PERLAKUAN POLYETHYLENE GLYCOL SECARA IN VITRO TERHADAP PERTUMBUHAN TUNAS MUTAN TAKA UNTUK SELEKSI TOLERAN KEKERINGAN

Abstract

Tacca leontopetaloides (L.) Kuntze merupakan salah satu tanaman umbi-umbian yang berpotensi untuk pangan alternatif. Induksi mutasi antara lain dengan radiasi sinar Gamma merupakan salah satu upaya untuk perbaikan genetik tanaman. Pada taka telah diperoleh kandidat mutan yang perlu diseleksi untuk mendapatkan genotipe toleran kekeringan. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh pemberian PEG secara in vitro terhadap pertumbuhan mutan tunas taka hasil radiasi sinar Gamma untuk seleksi toleran kekeringan. Penelitian menggunakan 3 klon mutan taka hasil radiasi dosis 20, 30, dan 40 Gy dan tunas tanpa radiasi (kontrol). Semua tunas ditanam pada media MS dengan penambahan 0; 2.5; 5; 7.5; dan 10% PEG dengan 3 ulangan. Parameter yang diamati adalah tinggi tanaman, jumlah daun dan jumlah akar, diamati setiap minggu hingga minggu ke-8. Data dianalisis dengan analisis variansi (ANOVA) dilanjutkan dengan Uji DMRT (Duncan Multiple Range Test). Penelitian dilaksanakan di Laboratorium Biak Sel dan Jaringan Tanaman  Pusat Penelitian Bioteknologi LIPI selama 4 bulan. Hasil penelitian menunjukkan bahwa tunas tertinggi diperoleh dari klon 40 Gy tanpa penambahan PEG sebesar 4.83 cm. Semakin tinggi konsentrasi PEG, tinggi tanaman semakin rendah. Jumlah daun dan jumlah akar tertinggi diperoleh dari tunas 20 Gy tanpa penambahan PEG yaitu sebesar 5.89 helai daun dan 2 helai akar. Tidak semua planlet hasil perlakuan PEG berhasil diaklimatisasi, daya hidup tertinggi didapatkan dari planlet tanpa radiasi dengan penambahan PEG 2.5% dan planlet taka hasil radiasi 20 Gy dengan penambahan PEG 7.5% sebesar 100%.

ABSTRACT

Tacca leontopetaloides (L.) Kuntze is tuberous plant that has potential for alternative food source. Mutant induction by Gamma ray irradiation is useful for plant genetic improvement. Mutant candidate of Tacca has been obtained from the previous research and was selected for drought tolerant. The aim of the research was to investigate the effect of PEG as drought stress inducer on in vitro growth of Tacca mutant for selecting drought tolerant clones. The research was used 3 clones of mutant obtained from Gamma irradiation at 20, 30 and 40 Gy as well as without irradiation (control). All shoots were grown on MS medium containing 0; 2.5; 5; 7.5; and 10% PEG with            3 replicates. The Observed parameters were height of shoots, number of leaves and number of roots. The data were recorded every week from week-1 to week-8. Data were analized using ANOVA followed by Duncan Multiple Range Test (DMRT). The research was conducted in Plant Cell and Tissue Culture Laboratory, Research Center of Biotechnology – Indonesian Institute of Sciences for 4 months. The results indicated that the highest shoots were obtained from 40 Gy clones, cultured on MS medium without PEG (4.83 cm). The higher PEG concentrations gave the lower height of shoots. The highest of leaf numbers and roots numbers were found on 20 Gy mutant grown on MS medium without PEG addition (5.89 leaves and 2 roots, respectively). After PEG treatments, some plantlets did not survive after acclimation. The highest survival rate was found from non-irradiated plantlets grown on MS medium containing 2.5% PEG and from 20 Gy-mutant  grown on MS medium containing 7.5% PEG, respectively which gave 100% survival rate.