Electronic Theses and Dissertation

Tanaman nilam memiliki potensi ekonomi yang sangat signifikan. Namun, dalam budidayanya, tanaman nilam sering mengalami serangan penyakit fungal yang dapat mengurangi kualitas dan kuantitas hasil panen. Sclerotium rolfsii merupakan salah satu jamur patogen tular tanah yang dapat menyebabkan penyakit busuk batang pada tanaman nilam. Infeksi yang ditimbulkan dapat mengakibatkan pembusukan jaringan hingga kematian tanaman, dengan tingkat penurunan hasil panen yang dilaporkan mencapai 60%. Pengendalian patogen ini umumnya dilakukan menggunakan fungisida kimia, namun penggunaannya semakin dihindari karena dampak negatif terhadap lingkungan. Alternatif yang dapat diterapkan adalah pengendalian hayati
dengan memanfaatkan bakteri endofit yang hidup dalam jaringan tanaman. Penelitian ini bertujuan untuk memperoleh bakteri endofit dari tanaman nilam Aceh varietas Tapaktuan yang berpotensi sebagai agen antifungi terhadap S. rolfsii. Isolasi bakteri endofit dilakukan dari akar, batang, dan daun tanaman nilam dengan menggunakan metode pengenceran, sedangkan uji aktivitas antifungi dilakukan dengan metode kultur ganda. Sebanyak 23 isolat bakteri endofit berhasil diisolasi dari tanaman nilam, di mana 11 isolat menunjukkan aktivitas antifungi yang sangat kuat. Isolat paling potensial bertutur-turut adalah DT-7 (28,7 mm), BT-6 (27,68 mm), DT-3 (25,2 mm), BT-3 (23,4 mm), AT-7 (23,1 mm), BT-8 (23,03 mm), BT-7 (22,23 mm), AT-2 (21,48 mm), AT-4 (21,3 mm), BT-4 (21,03 mm), dan AT-5 (20,13 mm). Hasil penelitian menunjukkan bahwa bakteri endofit dari tanaman nilam Aceh varietas Tapaktuan memiliki aktivitas antifungi terhadap Sclerotium rolfsii.
Kata kunci: Bakteri endofit, antifungi, nilam Aceh, Sclerotium rolfsii

Patchouli plants have very significant economic potential. However, in its cultivation, patchouli plants often experience fungal disease attacks that can reduce the quality and quantity of the harvest. Sclerotium rolfsii is a soil-borne pathogenic fungus that can cause stem rot disease in patchouli plants. The infection caused can lead to tissue rot and even plant death, with reported yield reductions reaching 60%. Control of this pathogen is generally carried out using chemical fungicides, but their use is increasingly avoided due to negative impacts on the environment. An alternative that can be applied is biological control by utilizing endophytic bacteria that live within plant tissues. This research aims to obtain endophytic bacteria from Aceh patchouli plants of the Tapaktuan variety that have the potential to act as antifungal agents against S. rolfsii. Isolation of endophytic bacteria was carried out from the roots, stems, and leaves of patchouli plants using the dilution method, while the antifungal activity test was carried out using the dual culture method. A total of 23 endophytic bacterial isolates were successfully isolated from patchouli plants, of which 11 isolates showed very strong antifungal activity. The ten most potential isolates were DT-7 (28,7 mm), BT-6 (27,68 mm), DT-3 (25,2 mm), BT-3 (23,4 mm), AT-7 (23,1 mm), BT-8 (23,03 mm), BT-7 (22,23 mm), AT-2 (21,48 mm), AT-4 (21,3 mm), BT-4 (21,03 mm), and AT5 (20,13 mm). The results of this study indicate that endophytic bacteria from Aceh patchouli variety Tapaktuan have antifungal activity against Sclerotium rolfsii. Keywords: Endophytic bacteria, antifungal, Aceh patchouli, Sclerotium rolfsii