Judul: Induksi Pembelahan Sporofitik Mikrospora Kedelai Melalui Kultur Antera Pada Sistem Media Dua Lapis
Abstrak: Pemuliaan kedelai masih dilakukan secara konvensional, yaitu dengan cara menyilangkan antar varietas yang dilanjutkan dengan proses seleksi untuk menghasilkan varietas baru. Proses ini membutuhkan waktu yang lama, khususnya dalam proses seleksi untuk memperoleh galur-galur yang stabil secara genetik, yaitu 7-8 generasi. Untuk itu diperlukan introduksi teknik untuk mempercepat stabilitas genetik dari suatu hasil persilangan. Salah satu alternatif untuk mempercepat stabilitas genetik adalah teknologi haploid melalui induksi androgenesis untuk embriogenesis.
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Judul: Perkembangan Mikrospora dan Induksi Pembelahan Sporofitik pada Kultur Antera Kelapa Sawit (Elaeis guineensis Jacq.)
Abstrak: Pengembangan varietas hibrida kelapa sawit membutuhkan ketersediaan galur-galur murni untuk dijadikan tetua. Teknologi haploid dapat dikembangkan untuk menghasilkan galur-galur murni (tanaman haploid ganda) secara efisien hanya dalam 1-2 generasi. Penelitian ini bertujuan menginduksi pembelahan sporofitik pada kultur antera dalam media dua lapis yang merupakan langkah awal pengembangan kultur haploid pada kelapa sawit. Pangkal spikelet dari spikelet yang terdapat pada pangkal malai dari malai jantan yang memiliki ¼ bagian pangkal malai berwarna kuning dan ¾ bagian ujung malai berwarna coklat mengandung mikrospora tahap uninukleat akhir. Sedangkan ujung spikelet dari spikelet yang terdapat pada ujung malai dari malai jantan berwarna coklat dan sebagian seludang telah terbuka mengandung mikrospora tahap biselular awal. Mikrospora tahap uninukleat akhir yang dikulturkan pada media standar embriogenesis somatik kelapa sawit, memperlihatkan perkembangan gametofitik sampai tahap biselular pada umur 6 sampai 10 hari setelah kultur (HSK). Pemberian cekaman suhu tinggi (32-33ºC) dalam periode 0, 1, 3 dan 7 hari yang dikombinasikan dengan perlakuan sumber karbon berupa sukrosa, maltosa ataupun manitol tidak dapat menginduksi pembelahan sporofitik dalam antera pada kutur in vitro. Namun perlakuan cekaman suhu tinggi selama satu hari yang dikombinasikan dengan sumber karbon maltosa 40 g/l dapat mempertahankan persentase mikrospora hidup sebesar 74.5% sampai 28 HSK.
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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