ABSTRAKLayu bakteri yang disebabkan oleh Ralstonia solanacearum merupakan salah satu penyakit penting pada tanaman nilam. Perakitan varietas nilam tahan terhadap penyakit tersebut yang dilakukan melalui induksi keragaman somaklonal telah menghasilkan beberapa somaklon yang tahan terhadap R. solanacearum secara in-vitro. Tujuan penelitian adalah menguji tingkat ketahanan somaklon tersebut terhadap penyakit layu pada kondisi rumah kaca (in-vivo). Penelitian disusun dalam Rancangan Acak Lengkap dengan 27 perlakuan, 3 ulangan, dan 10 tanaman/ulangan. Sebagian akar dari somaklon nilam dilukai (dipotong), selanjutnya diinokulasi (disiram) dengan suspensi R. solanacearum dengan berbagai konsentrasi 105, 107, dan 109 cfu/ml, sebanyak 50 ml/tanaman. Hasil penelitian menunjukkan, bahwa somaklon yang diinokulasi dengan konsentrasi 105 cfu/ml, 50 ml/tanaman semuanya tidak menunjukkan gejala layu. Somaklon yang diinokulasi dengan konsentrasi 107 dan 109cfu/ml, 50 ml/tanaman, sebagian layu dan mati. Dari somaklon yang7diinokulasi dengan konsentrasi 10 cfu/ml, 50 ml/tanaman, 8 di antaranyamenunjukkan respon sangat tahan, 4 tahan, dan 5 agak tahan. Ke 17 somaklon tersebut mempunyai intensitas penyakit <50% dan semua lebih tahan dari pada varietas Sidikalang (agak toleran). Dari 17 somaklon yang diinokulasi dengan konsentrasi 109 cfu/ml, 50 ml/tanaman, 2 di antaranya sangat tahan dan 7 somaklon tahan. Teknik skrining ini dapat digunakan sebagai metode standar untuk pengujian ketahanan nilam terhadap penyakit layu.Kata kunci: Skrining ketahanan, somaklon, nilam, penyakit layu, R. solanacearum. ABSTRACTResistance-Screening of Patchouli Somaclones on Bacterial Wilt Disease (Ralstonia solanacearum) Bacterial wilt caused by Ralstonia solanacearum is one of the most important diseases on patchouli. The developing patchouli resistance varieties against wilt disease conducted through the induction of somaclonal variation produced resistant patchouli somaclones against R. solanacearum (in-vitro). The aim of this research was to screen the resistance of those patchouli somaclones against wilt disease under a glass house condition (in-vivo). The research was conducted in a Randomized Completely Design with 27 treatments, 3 replicates, and 10 plants/ replicate. Some roots of the patchouli somaclones were wounded (cut), then inoculated (drenched) with R. solanacearum suspension in concentration of 105, 107, and 109 cfu/ml; 50 ml/plant. The result showed, that all the patchouli somaclones inoculated with R. solanacearum 105 cfu/ml, 50 ml/plant were not show any wilt sympthom. Whereas, some somaclones inoculated with the higher concentration 107 and 109 cfu/ml, 50 ml/plant were wilted and died. Among the somaclones inoculated with the concentration of 107 cfu/ml, 50 ml/plant, 8 of them were highly resistant, 4 were resistant, and 5 were moderately resistant. The disease intencity of those 17 somaclones were <50% and they were more resistant than the Sidikalang variety (moderately tolerant). Among those 17 somaclones inoculated with the concentration of 109 cfu/ml, 50 ml/plant, 2 of them were highly resistant and 7 were resistant. This screening method could be used as a standard protocol for patchouli resistance screening against wilt disease.Kata kunci: Screening resistance, somaclone, patchouli, wilt disease, R. solanacearum.