Abstrak. Tujuan penelitian ini adalah untuk mengetahui performansi beberapa galur mutan cabai generasi M3 pada berbagai tingkat cekaman salinitas pada viabilitas dan vigor benih serta vegetatif tanaman, dan interaksi antara kedua faktor. Penelitian ini dilaksanakan di Laboratorium Ilmu dan Teknologi Benih dan Rumah Kasa Fakultas Pertanian Universitas Syiah Kuala Banda Aceh pada bulan Juni sampai Agustus 2021. Percobaan ini disusun menggunakan rancangan acak lengkap pola faktorial yang terdiri atas 2 faktor dan 3 ulangan. Faktor pertama adalah galur mutan cabai lokal generasi M3 yang terdiri dari 5 taraf yaitu sebagai kontrol digunakan varietas Odeng dan galur M3 O10 D1-5, M3 O7 D2-39, M3 O9 D3-9, M3 O9 D3-34. Faktor kedua adalah konsentrasi NaCl pada media tanam yang terdiri dari 4 taraf yaitu 0 ppm, 5000 ppm, 7.500 ppm, 10.000 ppm. Hasil penelitian menunjukkan bahwa setiap galur mutan memiliki respon yang berbeda terhadap salinitas. Konsentrasi NaCl 7,81ds/m (K1), galur sudah mulai menunjukkan penurunan nilai viabilitas dan vigor benih serta pertumbuhan vegetatif tanaman. Viabilitas dan vigor tertinggi terdapat pada perlakuan varietas Odeng yang kemudian diikuti oleh mutan M3 O9 D3-9, mutan M3 O10 D1-5, mutan M3 O7 D2-39 dan terendah pada mutan M3 O9 D3-34. Varietas odeng, dan mutan M3 O9 D3-9 memiliki daya berkecambah yang lebih baik pada cekaman salinitas dibandingkan dengan galur mutan lainnya.Response of Viability and Vigor of Seed and Vegetative Growth of M3 Generation of Odeng Variety to Several Levels of Salinity StressAbstract. The purpose of this study was to determine the performance of several M3 generation chili mutant lines at various levels of salinity stress on seed viability and vigor as well as plant vegetativeness, and the interaction between the two factors. This research was conducted at the Laboratory of Seed Science and Technology and Screening House, Faculty of Agriculture, Syiah Kuala University, Banda Aceh from June to August 2021. This experiment was arranged using a completely randomized design with a factorial pattern consisting of 2 factors and 3 replications. The first factor was the M3 generation local chili mutant line which consisted of 5 levels, namely the Odeng variety as control and the M3 O10 D1-5, M3 O7 D2-39, M3 O9 D3-9, M3 O9 D3-34 varieties. The second factor is the concentration of NaCl in the growing media which consists of 4 levels, namely 0 ppm, 5000 ppm, 7,500 ppm, 10,000 ppm. The results showed that each mutant line had a different response to salinity. The NaCl concentration was 7.81ds/m (K1), the line had started to show a decrease in the viability and vigor values of the seeds as well as the vegetative growth of plants. The highest viability and vigor were found in the treatment of the Odeng variety, followed by the M3 O9 D3-9 mutant, the M3 O10 D1-5 mutant, the M3 O7 D2-39 mutant and the lowest was the M3 O9 D3-34 mutant. The odeng variety, and the M3 O9 D3-9 mutant had better germination rates under salinity stress than other mutant lines.