Electronic Theses and Dissertation

Fusarium sp. merupakan salah satu patogen tular tanah yang menyebabkan penyakit layu pada tanaman, termasuk tanaman pala (Myristica fragrans Houtt). Cendawan ini mampu bertahan di dalam tanah hingga puluhan tahun dan berkembang pesat dalam kondisi lingkungan yang lembab dan asam. Pengendalian alternatif yang ramah lingkungan dapat dilakukan melalui pemanfaatan cendawan rhizosfer sebagai agens hayati antagonis. Banyak jenis cendawan yang berasosiasi di rizosfer tanaman pala, beberapa diantaranya memiliki kemampuan untuk menghambat pertumbuhan Fusarium sp. Penelitian ini bertujuan untuk mengeksplorasi cendawan rizosfer pada tanaman pala dan mengetahui jenis cendawan rizosfer yang paling berpotensi terhadap Fusarium sp. in vitro.
Penelitian ini dilakukan Laboratorium Ilmu Penyakit Tumbuhan, Fakultas Pertanian, Universitas Syiah Kuala, Darussalam-Banda Aceh, serta pengambilan sampel dilakukan di lima lokasi berbeda di Kabupaten Aceh Selatan, yaitu desa Peunelop, Hulu Pisang, Gunung Ketek, Alur Simerah, dan Lubuk Ayu. Penelitian terdiri dari survey di lapangan, proses pengambilan sampel, dan isolasi cendawan rizosfer secara In-vitro. Penelitian ini terdiri dari 3 tahapan, tahap pertama adalah isolasi cendawan rizosfer dan cendawan patogen. Pemilihan lahan penelitian ini dilakukan dengan menggunakan metode purposive sampling yaitu penentuan lokasi secara sengaja berdasarkan pertimbangan-pertimbangan tertentu. Penentuan titik pengambilan sampel didasarkan pada luas area lahan serta jumlah tanaman yang terdapat di lokasi tersebut. Tahap kedua karakterisasi cendawan rizosfer dan cendawan patogen, serta uji patogenesitas cendawan rizosfer. Tahap ketiga adalah uji dual culture antara isolat cendawan rizosfer non patogen dengan Fusarium sp. in vitro. Penelitian ini menggunakan rancangan acak lengkap (RAL) non factorial. Hasil data uji persentase daya hambat cendawan rizosfer terhadap patogen Fusarium sp. yang diperoleh akan dianalisis menggunakan ANOVA. Apabila data menunjukkan pengaruh nyata terhadap Fhit maka dilanjutkan dengan uji duncan multiple range test (DMRT) pada taraf 5%. Peubah diamati meliputi karakteristik secara makroskopis dan mikroskopis dan persentase daya hambat cendawan rizosfer terhadap patogen Fusarium sp.
Hasil penelitian menunjukkan bahwa 34 isolat rizosfer asal pertanaman pala. Berdasarkan hasil identifikasi bahwa, terdapat 13 isolat cendawan yang tidak menimbulkan gejala nekrotik pada benih padi, hal yang mencirikan isolat tersebut bersifat non patogen. Sedangkan 21 isolat lainnya bersifat patogen yang menyebabkan gejala nekrotik, serta terjadinya pembusukan pada benih. Semua isolat menunjukkan aktivitas antagonistik dengan variasi daya hambat. Isolat dengan persentase daya hambat tertinggi adalah Aspergillus sp. 2 (87,78%). Mekanisme penghambatan yang teridentifikasi meliputi kompetisi ruang dan nutrisi, pembengkakan hifa patogen, hifa keriting, dan abnormal. Penelitian ini membuktikan bahwa adanya cendawan rizosfer tanaman pala yang memiliki potensi sebagai agens hayati dalam mengendalikan Fusarium sp.

Fusarium sp. is a soil-borne pathogen that causes wilt in plants, including nutmeg (Myristica fragrans Houtt). This fungus can survive in the soil for decades and thrives in humid, acidic conditions. An environmentally friendly alternative control method is the use of rhizosphere fungi as antagonistic biological agents. Many species of fungi are associated with the rhizosphere of nutmeg plants, some of which have the ability to inhibit the growth of Fusarium sp. This study aimed to explore rhizosphere fungi in nutmeg plants and determine the most effective rhizosphere fungi against Fusarium sp. in vitro. This research was conducted by the Plant Pathology Laboratory, Faculty of Agriculture, Syiah Kuala University, Darussalam-Banda Aceh, and sampling was conducted at five different locations in South Aceh Regency: Peunelop, Hulu Pisang, Gunung Ketek, Alur Simerah, and Lubuk Ayu villages. The study included a field survey, sampling, and in vitro isolation of rhizosphere fungi. This research consisted of three stages. The first stage was the isolation of rhizosphere fungi and pathogenic fungi. The research site was selected using purposive sampling, which involves deliberately selecting locations based on specific considerations. Sampling points were determined based on the land area and the number of plants present at the site. The second stage involved characterization of rhizosphere and pathogenic fungi, as well as testing for rhizosphere fungal pathogenicity. The third stage was a dual culture test between non-pathogenic rhizosphere fungal isolates and Fusarium sp. in vitro. This study used a completely randomized design (CRD) with a non-factorial design. The results of the rhizosphere fungal inhibitory percentage test against Fusarium sp. were analyzed using ANOVA. If the data showed a significant effect on Fhit, the Duncan Multiple Range Test (DMRT) was performed at the 5% level. Observed variables included macroscopic and microscopic characteristics and the rhizosphere fungal inhibitory percentage against Fusarium sp. The results showed that 34 rhizosphere isolates from nutmeg plantations. Based on the identification results, there were 13 fungal isolates that did not cause necrotic symptoms in rice seeds, which characterizes these isolates as non-pathogenic. Meanwhile, the other 21 isolates were pathogenic, causing necrotic symptoms and seed rot. All isolates showed antagonistic activity with varying inhibitory power. The isolate with the highest percentage of inhibitory power was Aspergillus sp. 2 (87.78%). The identified inhibitory mechanisms included competition for space and nutrients, swelling of pathogenic hyphae, curly hyphae, and abnormality. This study proves that the presence of nutmeg plant rhizosphere fungi has the potential as a biological agent in controlling Fusarium sp.