PROGRAM PEMULIAAN JELUTUNG RAWA (Dyera lowii Hook.f.) DI KALIMANTAN TENGAH
TRI SUWARNI WAHYUDININGSIH, Prof. Dr. Ir. Mohammad Na’iem, M.Agr. Sc.; Prof. Dr. Issirep Sumardi; Dr. Sapto Indrioko, S. Hut., MP.
2015 | Tesis | S3 Ilmu KehutananD. lowii adalah pohon endemik dan vulnerable di hutan rawa gambut yang berfungsi ekologis dan bernilai ekonomi. Penelitian ini bertujuan menganalisis keragaman genetik D. lowii dalam dan antar populasi serta hubungannya dengan sebaran di Kalimantan Tengah, menaksir tingkat outcrossing dan inbreeding, serta mengkaji macam eksplan dan zat pengatur tumbuh untuk induksi embrio somatik. Penelitian meliputi: I. Keragaman genetik, II. Sistem perkawinan, III. Embriogenesis somatik. Sampel penelitian diambil di 4 hutan alam rawa gambut (Hampangen, Parahangan, Sebangau, Selat Nusa) dan hutan tanaman Cilik Riwut. Analisis isozim dilakukan di Laboratorium Pemuliaan Fakultas Kehutanan UGM dan mikropropagasi dilakukan di Laboratorium Bioteknologi Fakultas Biologi UGM. Pelaksanaan penelitian: November 2011-November 2013. Eksplorasi materi daun muda dari 55 pohon per populasi sehingga terdapat 275 pohon untuk sampel penelitian I. Penelitian II digunakan sampel daun (224 semai) yang berasal dari 10 induk pohon. Eksplan penelitian III: biji dan semai (internodus, daun urutan pertama). Medium kultur: MS (Murashige &Skoog), NAA, IBA, BA, dan Kinetin. Analisis data penelitian I digunakan program POPGENE 1.3.1, penelitian II dengan program MLTR, dan penelitian III dengan analisis deskriptif. Heterozigositas harapan (HE) antara 0,422 (Hampangen) sampai 0,596 (Parahangan). Keragaman genetik terlengkap di populasi hutan alam rawa gambut Selat Nusa karena mempunyai private allele (Got-1-e). Diferensiasi genetik antar populasi (FST = 0,068) termasuk tingkat sedang (intermediet) dan estimasi aliran gen (Nm) = 3,402. Populasi Hampangen dan Parahangan membentuk satu klaster. Populasi hutan alam rawa gambut Sebangau dan Selat Nusa serta hutan tanaman membentuk satu klaster. Jarak geografis mencerminkan jarak genetiknya. D. lowii mempunyai nilai outcrossing yang tinggi (tm=80,1%) dan inbreeding rendah (tm-ts = 12,9%), sehingga keragaman genetik D. lowii masih tinggi. Eksplan daun pertama bagian pangkal dan tengah yang dikulturkan pada medium MS + BA 0,2 mg/l + IBA 0,5 mg/l menghasilkan embrio somatik. Sel-sel kalus embriogenik membentuk pro-embrio stadium: 2 sel, 4 sel, bulat, globuler dan terpedo. Berdasar keragaman genetik maka pengambilan sampling cukup mengambil satu populasi hutan alam rawa gambut Selat Nusa. Eksplorasi pohon plus D. lowii (kriteria: umur pohon, diameter batang, volume getah: karakter kulit batang, metode dan kondisi lingkungan penyadapan, dan fisiologi sel getah) perlu diterapkan untuk membangun populasi pemuliaan. Perbanyakan pohon plus dapat dilakukan dengan mengaplikasikan metode embriogenesis somatik
D. lowii is an endemic and vulnerable tree of peat-swamp forest with high ecology and economic values. The study was aimed to analyze genetic diversity of D. lowii, within and among populations, their correlation with distribution in Central Kalimantan, to assess the level of outcrossing and inbreeding, and to examine explants and growth regulators for somatic embryos inductions. The study included: I. Genetic diversity, II. Breeding system, III. Somatic embryogenesis. Samples were collected from four peat-swamp forests (Hampangen, Parahangan, Sebangau, Selat Nusa) and Cilik Riwut plantation. Isozyme analysis was conducted in the Laboratory of Tree Breeding Faculty of Forestry UGM and micro-propagation was done in the Laboratory of Biotechnology Faculty of Biology UGM. The study was carried out in November 2011—November 2013. The first study involved exploration of young-leaf materials of 55 trees per population, with total 275 trees as samples. Moreover, the second study used leaf samples of 224 seedlings derived from 10 parent trees. The third study used explants: seeds and seedlings (internodes, first-order leaf). Culture medium: MS (Murashige &Skoog), NAA, IBA, BA, and Kinetin. For the analysis, the first study applied POPGENE 1.3.1, the second study applied MLTR program, while the third study was descriptive analysis. Expected heterozygosity (HE) of 0.422 (Hampangen) to 0.596 (Parahangan). The highest genetic diversity was found in the population of Selat Nusa allegedly from its private allele (Got-1-e). Genetic differentiation among populations (FST = 0.068) can be categorized as intermediate with estimation of gene flow (Nm) = 3.402. Populations of Hampangen and Parahangan form a cluster, meanwhile, populations of Sebangau, Selat Nusa, and plantation make up another cluster. The geographically distance is in line with the genetic distance. D. lowii has high level of outcrossing (tm=80.1%) and low level of inbreeding (tm-ts = 12.9%), therefore genetic diversity is relatively high. Explants of the first leaf in the base and middle which were cultured in medium MS + BA 0.2 mg/l + IBA 0.5 mg/l produced somatic embryo. Embryogenic callus cells have formed proembryonic stage: 2-cells, 4-cells, round, globular and torpedo. Sampling based on the genetic diversity of the population was derived from Selat Nusa peat-swamp forest. Exploration of plus D. lowii (criteria: age, stem diameter, latex volume, bark character, tapping methods and environmental conditions, and the physiology of latex cell) should be applied to establish breeding populations. Plus tree propagation can be done by applying the method of somatic embryogenesis.
Kata Kunci : Dyera lowii, keragaman genetik, sistem perkawinan, embrio somatik, kriteria standar pohon plus.
