VARIASI GENETIK PERMUDAAN CENDANA (Santalum album Linn.) PADA BEBERAPA FISIOGNOMI DI WANAGAMA I MENGGUNAKAN PENANDA ISOENZIM

YULIAH, Dr. Sapto Indrioko, S.Hut, MP.

2011 | Tesis | S2 Ilmu Kehutanan

Cendana (Santalum album Linn) merupakan salah satu tumbuhan asli Indonesia yang termasuk ke dalam daftar jenis yang rentan terhadap kepunahan. Upaya penanaman cendana telah dilakukan oleh banyak pihak, termasuk yang dilakukan oleh Fakultas Kehutanan Universitas Gadjah Mada di Wanagama I, sejak tahun 1968. Saat ini permudaan alam cendana telah tersebar ke hampir semua Petak di Wanagama I. Berdasarkan dominasi vegetasi penyusunnya, Wanagama I dapat dibedakan menjadi fisiognomi I (Petak 7), fisiognomi II (Petak 16) dan fisiognomi III (Petak 5). Perbedaan kondisi di masing masing fisiognomi disinyalir memengaruhi populasi cendana, baik dari segi jumlah maupun variasi genetiknya. Tujuan penelitian ini adalah untuk: 1) Mengetahui variasi genetik populasi permudaan cendana pada berbagai fisiognomi di Wanagama I, Yogyakarta, 2) Mengetahui perubahan variasi genetik populasi permudaan cendana pada berbagai tingkatan hidup di Wanagama I, serta 3) Merekomendasikan strategi konservasi cendana berdasarkan informasi genetiknya. Kegiatan penelitian dilakukan di lapangan dan di laboratorium. Pengambilan sampel di lakukan di 3 petak yang dipilih secara purposive berdasarkan fisiognominya. Kemudian dilakukan survei pendahuluan untuk melihat potensi permudaan cendana, selanjutnya dibuat transek dengan awal random. Pada setiap transek dibuat Petak ukur 20 x 20 m. Pada setiap plot, daun muda cendana pada berbagai tahapan hidup diambil sebagai sampel materi genetik. Analisis isoenzim dilakukan di laboratorium menggunakan sistem enzim EST (Esterase), DIA (Diaphorase) dan SHD (Shikimate Dehydrogenase). Teridentifikasi 5 lokus polimorfik dengan jumlah total alel sebanyak 12. Ratarata alel per lokus pada ketiga fisiognomi adalah 2,47. Rata-rata alel efektif per lokus sebesar 1,6223. Rata-rata nilai heterozigositas harapan pada semua fisiognomi adalah 0,3333. Nilai heterozigositas harapan terendah dijumpai pada tingkatan hidup pohon di fisiognomi III (HE= 0,2444), dan tertinggi pada tingkatan hidup semai di fisiognomi I (HE= 0,3894). Rerata indeks fiksasi adalah -0,0366. Indeks fiksasi bernilai positif terbesar dijumpai pada tingkat pohon di fisiognomi III (0,4545), sedangkan indeks fiksasi bernilai negatif terbesar dijumpai pada sapihan, fisiognomi I (-0,2329). Strategi konservasi cendana berdasarkan informasi variasi genetiknya diarahkan untuk memfasilitasi alel-alel langka agar tidak punah, menambah ukuran populasi, melakukan manajemen agen penyerbuk, serta menjaga kelestarian burungburung yang berperan dalam persebaran biji cendana. Pendekatan pada masyarakat juga perlu dilakukan agar ikut aktif menjaga kelestarian cendana.

Sandalwood (Santalum album Linn) is one of Indonesian original species, categorized as vulnerable tree species to extinct. Efforts has been established since 1968 to cultivate sandalwood by developing ex-situ conservation, including in Wanagama I Education Forest, Gunung Kidul. Currently, its natural regeneration spreadly occurs almost in all compartments in Wanagama I. Based on the dominant vegetation composition, Wanagama I could be classified into physiognomy I (compartment 7), physiognomy II (compartment 16) dan physiognomy III (compartment 5). The aims of this research weree: 1) to know population genetic variation of sandalwood regeneration on 3 different physiognomies, 2) to recognize the changes of population genetic variation in different regeneration stages, and 3) to develop conservation strategy of sandalwood based on its genetic information. This research combined field and laboratory activities. Field activity has been conducted in three compartments at Wanagama I Gunung Kidul that were selected purposively based on their physiognomy status. Survey has been conducted to investigate the sandalwood natural regeneration in those compartments using transects and observational plots with size of 20 x 20 m. In each plot, young sandalwood leaves in different regeneration stages were taken as samples of genetic materials. They were analyzed in the laboratory using isoenzymes. Enzyme systems used were EST (Esterase), DIA (Diaphorase) and SHD (Shikimate Dehydrogenase). The research results showed that there were 5 polymorphics loci and 12 alleles in all sample compartments. The average number of allele per locus for all physiognomy was 2,47. The average number of effective alleles per locus was 1.6223. Moreover, the average number of expected heterozygosity in all physiognomy was 0,333. The tree stage of physiognomy III showed the lowest expected heterozygosity (HE= 0,2444), while the highest one was found in the seedling stage of physiognomy I (HE= 0,3894). Beside, the average number of fixation index is -0,0366. The highest positive number of fixation index was found in the tree stage of physiognomy III (0,4545), while the highest negative number of fixation index was found in the sapling stage of physiognomy I (-0,2329). This research also suggests formulating sandalwood conservation strategy based on genetic variation information by facilitating rare alleles in order to prevent extinction, enlarging population size, managing pollinator agencies, and maintaining the existence of certain birds which is helpful for spreading sandalwood seed. Approaching to local community was also an important genetic conservation effort especially to actively participate in planting and maintaining the sandalwood species.

Kata Kunci : Cendana, isoenzim, konservasi sumberdaya genetik, Wanagama I