Electronic Theses and Dissertation

Tanaman kopi (Coffea sp) adalah salah satu tanaman yang penting bagi perekonomian
karena dapat memberikan kontribusi yang signifikan terhadap pendapatan devisa negara.
Menurut data dari Distanbun Aceh 2021, produksi kopi di Aceh mencapai 67,372 ton dan
mengalami penurunan pada tahun 2022 yaitu 64,247 ton. Penurunan jumlah produksi ini
disebabkan oleh permasalahan seperti infeksi penyakit yang berdampak pada hasil produksi
kopi. Salah satu penyakit yang menginfeksi tanaman kopi yaitu penyakit jamur akar putih
yang dapat membuat produksi tanaman kopi menurun. Penyakit jamur akar putih (white root
disease) merupakan penyakit utama pada beberapa tanaman perkebunan seperti karet, pala,
kopi. Kehilangan yang disebabkan penyakit tersebut dapat mencapai 70% pada pala dan 3-
15% karet. oleh sebab itu penyakit ini perlu dikendalikan. Petani kopi saat ini sering
menggunakan pestisida kimia sintetik akan tetapi dampak negatif yang ditimbulkan sangat
berbahaya baik terhadap manusia maupun lingkungan. Sehingga diperlukan teknik
pengendalian yang ramah lingkungan dengan memanfaatkan agens hayati seperti bakteri
endofit. Peneltian ini bertujuan mengeksplorasi serta menguji potensi bakteri endofit asal
kopi sebagai agens antagonis terhadap penyebab penyakit jamur akar putih pada kopi in
vitro.
Penelitian ini dilaksanakan di Laboratorium Ilmu Penyakit Tumbuhan, Fakultas
Pertanian, Universitas Syiah Kuala, Banda Aceh, dimulai sejak Bulan desember 2023
sampai Agustus 2024. Sampel diambil dari kebun kopi rakyat Aceh Tengah, terdiri dari akar,
ranting dan daun. Isolasi bakteri endofit ditumbuhkan pada media NA, sedangkan isolasi
JAP pada media PDA dan dilakukan karakterisasi bakteri endofit serta patogen secara
makroskopis dan mikroskopis, kemudian dilakukan uji dual culture terhadap Rigidoporus
sp. dengan menggunakan Rancangan Acak Lengkap (RAL) non-faktorial 7 perlakuan dan 4
ulangan, sehingga diperoleh 56 unit percobaan. Diamati juga mekanisme daya hambat
bakteri endofit dalam menekan Rigidoporus sp.
Hasil penelitian menunjukkan bahwa, terdapat 17 isolat bakteri endofit berhasil diisolasi
dari tanaman kopi, dengan 9 isolat berasal dari akar, 4 isolat dari ranting, dan 4 isolat dari
daun. Setelah dilakukan uji patogenisitas pada tanaman tembakau, 10 isolat menunjukkan
gejala nekrotik pada daun tembakau menandakan isolat tersebut bersifat patogen, sedangkan
7 isolat tidak menunjukkan gejala nekrotik berarti non patogen/endofit. Pada uji dual culture
terdapat 2 Isolat bakteri endofit yang berhasil menekan pertumbuhan JAP dan memiliki
persentase daya hambat di atas 50% yaitu kode isolat D3 66.92 % dan D4 75,00%.
Mekanisme bakteri endofit dalam menekan pertumbuhan JAP antara lain antibiosis dan
kompetisi ruang.

Coffee (Coffea sp.) is one of the most important crops for the economy as it can contribute significantly to the country's foreign exchange earnings. because it can make a significant contribution to the country's foreign exchange earnings. According to data from Distanbun Aceh 2021, coffee production in Aceh reached 67,372 tons and decreased in 2022 to 64,247 tons. decreased in 2022, namely 64,247 tons. This decrease in production caused by problems such as disease infections that have an impact on coffee production. coffee production. One of the diseases that infect coffee plants is white root fungus disease, which can make coffee plant production decline. which can make coffee plant production decrease. White root fungal disease (white root disease) is a major disease in several plantation crops such as rubber, nutmeg, coffee. Losses caused by the disease can reach 70% in nutmeg and 3- 15% in rubber. 15% rubber. therefore this disease needs to be controlled. Coffee farmers currently often use synthetic chemical pesticides but the negative impacts are very dangerous both to humans and the environment. harmful to both humans and the environment. So that an environmentally friendly control technique is needed control techniques that are environmentally friendly by utilizing biological agents such as endophytic bacteria. endophytes. This research aims to explore and test the potential of endophytic bacteria from as an antagonistic agent against the cause of white root fungus disease in coffee in vitro This research was conducted at the Laboratory of Plant Disease Science, Faculty of Agriculture, Syiah Kuala University, Banda Aceh. Agriculture, Syiah Kuala University, Banda Aceh, starting from December 2023 until August 2024. Samples were taken from the coffee plantation of Central Aceh people, consisting of roots, twigs and leaves. Isolation of endophytic bacteria grown on NA media, while isolation of JAP on PDA media and carried out. JAP on PDA media and characterization of endophytic bacteria and pathogens was carried out macroscopically and microscopically. macroscopically and microscopically, then dual culture tests were carried out against Rigidoporus sp. using a non-factorial Completely Randomized Design (CRD) with 7 treatments and 4 replications, resulting in 56 experimental units. replications, resulting in 56 experimental units. It was also observed that the inhibition mechanism of endophytic bacteria in suppressing Rigidoporus sp. The results showed that there were 17 isolates of endophytic bacteria successfully isolated from coffee plants, with 9 isolates from roots, 4 isolates from twigs, and 4 isolates from coffee plants. from coffee plants, with 9 isolates coming from roots, 4 isolates from twigs, and 4 isolates from leaves. leaves. After pathogenicity testing on tobacco plants, 10 isolates showed necrotic symptoms on tobacco leaves. necrotic symptoms on tobacco leaves indicating that the isolate is pathogenic, while 7 isolates did not show necrotic symptoms on tobacco leaves. 7 isolates do not show necrotic symptoms means non-pathogenic / endophytic. In the dual culture test There are 2 isolates of endophytic bacteria that successfully suppress the growth of JAP and have a percentage inhibition above 50%, namely percentage of inhibition above 50%, namely isolate code D3 66.92% and D4 75.00%. The mechanism of endophytic bacteria in suppressing JAP growth includes antibiosis and space competition.