Judul: Fungal Identification of Colletotrichum sp. from Red Chili (Capsicum annuum L.) Seeds and its Elimination Technique with Electroteraphy
Abstrak: Anthracnose is one of the important diseases in chili plants. The antrachnose fungus is also known to be seed-borne. Control measures applied to the seed phase is an effective strategy to reduce initial number of inoculum and the risk of transmission during planting. Electrotherapy shows potential as an alternative for controlling pathogens associated with seeds. This study aims to identify the fungus isolated from chilies with anthracnose symptom and to eliminate the pathogen from its seeds using electrotherapy technique without reducing the quality of seeds. The fungal colony on PDA was white, colony diameter rate at 3.71 mm per day. The hyphae was septate and branched, bearing cylindrical conidia with one of the edges tapered and aseptate, conidia length around 5.69 -9.78 µm and widths ranging from 2.30-3.19 µm. PCR amplification using a specific primer of Colletotrichum acutatum CaInt-2/ ITS4 showed DNA band size of ± 490 bp. Nucleotide analysis of PCR amplicon employing universal primers ITS5/ITS4 showed that CRSB isolates had 100% homology using contig results and 99.8% using forward fragments with nucleotide isolates Colletotrichum sp. in GenBank. Electrotherapy of healthy seeds and fungal with a DC 12 V 1 A electric current and 0.5 M NaCl concentration results in a treatment window at 20-25 minutes electrotherapy which can reduce the number of fungal colonies, but can maintain seed viability remains high. Electrotherapy for infected seeds at 20 and 25 minutes showed that seed viability was not so different., Antraknosa merupakan salah satu penyakit penting pada tanaman cabai. Cendawan penyebab antraknosa diketahui dapat bersifat terbawa benih. Pengendalian patogen yang diterapkan pada fase benih menjadistrategi yang efektif untuk menekan patogen ini sejak dini sehingga dapat mengurangi risiko penularan saat penanaman. Elektroterapi menunjukkan potensi sebagai alternatif untuk mengendalikan patogen terbawa benih. Penelitian ini bertujuan mengidentifikasi cendawan dari buah cabai bergejala antraknosa dan mengeliminasi patogen dari benih tersebut dengan teknik elektroterapi tanpa menurunkan kualitas benih. Koloni cendawan pada media PDA berwarna putih dengan pertumbuhan koloni 3.71 mm per hari, hifa bersekat dan bercabang, konidia silindris dengan salah satu ujungnya meruncing dan tidak bersekat, panjang konidia 5.69-9.78 µm dan lebar 2.30-3.19 µm. Amplifikasi PCR menggunakan primer spesifik Colletotrichum acutatum CaInt-2/ITS4 menunjukkan pita DNA berukuran ± 490 pb. Analisis nukleotida hasil amplifikasi PCR dengan primer universal ITS5/ITS4 menunjukkan isolat CRSB memiliki homologi 100% menggunakan hasil contig dan 99.8% menggunakan fragmen forward dengan nukleotida isolat Colletotrichum sp. yang ada pada GenBank. Elektroterapi benih sehat dan suspensi cendawan dengan arus listrik DC 12 V 1 A serta konsentrasi NaCl 0.5 M menghasilkan treatment window pada waktu elektroterapi 20-25 menit yang dapat menurunkan jumlah koloni cendawan, tetapi dapat mempertahankan viabilitas benih tetap tinggi.
Keyword: Era Lutfi, Antraknosa, Colletotrichum, Benih cabai, Elektroterapi