Judul: Interaksi Antara Sreptomyces .p. Dengan Bacillus subtilis, xanthomonas campesltis pv glycine, rhizobia Dan Pseudomonas sp. MK I
Abstrak: K.edeIai merupakan tanaman penanian yang penting di Indonesia. Pertumbuhan tanaman kedelai dapat ditingkatkan oleh kehadiran bakteri. binti1 akar dan bakteri pelarut fosfat. Salah satu kendala dalam meningkatkan produksi kedelai adalah penyakit kedelai yang disebabkan oleh bakteri patogen seperti Xanthomonas campestris pv glycine (pusbJl kedelai) dan Bacillus subtilis (busuk benib). Streptomyces sp.merupakan bakteri tanah yang banyak digunakan sebagai"agen biokontrol karena kemampuannya menghasilkan senyawa antibakteri. PeneIitian ini bertujuan untuk menapis Streptomyces sp. yang efektif menghambat pertumbuhanXanlhomonas campestris pv glycine dan Bacillus subtills patogen kedelai serta mengkaji penghambatan Streptomyces sp. terhadap bakteri bintil akar dan bakleri pelarut P. Luaran dari penelitian ini diharapkan dapat menjadi infonnasi dasar dalam pembuatan produk biologi yang berperan ganda sebagai pupuk: hayati dan biokontrol. Uji antagonis isolat Streptomyces sp. terhadap bakterl target menggunakan metode difusi agar (agar difusion methode) (Madigan et a/1997) dan diameter zona hambatan diukur berdasarkan kepada Suriawiria (1973). Aktifitas filtrat kultur terhadap bakteri target diqji dengan menggunakan metode Kilby Bauer (Madigan et aJ 1997) dengan tehnik cawan "cakmn kertas"(paper disk plate). Begitujuga dengan uji stabilitas aktivitas filtrat kultur terhadap pH dan suoo menggtmakan metode yang sama. Dari 61 isolat Streptomyces sp. koleksi Laboratorium Bioteknologi Kehutanan Pusat Penelitian Bioteknologi IPB dan Laboratorium Mikrobiologi FMIP A IPB diperoleh 10 kelompok wama koloni isolat Streptomyces sp. yang beIbeda yaitu coklat muda, ooIdal, putih, abu-abu, jingga, orange, merah mnda, hitam, hijau dan kwring. Sebanyak 7 isolat yaitu PS 1-4, LC 2-1, IVF 1-2, PS 4- 12, U 22-2, SB 8-12 dan SB 8-18. mampu
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Judul: Penapisan Streptomyces spp. penghasil senyawa penghambat pertumbuhan Phakopsora pachyrizi secara in vitro dan in planta
Abstrak: Phakopsora pachyrizi merup akan patogen obligat pada tanaman kedelai yang menyebabkan penyakit karat. Penyakit ini dapat mengakibatkan kerontokan daun, penurunan mutu benih dan produktivitas kedelai. Informasi mengenai upaya pengendalian P. pachyrizi secara hayati masih belum banyak dilaporkan. Streptomyces merupakan salah satu bakteri tanah yang potensial sebagai agen pengendali hayati P. pachyrizi. Penelitian ini bertujuan menapis Streptomyces spp. yang bersinergi dengan bakteri penambat N dan bakteri pelarut P serta mampu menghambat pertumbuhan P. pachyrizi yang menyerang tanaman kedelai secara in vitro dan in planta. Dua belas isolat Streptomyces spp. digunakan dalam penelitian ini. Tiga varietas kedelai yang memiliki sifat ketahanan berbeda terhadap P. pachyrizi digunakan dalam uji in planta. Filtrat KS- 1 memiliki aktivitas penghambatan perkecambahan uredospora terbesar (90.5%). Hal ini mengindikasikan adanya aktivitas antifungi di dalam filtrat tersebut. Interaksi sinergis antara bakteri penambat N dan bakteri pelarut P serta filtrat KS-1 dapat meningkatkan jumlah bintil, berat kering bintil dan kandungan N total tanaman. Intensitas serangan mengalami penurunan akibat pemberian KS-1 pada varietas Tanggamus (56.15%), Wilis (26.21%), dan Nokhonsawon (21.47%). Penurunan intensitas penyakit karat oleh filtrat KS-1 dapat meningkatkan berat kering total (39.6%), berat kering biji (97.8%), dan jumlah biji (50%) pada varietas Tanggamus. Sedangkan pada varietas Nokhonsawon pemberian KS-1 dapat meningkatkan jumlah biji (34.5%). Namun demikian, pada varietas Wilis pemberian KS-1 tidak secara nyata mempengaruhi berat kering total, berat kering biji, dan jumlah biji. Selain memiliki aktivitas antifungi, filtrat KS-1 diduga juga memiliki aktivitas senyawa pemacu tumbuh.
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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