Eksplorasi Bakteri Filoplan Daun Karet dan Potensinya sebagai Agens Hayati terhadap Pestalotiopsis sp. Penyebab Penyakit Gugur Daun - Oktarianti, Sherly; Rianto, Fadjar; Syahputra, Edy (STKIP Singkawang, 2024)
Karet di Indonesia merupakan salah satu peyumbang yang cukup besar terhadap devisa negara di sektor perkebunan. Upaya pengendalian digunakan untuk menekan penyakit gugur daun, Pengendalian hayati dengan memanfaatkan musuh alami diketahui dapat menekan pertumbuhan patogen. Diperlukan pencarian musuh alami yang efektif dalam mengendalikan patogen. Eksplorasi agens hayati merupakan langkah awal pada pengembangan pengendalian hayati. Penelitian ini bertujuan untuk eksplorasi bakteri filoplan daun karet yang berpotensi sebagai agens hayati terhadap Pestalotiopsis sp. penyebab penyakit gugur daun karet. Penelitian dilakukan di Laboratorium Penyakit Tanaman Fakultas Pertanian Universitas Tanjungpura Pontianak. Pelaksanaan penelitian dimulai dari eksplorasi bakteri filoplan pengambilan sampel bakteri filoplan tanaman karet, selanjutnya dilakukan isolasi dengan media Nutrient Broth, pemurnian dengan media Nutrient Agar dan identifikasi bakteri filoplan. Variabel yang diamati meliputi daya antagonisme bakteri filoplan terhadap Pestalotiopsis sp. dengan uji dual culture, uji reaksi gram dan respon hipersensitivitas (HR). Hasil eksplorasi mikroba filosfer pada daun karet ditemukan 6 isolat bakteri yang memiliki sifat antagonis dari 36 isolat yang ditemukan dilapangan yaitu FK10, FK11, FK21, FK24 dan FK26. Terdapat 4 isolat yang memiliki daya hambat dibawah 60 % yaitu FK2, FK10, FK11 dan FK24. Sedangkan 2 isolat memiliki daya hambat diatas 60% yaitu isolat FK21 dan FK26. Persentase penghambat tertinggi diperlihatkan isolat FK26 yaitu 61,2%. Isolat FK2, FK21, FK24 dan FK26 tidak bersifat patogen bagi tanaman pada hasil uji HR.Kata Kunci: Agens Pengendali Hayati; Bakteri Filoplan; Pestalotiopsis sp.; Tanaman KaretExploration of Rubber Leaf Filoplan Bacteria and Its Potential as a Biological Agent against Pestalotiopsis sp. Causes of Leaf Loss DiseaseABSTRACTRubber in Indonesia is a fairly large contributor to the country's foreign exchange in the plantation sector. Control efforts are used to suppress leaf fall disease. Biological control using natural enemies is known to suppress the growth of pathogens. It is necessary to search for natural enemies that are effective in controlling pathogens. Exploration of biological agents is the first step in the development of biological control. This research aims to explore rubber leaf phylloplan bacteria which have potential as biological agents against Pestalotiopsis sp. causes of rubber leaf fall disease. The research was conducted at the Plant Disease Laboratory, Faculty of Agriculture, Tanjungpura University, Pontianak. The research began with exploration of phylloplan bacteria, taking samples of phylloplan bacteria from rubber plants, then isolation using Nutrient Broth media, purification using Nutrient Agar media and identification of phylloplan bacteria. The variables observed included the antagonism of phylloplan bacteria against Pestalotiopsis sp. with dual culture test, gram reaction test and hypersensitivity response (HR). The results of exploration of phyllosphere microbes on rubber leaves found 6 bacterial isolates that had antagonistic properties from 36 isolates found in the field, namely FK10, FK11, FK21, FK24 and FK26. There were 4 isolates that have an inhibitory power below 60%, namely FK2, FK10, FK11 and FK24. Meanwhile, 2 isolates had an inhibitory power above 60%, namely isolates FK21 and FK26. The highest percentage of inhibitors was shown by isolate FK26, namely 61.2%. Isolates FK2, FK21, FK24 and FK26 were not pathogenic for plants in the HR test results.