Judul: Isolation of Trichoderma from chili farming and its potential in degrading carbendazim fungicides
Abstrak: Cabai merupakan salah satu komoditas hortikultura penting di Indonesia yang dibutuhkan dalam kehidupan sehari-hari dan memiliki nilai ekonomis tinggi. Kebutuhan terhadap cabai terus meningkat sejalan dengan meningkatnya jumlah penduduk dan industri yang membutuhkan bahan baku cabai, namun produksi cabai tidak stabil dan dapat mengalami penurunan. Pada budidaya cabai terdapat beberapa faktor yang dapat menurunkan hasil produksi, salah satunya adalah adanya serangan hama dan penyakit tanaman. Para petani menanggulangi permasalahan hama dan penyakit tanaman tersebut dengan menggunakan pestisida kimia, salah satunya adalah karbendazim. Karbendazim (metil 2-benzimidazol karbamat) adalah fungisida berspektrum luas yang bekerja secara sistemik untuk mengendalikan berbagai macam cendawan patogen pada tanaman. Keberadaan karbendazim dalam tanah dapat mempengaruhi populasi mikroorganisme dalam tanah dan menjadi salah satu cemaran fungisida yang terdeteksi dalam makanan, tanah, dan air. Karbendazim memiliki persistensi lingkungan jangka panjang, oleh karena itu diperlukan mikroorganisme yang kompeten dan kompetitif secara ekologis untuk bioremediasi tanah dan reservoir air yang terkontaminasi, yaitu Trichoderma. Beberapa spesies Trichoderma memiliki enzim yang dapat mendegradasi xenobiotik dalam tanah. Penelitian ini bertujuan untuk menyeleksi, mengisolasi dan mengkarakterisasi spesies Trichoderma yang tumbuh pada tanah yang terpapar fungisida dan berpotensi mampu mendegradasi fungisida berbahan aktif karbendazim. Sepuluh isolat Trichoderma diisolasi dari dua lokasi perkebunan cabai yang diberi perlakuan fungisida berbasis karbendazim secara teratur, dengan kadar residu karbendazim dalam tanah 0,110 ̶ 0,119 ppm. Berdasarkan Analisis filogenetik menggunakan marka ITS, tujuh isolat (S1T1, S1T5, S2T1, S2T2, S2T3, S2T4, dan S2T5) sebagai T. asperellum, sedangkan tiga isolat (S1T2, S1T3, dan S1T4) diidentifikasi sebagai T. hamatum. Trichoderma asperellum S1T1 dan S2T3 menunjukkan toleransi terhadap karbendazim hingga 20 ppm dengan laju pertumbuhan diameter maksimum masing-masing 0,22 cm/hari dan 0,20 cm/hari. Penambahan kedua strain pada tanah dengan yang dikontaminasi 0,05 ̶ 1 ppm karbendazim, meningkatkan degradasi karbendazim sebesar 3% ̶ 11 % ., Chili is one of important horticultural commodities in Indonesia, which is needed in daily life and has high economic value. The need for chilies continues to increase in line with the increasing population and industries that need chili raw materials, but chili production is unstable and can experience a decline. In chili cultivation there are several factors that may reduce production, one of which is the presence of pests and plant diseases. The farmers tackle the problem of pests and plant diseases with chemical pesticides, one of which is carbendazim. Carbendazim (methyl 2-benzimidazol carbamate) is a broad-spectrum fungicide that works systemically to control various kinds of pathogenic fungi in plants. The presence of carbendazim in the soil can affect the microbiome in the soil and be recognized as contaminants in food, soil and water. Carbendazim has long-term environmental persistence, therefore a competent and ecologically competitive microorganism is needed for bioremediation of contaminated soil and water reservoirs, namely Trichoderma. Some Trichoderma species have enzymes that can degrade xenobiotics in soil. This study aims to screen, isolate and characterize Trichoderma species that have the potential to thrive in soil exposed to fungicides and are capable of degrading the fungicide carbendazim. Ten Trichoderma isolates were obtained from two chili plantation locations regularly treated with carbendazim-based fungicides, resulting in residual carbendazim levels of approximately 0.110 ̶
Keyword: Bioremediation, carbendazim residue, fungal identification, fungicide tolerance, soil

Judul: Identifikasi Molekuler Trichoderma spp. dan Aktivitas Antagonisnya terhadap Fusarium oxysporum f.sp cubense
Abstrak: Trichoderma is a cosmopolitan fungus that widespread in the soil and rotten wood. Various species of Trichoderma have been used, as a producer of enzymes and other metabolites or as a biocontrol agent. Therefore, identification of Trichoderma strains become important. Until now, many identity culture Trichoderma in Indonesia have doubtful validity. Trichoderma concept changed from time to time. Significant efforts in formulating the concept of Trichoderma was first performed by Rifai in 1969 based approach to morphological characters. Trichoderma species are divided into 9 aggregates, namely T. piluliferum, T. polysporum, T. hamatum, T. koningii, T. aureoviride, T. harzianum, T. longibrachiatum, T. pseudokoningii, and T. viride. This concept was later revised by Bissett in 1991 with the introduction of section 5 (section) is section Trichoderma, section Longibrachiatum, section Saturnisporum, section Pachybasium, and section Hypocreanum. Along with the development of methods of DNA extraction and phylogenetic analysis of the fungus, identification of Trichoderma species have been changed from morfohology in to combination of morphology and phylogenetic analysis. The first, phylogenetic analysis approach of Trichoderma by Kindermann in 1998 using DNA sequence analysis of the ITS region to 85 strains of Trichoderma. Then, when the approach of a single gene can not be relied upon to distinguish some species that are morphologically similar, multigene analysis was able to distinguish the species. At this time locus used in phylogenetic analysis and species identification in Trichoderma has been established that, ITS, tef α-1, RPB2, and Endokitinase. Trichoderma research in Indonesia have been carried out, but only a few research that include diversity and taxonomic studies. Trichoderma diversity and taxonomic studies from Indonesia is important because it can serve as a model for other fungal diversity studies. Therefore, this study aims to identify the 27 accession numbers Trichoderma collection of LIPIMC and IPBCC derived from litter and soil in Indonesia through a variety of phylogenetic approaches two genes (ITS and tef α-1). In addition, this research also aimed to characterize the antagonistic activity of Trichoderma spp. against Fusarium oxysporum f.sp. cubense (Foc), causes Fusarium wilt disease in bananas, because of the demands of the community to develop a biocontrol Foc agent. Identification of Trichoderma started early stages by performing morphological characterization. Colonies character observed in 5 days that were incubated at room conditions. After that, the microscopic preparations were made by using the method of Riddle and preparations were observed under a microscope Olympus BX53. Colony characters and microscopic characters are recorded as a material for morphological identification. Molecular phylogenetic analysis was started by growing Trichoderma isolates on media Potato Dextrose Broth (PDB) and incubated at 27˚C for 3-5 days. DNA extraction using PhythopureTM DNA Extraction Kit (GE Healthcare, UK), and then proceed with the ITS region amplification primer pair ITS4 (5'-TC CTCCGCTTATATATGC-3') and ITS5 (5'-GGAAGTAAAAGTCGTAACAA GG-3'), and α tef -1 (translation elongation factor-1 α) with primer tef1-fw (5'-GT GAGCGTGGTATCACCATCG-3 ') and tef1-rev (5'-GCCATCCTTGGAGACC AGC-3'). DNA sequencing is done by sending the product to FirstBASE (Malaysia). DNA sequences were analyzed by PCR using the MEGA program (Molecular Evolution and Genetic Analysis) version 5.05. On this analysis, kinship was
Keyword: biocontrol, Fusarium oxysporum f.sp cubense, phylogenetics, taxonomy, Trichoderma

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf