KERAGAMAN GENETIKA VARIAN ABAKA YANG DIINDUKSI DENGAN ETHYLMETHANE SULPHONATE (EMS)

ABSTRAK Mutasi in vitro dengan perlakuan mutagen dapat digunakan untuk meningkatkan keragaman genetika abaka melalui keragaman somaklonal. Penelitian yang dilakukan bertujuan untuk: (1) menentukan konsentrasi optimum EMS untuk induksi keragaman somaklonal dalam kultur kalus embriogen abaka, (2) meregenerasikan bibit abaka varian dari kalus embriogen yang diberi perlakuan EMS, dan (3) mengevaluasi tipe dan frekuensi keragaman karakter kualitatif dan kuantitatif di antara populasi tanaman mutan abaka yang diperoleh dari regenerasi kalus embriogen yang diberi perlakuan EMS. Penelitian dilakukan mulai bulan Agustus 2003 sampai Agustus 2006 di Laboratorium Kultur Jaringan dan Kebun Percobaan Karangploso, Malang pada Balai Penelitian Tanaman Tembakau dan Serat, Malang (Balittas). Hasil penelitian menunjukkan bahwa 0,6% EMS merupakan konsentrasi optimum karena pada konsentrasi tersebut diperoleh keragaman somaklonal paling banyak. Varian yang diperoleh menunjukkan karakter kualitatif dan kuantitatif abnormal. Tipe varian tersebut umumnya bersifat negatif dan kurang menguntungkan dibandingkan dengan populasi standar. Tipe dan frekuensi keragaman kualitatif dan kuantitatif pada klon Tangongon berbeda dengan klon Sangihe-1, mengindikasikan adanya pengaruh genotipe terhadap keragaman somaklonal. Varian dari abaka klon Tangongon dengan produksi serat tertinggi (161,0 g dan 154,0 g/tanaman) diperoleh dari perlakuan EMS 0,3% (T1 28.1.1 dan T1 11.2.2), sedangkan dari klon Sangihe-1, hasil serat tertinggi (35,0 g dan 40,0 g/tanaman) diperoleh dari perlakuan EMS 0,6% (S4 28.1.0 dan S4 56.2.0). Produktivitas tersebut lebih rendah dibandingkan dengan produksi serat tanaman kontrol klon Tangongon (193,0 g/tanaman) dan Sangihe-1 (70 g/tanaman). Kata kunci : Abaka, Musa textilis, keragaman somaklonal, EMS, muta- genesis, in vitro, hasil, Jawa Timur ABSTRACT Genetic Variability of Abaca Variants Induced by Ethylmethane Sulphonate (EMS) In vitro mutation with mutagen treatment can be used to increase the genetic variability of abaca by inducing somaclonal variation. The objectives of the experiments were to (1) determine optimum concen- tration of EMS to induce abaca somaclonal variation, (2) produce abaca lines from EMS treated embryogenic calli and evaluate their performance in the field, and (3) evaluate type and frequency of qualitative and quantitative variant characters among regenerated abaca lines. This experiment was conducted in Tissue Culture Laboratory and Karangploso Experiment Station of Indonesian Tobacco and Fibre Crops Research Institute (ItoFCRI) Malang from August 2003 to August 2006. The results showed that EMS treatment on abaca embryogenic calli induced variation, and the optimum EMS concentration was 0.6%. The variants exhibited a number of abnormal qualitative and quantitative characters which were generally negative characters since they showed lower value as compared to control population. The presence of different types of qualitative and quantitative variant characters was genotype dependent. Variants from abaca clone Tangongon having the highest fibre yield (161.0 g and 154.0 g/plant) were obtained from 0.3% EMS treatment (T1 28.1.1 and T1 11.2.2 variants). While variants from abaca clone Sangihe-1 having the highest fibre yield (35.0 g and 40.0 g/plant) were obtained from 0.6% EMS treatment (S4 28.1.0 and S4 56.2.0 variants). The fibre yield of control clones, Tangongon and Sangihe-1, were 193.0 g and 70 g/plant, respectively. Key words: Abaca, Musa textilis, induced mutation, somaclonal variation, field evaluation, yield, East Java