Judul: Potential inhibition of phylospheric actinomycetes of Liliaceae plants against Colletotrichum acutatum
Abstrak: Cabai merupakan salah satu komoditas unggulan hortikultura yang penting bagi masyarakat Indonesia. Antraknosa merupakan penyakit utama peyebab rendahnya produktivitas cabai di Indonesia. Antraknosa disebabkan oleh genus Colletotrichum dan spesies yang paling banyak menyerang cabai di Indonesia saat ini adalah Colletotrichum acutatum. Pengendalian antraknosa secara kimiawi menggunakan fungisida kontak dan sistemik secara intensif. Untuk mengatasi dampak negatif penggunakaan fungisida, diperlukan alternatif pengendalian hayati. Salah satu agens hayati yang digunakan yaitu aktinomiset. Penelitian ini bertujuan mendapatkan isolat aktinomiset filosfer Liliaceae yang berpotensi mengendalikan C. acutatum. Tahapan penelitian yang dilakukan meliputi perbanyakan isolat aktinomiset filosfer Liliaceae dan C. acutatum, karakterisasi morfologi aktinomiset, uji antagonis aktinomiset terhadap C. acutatum, dan identifikasi aktinomiset secara molekuler. Karakterisasi aktinomiset dilakukan dengan menggunakan media yeast starch agar dan international streptomyces project 2. Sebanyak 21 isolat dilakukan uji antagonis secara in vitro dengan metode dual cultre menggunakan rancangan acak lengkap (RAL). Identifikasi isolat aktinomiset filosfer Liliaceae terbaik secara molekuler dengan Teknik PCR menggunakan primer universal untuk yaitu 27F dan 16Sact1114R. Persentase tingkat hambatan relatif (THR) aktinomiset terhadap C. acutatum sebesar 14,32-47,66%. Dua isolat dengan persentase penghambatan tertinggi terhadap penyakit antraknosa secara in vitro adalah ACW23 dan BBH11 sebesar 47,66% dan 44,79%. Hasil identifikasi molekuler kedua isolat tersebut memiliki kemiripan dengan Propionicicella superfundia dan Enemella dayhoffiae, Chili is one of the leading horticultural commodities that is important for the people of Indonesia. Anthracnose is the main disease that causes low chili productivity in Indonesia. Anthracnose is caused by various species of Colletotrichum, and in Indonesia especially by Colletotrichum acutatum. Chemical control of anthracnose used contact and systemic fungicides intensively. To overcome the negative impact of fungicide use, alternative biological control is needed. One of the biological control agents candidates used is actinomycetes. This study aims to obtain phyllospheric actinomycetes Liliaceae isolates that can potentially control C. acutatum. The stages of the research conducted include the propagation of phyllospheric actinomycetes Liliaceae isolates and C. acutatum, morphological characterization of actinomycetes, actinomycetes antagonistic test against C. acutatum, and molecular identification of actinomycetes. Morphological characterization of actinomycetes was conducted with yeast starch agar media and international streptomyces project 2 media. A total of 21 isolates were tested for antagonism in vitro with the dual culture method using a completely randomized design. Identification of the best phyllospheric actinomycetes Liliaceae isolates molecularly by polymerase chain reaction technique using universal primers for 27F and 16Sact1114R. The percentage of relative inhibition rate of actinomycetes against C. acutatum was 14.32-47.66%. Two isolates with the highest percentage of inhibition against anthracnose disease in vitro were ACW23 and BBH11 at 47.66% and 44.79%. The results of molecular identification of the two isolates are similar to Propionicicella superfundia and Enemella dayhoffiae.
Keyword: antraknosa, cabai, pengendalian hayati, Enemella dayhoffiae, Propionicicella superfundia