PENGUJIAN PENANDA RANDOM AMPLIFIED POLYMORPHISM DNA UNTUK MENGETAHUI KESTABILAN GENETIK KLON JATI (Tectona grandis)

Abstract

This study aimed to test RAPD markers to assess genetic stability of teak clones. Two experimental steps were carried out. First, nine RAPD markers were screened to verify the level of polymorphic loci using non clone samples; second, the polymorphic loci were applied to test genetic stability of clones from tissue culture. To test polymorphism levels of the primers, DNA was isolated from eight leaf samples that were collected from a seed orchard located at Watusipat, Gunung Kidul. To verify genetic stability of clones, DNA was isolated from leaf samples of 24 ramets of 3 clones after second sub-culturing. Results showed that amplification of 5 out of 9 RAPD primers were consistent and produced 12 polymorphic loci. The number of polymorphic alleles per locus ranged between 1 and 3; the allele sizes were between 400 and 1050 base pairs (bps). The percentage of polymorphic loci was 100%; it meant that overall loci have high polymorphism level. Based on these loci showed that the 24 ramets are clones; there was no somaclonal variation or high genetic stability. However, these loci need to be validated using more stable DNA markers. ABSTRAKPenelitian ini bertujuan untuk menguji penanda RAPD pada kestabilan genetik klon jati. Pengujian ini melalui dua tahap penelitian yaitu memilih penanda RAPD yang mengamplifikasikan lokus polimorfik pada sampel bukan klon, kemudian target lokus polimorfik tersebut diujikan pada sampel klon hasil kultur jaringan. Sampel DNA bukan klon berasal dari kebun benih jati di Watusipat, Gunung Kidul. Sampel DNA klon berasal dari 24 ramet, dari 3 klon setelah 2 kali sub kultur. Hasil penelitian menunjukkan bahwa 5 dari 9 penanda RAPD pada sampel bukan klon, bersifat konsisten dan menghasilkan 12 lokus polimorfik. Jumlah alel polimorfik per lokus berkisar antara 1 sampai dengan 3; ukuran alel berkisar antara 400 sampai 1050 pasangan basa (bp). Persentase lokus polimorfik bernilai 100% menunjukkan bahwa seluruh lokus mempunyai nilai polymorphism tinggi. Berdasarkan 12 lokus tersebut, 24 ramet menunjukkan genotipe yang sama pada masing-masing klonnya. Namun demikian, target lokus tersebut masih harus divalidasi menggunakan penanda DNA yang sifatnya lebih stabil. Kata kunci: kultur jaringan, pemilihan primer, lokus polimorfik, variasi somaklonal