...
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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