Respons Ketahanan Tembakau terhadap Tobamovirus dengan Agens Hayati sebagai Induser

Tobamovirus is one of the important pathogen that  decrease   the quantity and quality  of cigar tobacco cultivation. One of the alternative control of this disease is by using rhizosphere biological agents such as Bacillus spp., Streptomyces spp., and mycorrhiza. This study aims to determine the effectiveness and mechanism of the biological agents singly and in combination to induce cigar tobacco plant resistance of the F1 (TV38xG) variety in the greenhouse. The biological agents were applied on the root of tobacco during nursery and transplanting. The virus inoculation was performed 10 days after transplanting. The results showed that the treatment with Bacillus spp., Streptomyces spp., and mycorrhizal were capable to decrease disease incidence by delaying mosaic symptoms  for 6-day in a single treatment and 3 days in combination treatment. The treatment of Bacillus spp., Streptomyces spp., and mycorrhiza both in single and in combination were capable to decrease the disease intensity for 26%, 23%, 15%, and 10%, respectively. Induced resistance was performed by increased peroxidase activity in the treatment of mycorrhiza as much as 29.27%, Bacillus spp. 20.65%, and Streptomyces spp. 11.10%. Protein analysis with SDS-PAGE of tobacco plants  showed the difference in profile and size of protein bands. Protein bands measuring 17 kDa and 30 kDa were found in tobacco infected Tobamovirus but was not found in healthy tobacco. The single application of Bacillus spp., Streptomyces spp., and mycorrhiza on tobacco infected Tobamovirus  increase plant growth including plant height as much as 53.71%, number of leaves 57%, stem diameter 29.40%, root length 60.77%, fresh weight of leaves 196.90%, and dry weight of leaf of 265.31%.   Intisari Tobamovirus merupakan salah satu patogen penting yang menyebabkan penurunan kuantitas dan kualitas pada budidaya tembakau cerutu. Salah satu alternatif pengendalian penyakit ini menggunakan agens hayati pengkoloni akar yaitu Bacillus spp., Streptomyces spp., dan Mikoriza. Penelitian bertujuan untuk mengetahui efektivitas dan mekanisme agens hayati secara tunggal dan kombinasi dalam menginduksi ketahanan tanaman tembakau cerutu varietas F1 (TV38xG) di rumah kaca. Agens hayati diaplikasikan pada perakaran tembakau pada saat pembibitan dan pindah tanam. Inokulasi virus dilakukan 10 hari setelah pindah tanam. Hasil penelitian menunjukkan bahwa perlakuan Bacillus spp., Streptomyces spp., dan Mikoriza dapat menurunkan insidensi penyakit dengan menunda munculnya gejala mosaik 6 hari pada perlakuan tunggal dan 3 hari pada perlakuan kombinasi. Perlakuan Bacillus spp., Streptomyces spp., dan Mikoriza secara tunggal, dan kombinasi dapat menurunkan intensitas penyakit mosaik berturut-turut 26%, 23%, 15%, dan 10%. Induksi ketahanan terbentuk melalui peningkatan aktivitas peroksidase pada perlakuan Mikoriza 29,27%, Bacillus spp. 20,65%, Streptomyces spp. 11,10%. Analisis protein dengan SDS-PAGE diperoleh adanya perbedaan profi dan ukuran pita protein. Ditemukan pita protein berukuran 17 kDa dan 30 kDa pada tembakau yang terinfeksi Tobamovirus tetapi tidak ditemukan pada tembakau sehat. Aplikasi Bacillus spp., Streptomyces spp., dan Mikoriza secara tunggal pada tanaman tembakau yang terinfeksi Tobamovirus berpengaruh baik terhadap pertumbuhan tanaman. Tinggi tanaman meningkat 53,71%, jumlah daun 57%, diameter batang 29,40%, panjang akar 60,77%, berat segar daun 196,90%, dan berat kering daun 265,31%.