Perubahan Komposisi Mikrobiota Akar Tanaman Tebu yang Diinokulasi Jamur Mikoriza Arbuskular

ZULFA FATMAWATI, Dr. Ir. Jaka Widada, M.P.; Ir. Donny Widianto, Ph.D.

2021 | Tesis | MAGISTER BIOTEKNOLOGI

Mikrobiota akar merupakan mikroorganisme menguntungkan yang berinteraksi dengan tanaman inang tanpa menyebabkan gangguan atau kerusakan pada tanaman tesebut. Inokulasi Jamur Mikoriza Arbuskular (JMA) pada daerah akar mampu mengubah komposisi mikrobiota akibat eksudat yang dikeluarkan mengandung gula, karboksilat, dan asam amino yang tinggi. Penelitian ini bertujuan untuk mengetahui perubahan komposisi bakteri perakaran tanaman tebu yang diinokulasi jamur mikoriza arbuskular. Tanaman tebu varietas Bululawang ditanam di 3 jenis tanah (Alfisol, Inceptisol, dan Entisol) dalam polybag. Inokulasi spora jamur mikoriza sebanyak 3g/tanaman dilakukan pada saat pindah tanam. Analisis tanah berupa pengukuran pH, kapasitas tukar kation, ketersediaan P, dan C-organik. Ketergantungan tanaman terhadap JMA diukur dengan membandingkan berat kering tanaman tebu yang diinokulasi dengan yang tidak diinokulasi. Analisis komposisi bakteri perakaran tebu dilakukan dengan metode Next Generation Sequencing (NGS) pada 16SrRNA region V3-V4. Hasil penelitian menunjukkan tingkat ketergantungan tanaman tebu terhadap JMA di tanah alfisol, inceptisol, dan Entisol berturut-turut adalah 46,9, 34,98, dan 48,75%. Kelimpahan filum Firmicutes mengalami kenaikan rata-rata di tanah alfisol, inceptisol dan entisol bertutur-turut adalah 15,05, 0,75 dan 2,25%. Penurunan kelimpahan terjadi di filum Actinobacteria dengan rata-rata nilai 0,98, 1,45 dan 0,13%. Kenaikan rata-rata filum Proteobacteria beruturut-turut terjadi di tanah inceptisol dan entisol sebesar 12,65 dan 8,25%, namun turun 2,88% di tanah alfisol. Keseluruhan data yang diperoleh menunjukkan bahwa tanaman tebu memiliki ketergantungan tinggi terhadap JMA, dan inokulasi JMA merubah komposisi bakteri perakaran tebu.

Root microbiota are beneficial microorganisms that interact with host plants without causing disruption or damage to the host. Arbuscular Mycorrhizal Fungi (AMF) inoculation in plants has been known to have an effect on the surrounding microbiome composition due to its ability to alter the production of root exudates, including sugar, carboxylates, and amnio acid. This study aimed to observe the change in root bacteria composition in sugarcane (Saccharum officinarum) after AMF inoculation. Observation was done using Bululawang cultivar grown in polybags with three different soil types (alfisols, inceptisols, and entisols). For the inoculation, 3 grams of AMF spores was applied during transplantation. Parameters analyzed were soil pH, cation exchange capacity, as well as phosphate and organic carbon availability. Plant mycorrhizal dependency was measured through comparing plant dry weight of inoculated and non inoculated. Finally, root bacteria composition analysis was done using Next Generation Sequencing method (NGS) on V3-V4 16SrRNA regions. The Results showed the mycorrhizal dependency in alfisol, inceptisol, and Entisol soil were 46,9, 34,98, and 48,75% respectively. The abundance of the phylum Firmicutes in alfisol, inceptisol and Entisol soil were increased 15,05, 0,75 and 2,25%. There was a decrease in the abundance of Actinobacteria with an average value of 0,98, 1,45 and 0,13%. The increase of Proteobacteria phyla respectively occurred in inceptisol and Entisol soil of 12,65 and 8,25%, but decreased 2,88% in alfisol soil. Based on the result indicated that sugarcane plants had a high dependence on JMA, and JMA inoculation changed the composition of root bacteria.

Kata Kunci : Jamur Mikoriza Arbuskular, Mikrobiota, Tanah, Tebu, NGS