Utami, Afrida Rachma (2019) Potensi Rizobakteri Dan Senyawa Metabolit Sekundernya Dalam Mengendalikan Penyakit Busuk Lunak Pada Umbi Kentang (Erwinia sp.). Sarjana thesis, Universitas Brawijaya.
Abstract
Kentang (Solanum tuberosum L.) merupakan salah satu komoditas yang dapat diandalkan di Indonesia, namun terjadi kendala dalam peningkatan produksi umbi kentang. Salah satunya adalah serangan Erwinia sp. yang menyebabkan penyakit busuk lunak pada umbi kentang. Upaya pengendalian dapat dilakukan dengan memanfaatkan agens pengendali hayati (APH) dengan bakteri rizosfer. Namun penggunaan APH memiliki kekurangan, salah satunya konsentrasi metabolit sekunder yang dihasilkan oleh APH tidak dapat diprediksi secara pasti. Penelitian bertujuan untuk mengetahui potensi agens hayati rizosfer UB forest dan potensi penggunaan metabolit sekunder bakteri rizosfer dalam menghambat pertumbuhan bakteri Erwinia sp. penyebab penyakit busuk lunak umbi kentang. Penelitian dilakukan di laboratorium penyakit tumbuhan 1 dan toksikologi pestisida, jurusan Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Unversitas Brawijaya, Malang pada bulan Januari hingga April 2019. Penelitian terdiri dari delapan tahapan: (1) Peremajaan isolat bakteri Erwinia sp. dan bakteri rizosfer UB forest (2) uji Patogenisitas (3) seleksi antagonis bakteri rizosfer UB forest terhadap Erwinia sp. (4) uji antagonis bakteri rizosfer UB forest terhadap Erwinia sp. secara in vitro (5) uji jenis antibiosis (6) ekstraksi metabolit sekunder bakteri rizosfer (7) Uji penghambatan metabolit sekunder terhadap Erwinia sp. secara in vitro (8) Uji penekanan penyakit busuk lunak pada umbi kentang oleh bakteri rizosfer dan senyawa metabolit sekundernya. Hasil seleksi dari 34 isolat bakteri rizosfer UB forest diperoleh 24 isolat bakteri yang bersifat antagonis terhadap patogen Erwinia sp. Semua isolat bakteri rizosfer memiliki indeks penghambatan (IP) lebih tinggi dibandingkan dengan perlakuan streptomisin sulfat meskipun isolat bakteri bersifat bakteriostatik sehingga terjadi penurunan IP dalam menghambat Erwinia sp. Dua isolat bakteri dengan IP tertinggi adalah isolat Bacillus sp. N3 dan Pseudomonas sp. N19. Hasil pengujian metabolit sekunder Bacillus sp. N3 dan Pseudomonas sp. N19 terhadap Erwinia sp. secara in vitro menunjukkan IP yang lebih rendah dibandingkan dengan pengujian antagonis menggunakan isolat bakteri. Adanya biomassa isolat bakteri Bacillus sp. N3 dan Pseudomonas sp. N19 tersebut dapat menambah produksi metabolit sekunder dalam menghambat Erwinia sp. Sedangkan pada penekanan penyakit busuk lunak pada umbi kentang, metabolit sekunder bakteri rizosfer lebih efektif digunakan dibandingkan dengan mengguakan isolat bakteri rizosfer. Hal tersebut dikarenakan isolat bakteri membutuhkan waktu dalam menghasilkan metabolit sekunder yang dapat menghambat pertumbuhan bakteri Erwinia sp.
English Abstract
Potatoes (Solanum tuberosum L.) is one of the reliable commodities in Indonesia, but there are obstacles in increasing potato tuber production. One of them is the attack of Erwinia sp. which causes soft rot in potato tubers. Control efforts can be made by utilizing biological control agents (APH) with rhizosphere bacteria. However, the use of APH has its drawbacks, one of which is the concentration of secondary metabolites produced by APH that cannot be predicted with certainty. This study aims to determine the potential of UB forest's rhizosphere biological agents and the potential use of secondary metabolites of rhizosphere bacteria in inhibiting the growth of Erwinia sp. causes of soft rot of potato tuber. The study was conducted in the laboratory of plant diseases 1 and toxicology of pesticides, Department of Plant Pests and Diseases, Faculty of Agriculture, University of Brawijaya, Malang from January to April 2019. The study consisted of several stages: (1) Rejuvenation of Erwinia sp. and UB forest Rhizosphere bacteria (2) Test of Pathogenicity (3) selection of UB forest rhizosphere bacterial antagonists to Erwinia sp. (4) test the antagonist of UB forest's rhizosphere bacteria against Erwinia sp. in vitro (5) type of antibiosis test (6) extraction of secondary metabolites of rhizosphere bacteria (7) inhibition test of secondary metabolites to Erwinia sp. in vitro (8) Test of suppression of soft rot on potato tubers by rhizosphere bacteria and secondary metabolites. The results of the selection of 34 isolates of UB forest rizosphere bacteria obtained 24 bacterial isolates that were antagonistic to the pathogen Erwinia sp. All rhizosphere bacterial isolates had an inhibitory index (IP) higher than the treatment of streptomycin sulfate even though bacterial isolates were bacteriostatic so that IP decreased in inhibiting Erwinia sp. Two bacterial isolates with the highest IP were Bacillus sp. Isolates. N3 and Pseudomonas sp. N19. Results of testing of secondary metabolites of Bacillus sp. N3 and Pseudomonas sp. N19 against Erwinia sp. in vitro showed lower IP compared to antagonistic testing using bacterial isolates. The presence of biomass isolates from Bacillus sp. N3 and Pseudomonas sp. The N19 can increase the production of secondary metabolites in inhibiting Erwinia sp. Whereas in suppressing soft rot disease on potato tubers, secondary metabolites of rhizosphere bacteria are more effective to use than using rhizosphere bacterial isolates. This is because bacterial isolates need time to produce secondary metabolites which can inhibit the growth of Erwinia sp.
| Item Type: | Thesis (Sarjana) |
|---|---|
| Identification Number: | SKR/FP/2019/488/051907262 |
| Uncontrolled Keywords: | - |
| Subjects: | 600 Technology (Applied sciences) > 635 Garden crops (Horticulture) > 635.2 Edible tubers and bulbs > 635.21 Potatoes |
| Divisions: | Fakultas Pertanian > Agroekoteknologi |
| Depositing User: | soegeng sugeng |
| Date Deposited: | 24 Aug 2020 07:01 |
| Last Modified: | 24 Aug 2020 07:01 |
| URI: | http://repository.ub.ac.id/id/eprint/173102 |
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