ABSTRACT Inoculation Techniques of Clavibacter michiganensis subsp. sepedonicus, the Cause of Bacterial Ring Rot Disease, on Potato (Solanum tuberosum L.). Clavibacter michiganensis subsp. sepedonicus, the cause of bacterial ring rot disease on potatoes, has been detected in potato fields in Pangalengan. To anticipate the spread of the pathogen, researches on the desease epidemiology are urgent to be carried out. Artificial inoculation techniques will be useful in the epidemiological studies. The objective of this reasearch was to evaluate some inoculation techniques, which are simple, cheap and fast in causing disease symptoms. The experiment was carried out at the laboratory and glasshouse of Balai Penelitian Tanaman Sayuran (Balitsa), Lembang. The experiment was arranged in the randomized block design with five treatments of inoculation technique and five replications. The treatments were (a) soaking wounded seed tubers in pathogen suspension, (b) soaking not wounded seed tubers in pathogen suspension, (c) pathogen suspension was injected into leaf axil, (d) pathogen suspension was injected into seed tubers, and (e) pathogen suspension was poured into the planting holes. The results showed that stabbing and soaking tubers in pathogen suspension caused the shortest incubation period (17 days after inoculation) and the highest disease incidence (60%). Keywords : Clavibacter michiganensis subsp. sepedonicus, Bacterial ring rot, Potatoes, Inoculation techniquesABSTRAKClavibacter michiganensis subsp. sepedonicus (Cms), penyebab penyakit busuk cincin bakteri pada tanaman kentang, telah terdeteksi keberadaannya pada pertanaman kentang di Pangalengan. Dalam upaya mencegah penyebaran penyakit busuk cincin bakteri di Indonesia, perlu adanya studi epidemiologi patogen tersebut. Pada penelitian epidemiologi akan diperlukan cara menginokulasi tanaman secara buatan. Tujuan dari penelitian ini adalah untuk mendapatkan teknik inokulasi buatan yang dapat menyebabkan periode inkubasi yang lebih singkat dan persentase kejadian penyakit busuk cincin bakteri paling tinggi pada tanaman kentang. Percobaan dilaksanakan di rumah kaca dan laboratorium penyakit Balai Penelitian Tanaman Sayuran (Balitsa), Lembang. Percobaan dirancang secara rancangan acak kelompok dengan lima perlakuan teknik inokulasi Cms dan lima ulangan, yaitu inokulasi dengan (a) merendam ubi benih yang telah dilukai dalam suspensi bakteri, (b) merendam ubi benih tanpa dilukai dalam suspensi bakteri, (c) suspensi bakteri ditusukkan pada ketiak daun tanaman kentang, (d) suspensi bakteri ditusukkan pada ubi benih, dan (e) suspensi bakteri disiramkan pada lubang tanam. Masing-masing ulangan terdiri dari lima tanaman. Hasil penelitian menunjukkan bahwa dari lima teknik inokulasi buatan yang dilakukan, inokulasi dengan melukai ubi benih dan merendamnya dalam suspensi patogen menghasilkanJurnal Agrikultura 2016, 27 (2): 66-71ISSN 0853-2885Teknik Inokulasi Buatan Clavibacter….67periode inkubasi tersingkat, yaitu 17 hari setelah inokulasi, dan persentase kejadian penyakit tertinggi yaitu sebesar 60%.Kata Kunci : Clavibacter michiganensis subsp. sepedonicus, Busuk cincin bakteri, Kentang, Inokulasi buatan
The Putative Secreted Serine Protease Chp-7 Is Required for Full Virulence and Induction of a Nonhost Hypersensitive Response by Clavibacter michiganensis subsp. sepedonicus
