PEMANFAATAN Bacillus spp. DALAM PENGELOLAAN NEMATODA PURU AKAR Meloidogyne incognita PADA TANAMAN TERUNG

Zulaeha Rosita Gani, Prof. Tri Joko, S.P., M.Sc., Ph.D.

2025 | Tesis | S2 Fitopatologi

Nematoda puru akar (Meloidigyne incognita) merupakan nematoda parasit tanaman penting karena memiliki kisaran inang yang luas. Dampak penggunaan nematisida kimia untuk pengelolaan M. incognita mendorong pengembangan bionematisida yang lebih ramah lingkungan. Bacillus berpotensi untuk dikembangkan sebagai agen pengendali hayati M. incognita karena menurunkan kemampuan infeksi M. incognita. Penelitian ini bertujuan untuk melakukan skrining terhadap beberapa spesies Bacillus sebagai metode pengelolaan J2 M. incognita. Pengujian secara in vitro meliputi pengujian mortalitas dan repelensi. Hasil pengujian in vitro digunakan untuk memilih 4 isolat potensial kemudian dilanjutkan identifikasi secara molekular dan pengujian di greenhouse. Percobaan di greenhouse menggunakan Rancangan Acak Kelompok Lengkap (RAKL) yang terdiri dari 11 perlakuan dan 5 ulangan dengan 3 unit. Perlakuan terdiri dari kontrol, tanaman inokulasi M. incognita, tanaman isolat Bacillus, tanaman inokulasi M. incognita dan isolat Bacillus, dan tanaman inokulasi M. incognita dan nematisida kimia karbofuran. Hasil penelitian menunjukkan bahwa isolat Bacillus mampu menyebabkan mortalitas dan memiliki kemampuan repelensi terhadap J2 M. incognita. Identifikasi berbasis gen 16S rRNA menunjukkan bahwa isolat berkerabat dekat dengan B. velezensis, B. tropicus, dan B. thuringiensis. Pengujian di Greenhouse menunjukkan bahwa aplikasi Bacillus mampu menurunkan jumlah puru, jumlah egg mass, tingkat kerusakan akar dan jumlah populasi J2 M. incognita di akar pada tanaman terung dibandingkan kontrol. Akan tetapi aplikasi Bacillus belum mampu meningkatkan tinggi tanaman, panjang akar dan bobot basah akar.

Root-knot nematode (Meloidigyne incognita) is an important plant parasitic nematode because it has a wide host range. The impact of using chemical nematicides for the management of M. incognita encourages the development of bionematicides that are more environmentally friendly. Bacillus has the potential to be developed as a biological control agent of M. incognita because it reduces the ability of M. incognita infection. This study aims to screen several Bacillus species as a method of managing J2 M. incognita. In vitro testing included mortality and repellency. The results of in vitro testing were used to select 4 potential isolates, followed by molecular identification and greenhouse testing. The greenhouse experiment used a completely randomised design consisting of 11 treatments and 5 replicates with 3 units. Treatments consisted of control, plants inoculated with M. incognita, plants with Bacillus, plants inoculated with M. incognita and Bacillus, and plants inoculated with M. incognita and carbofuran chemical nematicide. The results showed that Bacillus isolates were able to cause mortality and had repellency ability against J2 M. incognita. 16S rRNA gene-based identification showed that the isolates were closely related to B. velezensis, B. tropicus, and B. thuringiensis. Greenhouse tests showed that Bacillus application was able to reduce the number of bullets, the number of egg masses, the level of root damage and the number of J2 M. incognita populations in the roots of eggplant plants compared to the control. However, Bacillus application has not been able to increase plant height, root length and root wet weight.

Kata Kunci : Bacillus, biocontrol, mortalitas, populasi, repelensi