Judul: . The Potency of Piperaceae-Originated Yeasts as Agents Biocontrol  Phytophthora capsici, Caused by Basal Stem Rot in Black Pepper
Abstrak: The Potency of Piperaceae-Originated Yeasts as Agents Biocontrol Phytophthora capsici, Caused by Basal Stem Rot in Black Pepper. Biological control is an act of reducing the amount of inoculum or a pathogen's ability to cause disease by one or more organisms. The control mechanism is a strategy used to fight disease-causing pathogens. Based on the detached leaves test, ten epiphytic and endophytic yeast isolates had control levels of P. capsici above 40 to 90%. The aim this study was to determine the antagonism mechanism of yeast isolates, which have antagonistic potential against P. capsici. Yeast epiphytic and endophytic isolates from the Piperaceae famili were tested on PDA media to determine the antibiotic properties, the ability to produce volatile compounds, and hyperparasitism in vitro. Meanwhile, the in vivo test was carried out by inoculating epiphytic and endophytic yeast suspensions on black pepper seeds and continued with suspension inoculation—zoospores of P. capsici in black pepper plants 14 days after inoculation of epiphytic and endophytic yeasts. Based on the selection results obtained, four antagonistic yeast isolates that have the potential to produce antibiotic properties, namely END6, EPT62, EPT63, and END66. Ten epiphytic and endophytic yeast isolates can produce volatile compounds, namely END6, END14, END21, EPT23, EPT62, EPT63, END66, EPT69, EPT70, and END87. Meanwhile, the ability of epiphytic and endophytic yeasts which have hyperparasitic properties was shown by nine isolates, i.e. END6, END14, END21, EPT23, EPT62, EPT63, EPT69, EPT70, and END87. Three of khamir isolates can produce ꞵ-1.3 glucanase enzymes, namely END6, EPT62, and END87. Based on all parameters of in vitro and in vivo assesments, there were three yeast isolates with best characters, i.e. EPT70 and END87 (Hannaella oryzae), and EPT62 (Filobasidium globisporum)
Keyword: antagonism, endophytic, epiphytic, molecular identification, resistance induction

Judul: The Potency of Endophytic Bacteria to Enhance The Resistance of Black Pepper (Piper nigrum L.) againts Phytophthora capsici Leon, the Causal Agent of  Basal Stem Rot Disease (BSR).
Abstrak: Penyakit Busuk Pangkal Batang (BPB) yang disebabkan oleh cendawan P. capsici merupakan penyakit paling penting pada tanaman lada. Penyakit tersebut sudah menyebar di berbagai daerah penanaman lada di Indonesia. Kerugian hasil yang ditimbulkan oleh adanya penyakit BPB pada tanaman lada dapat mencapai 40% setiap tahun. Sampai saat ini belum ada cara efektif untuk mengendalikan penyakit BPB. Indonesia memiliki keanekaragaman mikroba yang sangat tinggi dan banyak diantaranya berpotensi sebagai agens pengendali hayati salah satunya adalah kelompok bakteri endofit. Penelitian ini bertujuan untuk mengeksplorasi dan mengidentifikasi bakteri endofit dari beberapa varietas tanaman lada yang mampu menekan perkembangan penyakit BPB serta menguji daya penekanan bakteri endofit terhadap penyakit BPB secara in vitro dan in vivo pada bibit tanaman lada. Eksplorasi bakteri endofit diisolasi dari tanaman lada yang diambil dari tiga jenis varietas yaitu varietas Natar, Petaling, dan Jambi. Isolat cendawan P. capsici yang digunakan dalam penelitian ini berasal dari koleksi Laboratorium Balai Penelitian Tanaman Obat dan Aromatik Bogor. Isolat yang diperoleh diseleksi potensi antagonismenya terhadap cendawan P. capsici dengan metode biakan ganda pada media PDA. Bakteri endofit terpilih dibiakkan pada media cair Luria Berthani (LB) kemudian diinkubasi bergoyang dengan kecepatan 150 rpm pada suhu ruang selama 72 jam. Perlakuan yang digunakan pada pengujian ini meliputi: aplikasi bakteri endofit secara tunggal, kombinasi antar isolat, aplikasi fungisida, dan kontrol tanpa aplikasi bakteri dan fungisida dengan 4 ulangan dan 5 sub unit bibit tanaman lada pada setiap ulangan. Pengamatan dilakukan terhadap masa inkubasi, kejadian penyakit, penekanan penyakit, keparahan penyakit, dan perkembangan penyakit. Isolat bakteri endofit terpilih diidentifikasi secara molekuler berdasarkan gen 16S rRNA. Ekstraksi DNA bakteri dilakukan menggunakan kit GeneadTM. Amplikasi gen 16 rRNA menggunakan primer universal 27(F5’-AGAG TT TGATCCTGGCTCAG-3’) dan 1492R (5’-GGTTACCTTGTT ACGA CTT-3’). Isolat bakteri terpilih dilakukan karakterisasi secara morfologi bakteri endofit, uji Gram menggunakan KOH 3%, penambat nitrogen, dan reaksi hipersensitif pada tanaman tembakau., Phytophthora capsici as causal agent of basal stem rot (BSR) disease on pepper plants (Piper nigrum L) is a major pathogen of this plant. The objective of this research was to get some endophytic bacteria were able to suppress the growth of Phytophthora capsici by two methods: (1) explored and identified endophytic bacteria from several varieties of pepper plants were able to suppress the progression of the disease, (2) endophytic bacterial antagonism were tested toward Phytophthora capsici by in vitro and in vivo. The results showed that 134 endophytic bacteria from leaves and roots of black pepper have been successfully isolated and produced three isolates selected. The three endophytic bacteria were DJ4, AN21, and DJ8. The incubation period of endophytic bacteria treatment was longer than control treatment, 12-15 days after inoculation (dai) and 10 dai, respectively. The application of endophytic bacteria in suppressing disease progression ranged 51.95% to 95.63% in black pepper seed. Severity of illness ranged from 0%-29.35%. Molecular characterization based on the sequence partial of 16S rRNA showed that three isolates of endophytic bacteria (DJ4, AN21, and DJ8) identified as Agrococcus jenensis, Delfitia tsuruhatensis, and Bacillus licheniformis, three endophytic bacteria were not phytopathogenic.
Keyword: Black pepper, Endophytic bacteria, Phytophthora capsici, Sequencing

Judul: Formulasi Hamiltonian untuk Menggambarkan Gerak Gelombang Soliter Dimensi Tiga di Permukaan Laut
Abstrak: Gelombang permukaan adalah gelombang yang terjadi perbedaan rapat massa antara air dan udara. Salah satu gelombang permukaan yang ditinjau adalah gelombang soliter. Formulasi gelombang soliter dilakukan dengan menggunakan formulasi Hamiltonian.
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