POTENSI PERMUDAAN ALAM DAN KERAGAMAN GENETIK CENDANA (Santalum album Linn.) DI DESA SEMUGIH KECAMATAN RONGKOP KABUPATEN GUNUNGKIDUL

SITI FADHURROHMAH, Dr. Sapto Indrioko, S.Hut., M.P.

2016 | Skripsi | S1 KEHUTANAN

Santalum album Linn. yang disebut cendana merupakan salah satu jenis komersial yang diperdagangkan dalam satuan kilogram. Saat ini, populasi cendana mengalami penurunan yang berdampak pada penurunan keragaman genetik dihabitat aslinya. Telah diketahui bahwa cendana tumbuh di Gunungkidul dan beberapa penelitian keragaman genetik telah dilakukan. Desa Semugih merupakan wilayah terakhir di Gunungkidul yang miliki karakter berbeda dengan populasi lain karena kegiatan pencarian pakan ternak saat musim kemarau di bukit. Dengan demikian, perlu dilakukan penelitian untuk mengetahui potensi dan keragaman genetik guna melengkapi basis data keragaman genetik di Gunungkidul. Penelitian dibagi dalam empat tahap. Tahap pertama yaitu inventarisasi berdasarkan fase hidup cendana menggunakan petak ukur (10m x 10m) yang diletakkan secara purposive. Tahap kedua yaitu pengambilan sampel daun untuk analisis isozim. Tahap ketiga yaitu analisis keragaman genetik berdasarkan penanda isozim. Tahap keempat yaitu perhitungan potensi permudaan alam dan parameter keragaman genetik. Cendana tumbuh mengelompok atau menyebar pada 12 bukit di Desa Semugih. Kerapatan cendana didominasi oleh fase reproduktif, sementara fase semai dari permudaan generatif paling rendah kerapatannya. Permudaan alam lebih banyak berasal dari trubusan akar akibat adanya pencarian pakan ternak di bukit. Potensi reproduksi paling rendah (1%) dibandingkan populasi lainnya. Keragaman genetik di Desa Semugih menurun dari generasi ke generasi. Rata-rata heterozigositas observasi (HO) yaitu 0,200 dan heterozigositas harapan (HE) yaitu 0,285 sebagai hasil sistem perkawinan kerabat (FIS = 0,231). Perkawinan kerabat terjadi karena melimpahnya individu hasil permudaan vegetatif. Alel yang hilang teramati di lokus Est-2, sementara alel langka ditemukan pada lokus Est-1, Est-3, dan Dia-2. Hal ini diduga akibat founder effect serta adanya proses genetic drift.

Santalum album Linn. known as sandalwood, is one of the commercial species and traded in kilograms. Currently, there is a decrease in the population of sandalwood, which impacts on the genetic diversity of their natural habitat. It is known that sandalwood grows in Gunungkidul and some genetic diversity studies have been conducted. Semugih village is the last area in Gunungkidul that has a different character in comparison to the other populations because fodder collecting activities are conducted during dry seasons in hills. Thus, it is necessary to investigate the natural regeneration potential and genetic diversity in order to complete the database of genetic diversity in Gunungkidul. This research consists of four stages. The first stage was the inventory of sandalwood based on their phases of life using purposive sampling plot (10mx10m). The second stage was the sampling of leaves for isozyme analysis. The third stage was the analysis of genetic diversity based on isozyme markers. Lastly, the fourth stage was to calculate the natural regeneration potential and genetic diversity parameters. Sandalwood grows in a group or scattered on 12 hills in Semugih village. The density of sandalwood is dominated by reproductive phase, while the seedling phase has the lowest density. Natural regeneration is mostly derived from root suckers as an impact of fodder collecting in the hills. The reproductive potential is the lowest (1%) in comparison to the other populations. The genetic diversity in Semugih village decline from generation to generation. The average value of the observed heterozygosity (HO) is 0,200 and expected heterozygosity (HE) is 0,285 resulted from inbreeding mating system (FIS = 0,231). The inbreeds are influenced by vegetative propagation. Missing allele is observed on Est-2 loci, while are rare alleles are found on Est-1, Est-3, and Dia-2 loci. This might have been caused by founder effect and genetic drift process.

Kata Kunci : cendana, isozim, potensi permudaan alam, kerapatan, potensi reproduksi, keragaman genetik, Desa Semugih.