Judul: Seed-Borne Pathogens and the Effects of Sorting and Electrotherapy on Soybean Viability
Abstrak: Kedelai merupakan komoditas pangan penting di Indonesia. Produksi kedelai cenderung menurun dari tahun 2017 hingga 2022. Produksi kedelai nasional belum mampu mencukupi kebutuhan dalam negeri sehingga pemerintah mengimpor kedelai sekitar 2,48 juta ton pada tahun 2021. Patogen terbawa benih menjadi penting karena merugikan secara kualitas dan kuantitas produksi tanaman kedelai. Penelitian ini bertujuan untuk mengidentifikasi bakteri dan cendawan terbawa benih kedelai dan mengetahui pengaruh elektroterapi terhadap viabilitas benih hasil sortasi. Metode meliputi isolasi dan identifikasi bakteri dan cendawan terbawa benih dengan metode pengenceran dan blotter test, pengujian Gram, uji reaksi hipersensitivitas, dan perlakuan elektroterapi untuk benih yang dibedakan dalam benih tanpa gejala, bergejala dan acak hasil sortasi. Isolat bakteri terbawa benih kedelai berdasarkan karakter morfologi dan fisiologinya teridentifikasi sebagai Xanthomonas sp., Pseudomonas sp., dan Ralstonia solanacearum. Sedangkan isolat cendawan teridentifikasi sebagai Aspergillus flavus, A. niger, Trichoderma sp., Sclerotium rolfsii, dan Penicillium sp.. Elektroterapi terhadap benih kedelai dilakukan dengan tegangan 12 V DC dan arus 1 A pada konsentrasi NaCl 1 M dalam waktu 0, 5, 10, 15, dan 20 menit pada masing-masing sortasi benih memberikan pengaruh negatif viabilitas benih dan panjang tajuk tanaman. Dua penyakit ditemukan pada tanaman selama 11 MST dari benih kedelai hasil elektroterapi, yaitu bercak daun (Curvularia sp.), dan penyakit mosaik yang diduga Soybean mosaic virus, Soybean is an important food commodity in Indonesia. Soybean production has tended to decline from 2017 to 2022, unable to meet national demand. As a consequence, the government imported around 2.48 million tons of soybeans in 2021. Pathogens carried by seeds are important because they harm the quality and quantity of soybean production. This research aims to identify bacteria and fungi carried by soybean seeds and to determine the effect of electrotherapy on the viability of sorted seeds. The methods include isolating and identifying bacteria and fungi carried by seeds using dilution and blotter test, Gram testing, hypersensitivity reaction testing, and seed electrotherapy distinguished in symptomless, symptomatic, and randomly sorted seeds. Isolates of bacteria carried by soybean seeds based on morphological and physiological characteristics were identified as Xanthomonas sp., Pseudomonas sp., and Ralstonia solanacearum. The identified fungi are Aspergillus flavus, A. niger, Trichoderma sp., Sclerotium rolfsii, and Penicillium sp. Electrotherapy on soybean seeds was conducted at 12 V DC and 1 A with 1 M NaCl concentration for 0, 5, 10, 15, and 20 minutes on each seed sorting showed negative effect on seed viability and plant shoot length. Two diseases were found in plants during the planting period over 11 weeks after planting are leaf spot (Curvularia sp.) and disease suspected to be caused by Soybean mosaic virus.
Keyword: kedelai, elektroterapi, patogen, Bacteria, electric current, fungi, physical/mechanical treatment, soybean production., Bacteria, electric current, fungi, physical/mechanical treatment, soybean production

Judul: Sortation and Electrotherapy of Rice Seed Variety Inpari 42 that Detected to Contain Grain Rot and Leaf Blight Bacterial Pathogen
Abstrak: Burkholderia glumae penyebab penyakit busuk bulir bakteri dan Xanthomonas oryzae pv. oryzae penyebab penyakit hawar daun bakteri merupakan patogen terbawa benih penting pada padi. Upaya pengendalian secara mekanik dan fisik pada benih merupakan alternatif yang perlu dikaji. Penelitian ini bertujuan mengetahui pengaruh sortasi sebagai perlakuan mekanik dan elektroterapi sebagai perlakuan fisik pada benih padi varietas Inpari 42 yang diperoleh dari lot benih lapangan terhadap viabilitas benih. Penelitian ini meliputi pengamatan penyakit dan pengambilan sampel benih padi di suatu lahan sawah milik petani di Kabupaten Bogor. Pengujian kesehatan benih, isolasi dan identifikasi bakteri serta perlakuan sortasi dan elektroterapi dilaksanakan di Laboratorium Bakteriologi Tumbuhan, Departemen Proteksi Tanaman, Fakultas Pertanian, Institut Pertanian Bogor. Berdasarkan karakterisasi morfologi dan uji biokimia, fisiologi, serta reaksi hipersensitivitas, bakteri yang diisolasi dari benih teridentifikasi sebagai B. glumae dan X. oryzae pv. oryzae. Berbagai waktu elektroterapi yang diaplikasikan pada benih yang disortasi menunjukkan hasil yang berbeda nyata pada beberapa peubah respon dan menunjukkan hasil yang lebih baik daripada kontrol pada hampir semua peubah respon. Sortasi benih memberikan perbaikan potensi hasil pada viabilitas benih. Benih tanpa sortasi dan sortasi benih tidak bergejala memberikan hasil yang lebih baik daripada benih gejala. Perlakuan sortasi benih dan elektroterapi tidak berpengaruh terhadap jumlah tanaman yang tumbuh. Namun, perlakuan elektroterapi dengan arus listrik 12 V, 1 A dalam larutan elektrolit NaCl 0,5 M pada durasi berbeda dan sortasi benih memberikan pengaruh yang lebih baik terhadap panjang tajuk selama 5 MST., Burkholderia glumae and Xanthomonas oryzae pv. oryzae which causes bacterial grain rot and leaf blight of rice, respectively, are important seed-borne pathogen in rice. Mechanical and physical control attempts on seeds are an alternative that needs to be studied. This study aims to find out the effects of sortation as mechanical treatment and electrotherapy as physical treatment on Inpari 42 rice seeds obtained from field seed lot on seed viability. The study included the observation of diseases and sampling of rice seeds in a field in the Bogor district. Seed health tests, isolation and identification of bacteria, sorting and electrotherapy treatments were carried out at the Laboratory of Plant Bacteriology, Department of Plant Protection, Faculty of Agriculture, Bogor Agricultural University. Based on morphological characterization and biochemical, physiological, and hypersensitivity tests, the obtained bacteria were indicated as B. glumae and X. oryzae pv. oryzae. The amount of time of electrotherapy applied to sorted seeds showed difference result on some response variables and showed better responses than controls on almost all response variables. Seed sorting provides potential improvements in seed viability. Seeds without sortation and symptomless seeds sub-lot sample showed better results than symptomatic seeds. Sortation of seed and electrotherapy treatments applying electric currents with 12 V, 1 A in 0,5 M NaCl electrolyte at different amount of time gave no significant effect on the number of growing crops. However, electrotherapy gave a better effect on shoot length for five weeks after planting.
Keyword: Arus listrik, Burkholderia glumae, patogen terbawa benih, viabilitas benih, Xanthomonas oryzae pv. oryzae, electric current, seed-borne pathogen, seed viability

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology