Identifikasi Berbagai Aksesi Sagu (Metroxylon spp.) di Taman Nasional Siberut, Kepulauan Mentawai, Sumatera Barat

Abstract

Tumbuhan sagu (Metroxylon spp.) merupakan salah satu tumbuhan penghasil karbohidrat yang potensial untuk dikembangkan dan memiliki kandungan karbohidrat terbesar dibanding tumbuhan penghasil karbohidrat lain. Keragaman jenis tumbuhan sagu di Indonesia masih banyak yang belum diketahui. Penelitian ini bertujuan mempelajari keragaman tumbuhan sagu berdasarkan karakter morfologi, karakter produksi dan karakter genetik yang dilakukan secara langsung melalui pengukuran (kuantitatif) dan pengamatan visual (kualitatif) di Taman Nasional Siberut, Kepulauan Mentawai, Sumatera Barat. Karakter genetik diamati menggunakan metode Random Amplified Polymorphic DNA (RAPD). Terdapat enam aksesi sagu yang diamati di dua Kecamatan Siberut Barat dan Siberut Utara, yaitu aksesi Saikoat, Limu, Betaet, Ukra, Sirilanggai dan Sibeotcun yang keseluruhan aksesi tersebut termasuk jenis sagu yang tidak berduri. Berdasarkan karakter morfologi, terdapat perbedaan dari keenam aksesi, seperti habitus dan habitat tumbuhan, bentuk tajuk, bentuk dan ukuran batang, jumlah daun, ukuran daun dan anak daun, warna kulit batang, warna empulur, warna pati, serta warna kuncup daun muda anakan. Rata-rata produksi pati kering berbagai aksesi sagu sebesar 312,68 kg batang-1. Aksesi Ukra merupakan aksesi yang memiliki produksi pati kering tertinggi sebesar 544,37 kg batang-1. Produktivitas sagu di Taman Nasional Siberut berdasarkan perhitungan jumlah pohon sagu siap panen per hektar didapatkan produktivitas sagu sebesar 15,79 ton hektar-1 tahun-1. Berdasarkan analisis karakter genetik (RAPD), terdapat keragaman yang cukup dekat dari keenam aksesi sagu yang terdapat di Taman Nasional Siberut, dengan nilai koefisien kemiripan berkisar antara 61% hingga 77%. Aksesi Ukra memiliki nilai koefisien kemiripan paling jauh dengan aksesi yang lainnya yaitu sebesar 61%.

Sago (Metroxylon spp.) is one of the potential carbohydrate-producing plants to be developed and has the largest carbohydrate content compared to other carbohydrate-producing plants. The diversity of sago plant species in Indonesia is still largely unknown. This study aims to study the diversity of sago plants based on morphological, production, and genetic characteristic which were carried out directly through measurements (quantitative) and visual observations (qualitative) in Siberut National Park, Mentawai Islands, West Sumatra. Genetic characters were observed using the Random Amplified Polymorphic DNA (RAPD) method. There were six accessions of sago observed in two sub-districts of West Siberut and North Siberut, namely accessions of Saikoat, Limu, Betaet, Ukra, Sirilanggai, and Sibeotcun all of which included the thornless type of sago. Based on morphological characters, there were differences between the six accessions, such as habitus and plant habitat, crown shape, stem shape and size, number of leaves, leaf size and leaflets, stem bark color, pith color, starch color, and color of young leaf buds. The average dry starch production of various accessions of sago was 312.68 kg stem-1. The Ukra accession was the accession with the highest dry starch production of 544.37 kg stem-1. Sago productivity in Siberut National Park based on the calculation of the number of ready-to-harvest sago trees per hectare obtained sago productivity of 15.79 tons hectare-1 year-1. Based on genetic character analysis (RAPD), there is a fairly close diversity of the six sago accessions found in Siberut National Park, with similarity coefficient values ranging from 61% to 77%. Ukra accession has the closest similarity coefficient with other accessions, which is 61%.