Uji potensi antagonis bakteri endofit Bacillus cereus dan Bacillus megaterium terhadap jamur patogen Fusarium oxysporum penyebab penyakit layu daun cabai rawit (Capsicum frustescens L.).

INDONESIA:

Kebutuhan cabai rawit di Indonesia sangat tinggi, namun sektor budidaya masih mengalami kendala akibat serangan penyakit tanaman yang berdampak pada penurunan hasil produksi. Layu Fusarium merupakan salah satu penyakit penting pada cabai rawit. Salah satu upaya yang dapat menekan pertumbuhan patogen secara ramah lingkungan adalah dengan memanfaatkan bakteri endofit. Penelitian ini bertujuan unutuk mengetahui potensi bakteri endofit Bacillus cereus dan Bacillus megaterium sebagai agen antagonis yang mampu menekan pertumbuhan jamur patogen Fusarium oxysporum secara in vitro dan in vivo. Penelitian ini termasuk penelitian eksperimental menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 6 ulangan, mencakup perlakuan kontrol (tanpa bakteri endofit), perlakuan penambahan bakteri endofit Bacillus cereus, perlakuan penambahan bakteri endofit Bacillus megaterium, dan perlakuan kombinasi dengan menggunakan kedua bakteri endofit. Metode penelitian pada uji in vitro menggunakan dual culture assay, sedangkan pada uji in vivo menggunakan metode perendaman akar bibit tanaman cabai rawit. Hasil penelitian uji in vitro menunjukkan bahwa persentase daya hambat Bacillus cereus terhadap pertumbuhan Fusarium oxysporum sebesar 23%, perlakuan kombinasi sebesar 23%, dan presentase daya hambat paling besar adalah dengan B. megaterium sebesar 35%. Pada pengamatan mikroskopis, hifa Fusarium oxysporum mengalami abnormal akibat aktivitas antibiosis bakteri. Hasil pengujian in vivo menunjukkan bahwa masa inkubasi penyakit layu Fusarium pada tanaman cabai rawit paling lama terdapat pada perlakukan bakteri endofit Bacillus megaterium yaitu 16 hsi, sedangkan paling cepat pada perlakuan kombinasi kedua endofit yaitu 1 hsi. Pengamatan tinggi tanaman cabai rawit paling tinggi mencapai rata-rata 7,1 cm (28 hsi) pada perlakuan yang menggunakan isolat B. megaterium., sedangkan paling rendah terdapat pada perlakuan menggunakan Bacillus cereus yaitu 3,4 cm (28 hsi). Pada pengamatan kejadian penyakit, rata-rata kejadian penyakit masing-masing perlakuan tidak terdapat pengaruh yang nyata. Adapun intensitas penyakit paling tinggi terdapat pada perlakuan bakteri endofit Bacillus cereus dengan persentase 87,78%, sedangkan paling rendah terdapat pada perlakuan Bacillus megaterium yaitu 39,52%. Kedua bakteri genus Bacillus ini berpotensi sebagai agen antagonis yang ramah lingkungan untuk keperluan pengendalian penyakit tanaman.

ENGLISH:

The need of cayenne pepper in Indonesia is very high, but the cultivation sector is still experiencing obstacles due to plant diseases that impact on the decline in production. Fusarium Wilt is one of the important diseases in cayenne pepper. One of the efforts that can suppress the growth of pathogens in an environmentally friendly way is to utilize endophytic bacteria. The research aims at determining the potential of endophytic bacteria of Bacillus cereus and Bacillus megaterium as an antagonistic agent that is able to suppress the growth of Fusarium oxysporum pathogens fungal in vitro and in vivo. The research included an experimental study using Completely Randomized Design with 4 treatments and 6 replications, including control treatment (without endophytic bacteria), treatment of Bacillus cereus endophytic bacteria, addition of endophytic bacteria of Bacillus megaterium, and combination treatment with both endophytic bacteria. The methods of research on in vitro test used dual culture assay, while in vivo test used soaking method of root of cayenne pepper seedlings. The results of in vitro assay showed that the percentage of inhibitory capacity of Bacillus cereus on Fusarium oxysporum growth was 23%, the combination treatment was 23%, and the biggest inhibitory percentage was B. megaterium of 35%. In microscopic observation, Fusarium oxysporum hyphae experienced abnormal due to bacterial antibiotic activity. In vivo test results showed that Fusarium withered incubation period in cayenne pepper plant was in treating endophyte bacteria of Bacillus megaterium, it was 16 hsi, while the fastest in treatment of combination of endophyte was 1 hsi. The highest observation of cayenne pepper plant reached an average of 7.1 cm (28 hsi) in the treatment by using B. megaterium isolate, while the lowest was in treatment with Bacillus cereus, it was 3.4 cm (28 hsi). In the observation of disease incidence, the average of disease incidence there was no real influence of each treatment. The highest disease intensity was found in endophyte bacteria treatment of Bacillus cereus with 87.78% percentage, while the lowest was in Bacillus megaterium treatment which was 39.52%. Both of these genus bacteria of Bacillus had the potential as an environmentally friendly antagonist agent for the plant disease control needs.