<p>ABSTRAK</p><p>Layu bakteri yang disebabkan oleh <em> Ralstonia solanacearum <br /> </em>merupakan salah satu penyakit penting pada tanaman nilam. Perakitan <br /> varietas nilam tahan terhadap penyakit tersebut yang dilakukan melalui <br /> induksi keragaman somaklonal telah menghasilkan beberapa somaklon <br /> yang tahan terhadap <em>R. solanacearum</em> secara <em>in-vitro</em>. Tujuan penelitian <br /> adalah menguji tingkat ketahanan somaklon tersebut terhadap penyakit <br /> layu pada kondisi rumah kaca (<em>in-vivo</em>). Penelitian disusun dalam <br /> Rancangan Acak Lengkap dengan 27 perlakuan, 3 ulangan, dan 10 <br /> tanaman/ulangan. Sebagian akar dari somaklon nilam dilukai (dipotong), <br /> selanjutnya diinokulasi (disiram) dengan suspensi<em> R. solanacearum</em> dengan <br /> berbagai konsentrasi 10<sup>5</sup>, 10<sup>7</sup>, dan 10<sup>9 </sup><em>cfu</em>/ml, sebanyak 50 ml/tanaman. <br /> Hasil penelitian menunjukkan, bahwa somaklon yang diinokulasi dengan <br /> konsentrasi 10<sup>5 </sup><em>cfu</em>/ml, 50 ml/tanaman semuanya tidak menunjukkan <br /> gejala layu. Somaklon yang diinokulasi dengan konsentrasi 107 dan 10<sup>9</sup></p><p><em>cfu</em>/ml, 50 ml/tanaman, sebagian layu dan mati. Dari somaklon yang</p><p>7</p><p>diinokulasi dengan konsentrasi 10 <em>cfu</em>/ml, 50 ml/tanaman, 8 di antaranya</p><p>menunjukkan respon sangat tahan, 4 tahan, dan 5 agak tahan. Ke 17 <br /> somaklon tersebut mempunyai intensitas penyakit <50% dan semua lebih <br /> tahan dari pada varietas Sidikalang (agak toleran). Dari 17 somaklon yang <br /> diinokulasi dengan konsentrasi 10<sup>9 </sup><em>cfu</em>/ml, 50 ml/tanaman, 2 di antaranya <br /> sangat tahan dan 7 somaklon tahan. Teknik skrining ini dapat digunakan <br /> sebagai metode standar untuk pengujian ketahanan nilam terhadap <br /> penyakit layu.</p><p>Kata kunci: Skrining ketahanan, somaklon, nilam, penyakit layu,<em> R. solanacearum.</em></p><p><em> </em></p><p><em></em>ABSTRACT</p><p>Resistance-Screening of Patchouli Somaclones on Bacterial Wilt Disease (Ralstonia solanacearum) </p><p>Bacterial wilt caused by <em>Ralstonia solanacearum </em>is one of the most <br /> important diseases on patchouli. The developing patchouli resistance <br /> varieties against wilt disease conducted through the induction of <br /> somaclonal variation produced resistant patchouli somaclones against <em>R. <br /> </em><em>solanacearum </em>(in-vitro). The aim of this research was to screen the <br /> resistance of those patchouli somaclones against wilt disease under a glass <br /> house condition (in-vivo). The research was conducted in a Randomized <br /> Completely Design with 27 treatments, 3 replicates, and 10 plants/ <br /> replicate. Some roots of the patchouli somaclones were wounded (cut), <br /> then inoculated (drenched) with <em> R. solanacearum</em> suspension in <br /> concentration of 10<sup>5</sup>, 10<sup>7</sup>, and 10<sup>9 </sup><em>cfu</em>/ml; 50 ml/plant. The result showed, <br /> that all the patchouli somaclones inoculated with <em>R. solanacearum</em> 10<sup>5 <br /> </sup>cfu/ml, 50 ml/plant were not show any wilt sympthom. Whereas, some <br /> somaclones inoculated with the higher concentration 10<sup>7 </sup>and 109 cfu/ml, 50 ml/plant were wilted and died. Among the somaclones inoculated with the concentration of 10<sup>7</sup> 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 <br /> somaclones inoculated with the concentration of 10<sup>9 </sup>cfu/ml, 50 ml/plant, 2 <br /> of them were highly resistant and 7 were resistant. This screening method <br /> could be used as a standard protocol for patchouli resistance screening <br /> against wilt disease.</p><p>Kata kunci: Screening resistance, somaclone, patchouli, wilt disease, <em>R. solanacearum.</em></p>