Kajian Keragaman Agro-Morfologi dan Genetik, Pembibitan Tanaman serta Potensi Minyak Atsiri Pala Asal Jawa Barat

Abstract

Tanaman pala tergolong ke dalam famili Myristicaceae. Famili ini memiliki 20 genus dan sekitar 500 spesies, dengan wilayah persebarannya termasuk di Indonesia. Indonesia menjadi pusat asal (center of origin) dan pusat keragaman genetik pala. Indonesia merupakan produsen pala terbesar dunia yang memasok sekitar 60% dari total kebutuhan pasar pala dunia setiap tahunnya. Salah satu wilayah sentra produksi pala di Indonesia adalah Jawa Barat. Namun informasi keragaman agromorfologi dan genetiknya serta potensinya sebagai penghasil minyak atsiri masih terbatas, sehingga perlu dilakukan suatu kajian. Penelitian bertujuan untuk mengetahui keragaman agromorfologi dan genetik tanaman pala dari wilayah Jawa Barat, serta mengkaji potensi pembibitannya dan keunggulan minyak atsirinya. Penelitian terdiri atas empat topik penelitian. Penelitian ke-1 mencakup kajian karakteristik ekologi wilayah pengembangan pala di Jawa Barat yang mencakup iklim, tanah dan topografi serta karakteristik agro-morfologi tanaman pala dari sentra pengembangan pala Jawa Barat. Hasil penelitian diperoleh informasi bahwa karakteristik ekologi wilayah pengembangan pala di Jawa Barat dengan curah hujan tahunan rata-rata 2380-4100 mm, ketinggian tempat 519-538 m dpl, rentang kelerengan datar (< 8%) sampai landai (8–15%), jenis tanah latosol dan regosol dengan tekstur liat, pH agak masam dan kesuburan tanah sedang terkategori sesuai untuk pengembangan tanaman pala. Berdasarkan karakter morfologinya, tanaman pala yang dikembangkan di wilayah Jawa Barat termasuk jenis pala Banda (Myristica fragrans Houtt), famili Myristicaceae, dengan koefesien kemiripannya mencapai 84%. Pala yang dikembangkan di tiga wilayah pengembangan Jawa Barat juga memiliki potensi produksi yang seragam, dengan bobot buah rata-rata 55 g per buah dan hampir sama dengan pala Banda. Penelitian ke-2 yaitu analisis molekuler DNA pala berbasis marka Simple Sequence Repeats (SSR), dengan menggunakan 17 primer. Analisis keragaman genetik secara molekuler menjadi penting karena karakter tanaman yang muncul (fenotifik) merupakan hasil interaksi antara faktor genetik dengan lingkungannya. Analisis 17 lokus SSR pada 12 sampel pala menghasilkan 177 alel dengan rerata 11,06 alel per lokus, frekuensi alel utama, diversitas gen, heterozigositas, dan PIC berturut-turut 0,4531; 0,6868; 0,8906; 0,6563. 17 lokus SSR kecuali Vseb 3 berhasil membedakan semua sampel pala dengan koefisien kemiripan 0,81 - 0,49 (tingkat keragaman genetik 19-51%) dan membentuk 4 kelompok besar. Kelompok 1 terdiri dari S1 BGR, S2 BGR, S3 BGR, S2 SKB, dan S3 SKB. Kelompok 2 terdiri dari S1 SKB, S3 CJR, dan S1 CJR. Kelompok 3 terdiri dari S2 CJR dan BC02, sedangkan kelompok 4 terdiri dari HB dan HA. Koefisien kemiripan genetik mengindikasikan rendahnya keragaman genetik antar individu. Keragaman genetik pala yang berasal dari Jawa Barat juga tidak mengelompok (dalam satu bubble) berdasarkan wilayahnya dan hasil analisis structure tidak menunjukkan adanya hubungan kekerabatan antara tanaman, tetapi setiap tanaman memiliki data genetik yang relatif sama. Pada penelitian ke-3 dilakukan perbanyakan bibit tanaman pala melalui grafting dengan beberapa jenis batang bawah serta menganalisis senyawa biokimia yang diduga mempengaruhi grafting tanaman. Analisis senyawa biokimia dilakukan dengan metode ekstraksi dilanjutkan dengan analisis kualitatif dan kuantitatif menggunakan Spektrofotometri UV-Vis. Keberhasilan sambungan (grafting) pala ditunjukkan pada penggunaan batang bawah pala Banda dan pala hutan Ambon dan berbeda nyata dengan penggunaan batang bawah pala Bacan. Keberhasilan sambungan bertaut paling tinggi diperoleh dari penggunaan batang bawah pala hutan Ambon mencapai 54,03% dan bertambahnya jumlah daun. Penggunaan batang bawah pala hutan Bacan menunjukkan tidak adanya grafting yang berhasil. Grafting pala yang bertaut dan terus tumbuh ditandai dengan terbentuknya kalus dan bersatunya jaringan batang atas dan batang bawah dengan rata-rata lebar sambungan 24.825,40 nm. Dugaan bahwa senyawa biokimia fenol dapat menghambat pembentukan kalus tidak terbukti dari hasil penelitian ini. Sebaliknya kadar total fenolik yang paling tinggi pada pala Hutan Ambon yaitu 15,620 (mg TAE/g), diduga mendorong pembentukan kalus dan meningkatkan keberhasilan grafting. Penelitian ke-4 yaitu analisis kadar minyak, sifat fisik dan komponen kimia minyak atsiri buah pala asal Jawa Barat serta pengujian potensi minyak atsiri pala sebagai antioksidan dan antibakteri. Ekstraksi minyak atsiri menggunakan metode destilasi dan analisis menggunakan GCMS. Pengujian antioksidan dengan metode DPPH dan uji antibakteri dengan metode cakram. Hasil penelitian menunjukkan kadar minyak atsiri antar aksesi pala tidak berbeda nyata, sedangkan berdasarkan bagian buahnya berbeda nyata dengan P-value 0,02. Fuli memiliki rataan kadar minyak atsiri paling tinggi yaitu 16,76±15,73%. Komponen utama minyak atsiri pala yang dihasilkan diantaranya myristisin, α-pinene, ß-pinene, sabinene, terpine-4-ol, alpha-terpineol, beta-phellandrene, safrole dan 1,3-Benzodioxole,4-methoxy-6-(2-propenyl)-. Pala asal Bogor memiliki kandungan myristisin paling tinggi yaitu 17,07±4,62%. Kadar myristisin minyak pala dari sentra pengembangan Jawa Barat telah memenuhi standar minyak atsiri pala (SNI 06-2388-2006). Kadar minyak atsiri dan myristisin berkorelasi positif dengan faktor lingkungan tanah dan iklim. Minyak atsiri fuli pala memiliki sifat antioksidan sangat kuat hingga lemah, sedangkan minyak atsiri biji dan daging pala memiliki sifat antioksidan sedang dan lemah. Minyak atsiri fuli pala memiliki aktivitas antioksidan yang paling baik dengan nilai IC50 sebesar 173,54 (mg/L) dan persen antioksidan sebesar 67,85%. Minyak atsiri pala berpotensi menghambat perkembangan bakteri Staphylococcus aureus dan Staphylococcus epidermidis, dan minyak atsiri aksesi Cianjur (Jawa Barat) memberikan aktivitas antibakteri yang paling baik dibandingkan dengan aksesi yang lain. Kata kunci : agro-morfologi, genetik pala, grafting, kadar minyak, myristisin

Nutmeg is classified to the Myristicaceae family. This family has 20 genera and approximately 500 species, with distribution areas, including in Indonesia. Indonesia is the center of origin and the center of nutmeg genetic diversity. Indonesia is the world's largest producer of nutmeg which supplies about 60% of the total world market demand for nutmeg each year. One of the centers of nutmeg production in Indonesia is West Java. However, information on the agromorphological and genetic diversity of nutmeg from the West Java and its potential as a producer of essential oils is still limited, so it is necessary to do a study. This study aims to determine the agro-morphological and genetic diversity of nutmeg plants from the West Java region, and study of plant breeding and the potential of nutmeg essential oil. The study consisted of 4 stages experiment. The 1st study includes a study of the ecological characteristics of the nutmeg development area in West Java which includes climate, soil and topography as well as agro-morphological characteristics of nutmeg plants from the West Java nutmeg development center. The results showed that information the ecological characteristics of the nutmeg development area in West Java with an average annual rainfall of 2380-4100 mm, altitude 519-538 m asl (almost suitable location), the range of slope with a flat (< 8%) to sloping (8–15%) category, the Latosol and Regosol soils, with a soil pH (pH 4,78-5,98) and moderate soil fertility. The overall agro-ecological suitability of nutmeg plants in the West Java region was classified as suitable for development. Based on the morphological character, nutmeg plants developed in the West Java region include the Banda nutmeg species (Myristica fragrans Houtt), Myristicaceae family. with a similarity coefficient of 84%. Nutmeg developed in the three development areas of West Java also has uniform production potential with an average fruit weight of 55 g per fruit and almost the same as Banda nutmeg. The 2nd experiment is the molecular analysis of nutmeg DNA based on Simple Sequence Repeats (SSR) markers, using 17 primers. Analysis of molecular genetic diversity is important because the important plant characters (phenotypic) are the result of interactions between genetic factors and their environment. Analysis of 17 SSR loci in 12 samples of nutmeg yielded 177 alleles with a mean of 11.06 alleles per locus, main allele frequency, gene diversity, heterozygosity, and PIC, i.e 0,4531; 0,6868; 0,8906; 0,6563 respectively. 17 SSR loci besides Vseb 3 succeeded in distinguishing all samples of nutmeg with a similarity coefficient of 0,81 – 0,49 (genetic diversity rate 19-51%) and form 4 groups. Group 1 consists of S1 BGR, S2 BGR, S3 BGR, S2 SKB, and S3 SKB. Group 2 consists of S1 SKB, S3 CJR, and S1 CJR. Group 3 consists of S2 CJR and BC02, while group 4 consists of HB and HA. The coefficient of genetic similarity indicates low genetic diversity between individuals. The genetic diversity of nutmeg originating from West Java is also not clustered (in one bubble) by region and the results of the structure analysis do not show any relationship between plants, but each plant has relatively the same genetic data. In the 3rd study, nutmeg plant seeds were propagated through grafting with several types of rootstock, as well as analyzing biochemical compounds suspected of influencing plant grafting, Analysis of biochemical compounds was carried out by extraction method followed by qualitative and quantitative analysis using UV-Vis Spectrophotometry. The success of nutmeg grafting was shown in the use of Banda nutmeg rootstock and Ambon forest nutmeg and was significantly different from the use of Bacan nutmeg rootstock. The highest success of linked joints was obtained from the use of the Ambon forest nutmeg rootstock reaching 54,03% and increasing the number of leaves. The use of Bacan forest nutmeg rootstock shows no successful grafting. Grafting of nutmeg that is linked and continues to grow is characterized by the formation of callus and the union of scion and rootstock tissue with an average joint width of 24.825,40 nm. The approximate that phenol biochemical compounds can inhibit callus formation is not proven from the results of this study. On the other hand, the highest total phenolic content in Ambon Forest nutmeg was 15,620 (mg TAE/g), thought to encourage callus formation and increase grafting success. The 4th experiment aimed to study the analysis of oil content, physical properties and chemical components of nutmeg essential oil from West Java and testing the potential of nutmeg essential oil as an antioxidant and antibacterial. Extraction of essential oils using the distillation method and analyzed using GCMS. Antioxidant test by DPPH method and antibacterial test by disc method. The results showed that the levels of essential oil between accessions of nutmeg were not significantly different, while based on the part of the fruit it was significantly different with a P-value of 0,02. Mace has the highest average essential oil content of 16,76±15,73%. The main components of the nutmeg essential oil produced include: myristisin, α-pinene, ß-pinene, sabinene, terpine-4-ol, alpha-terpineol, beta-phellandrene, safrole dan 1,3-Benzodioxole,4-methoxy-6-(2-propenyl)-. Nutmeg from Bogor has the highest myristicin content, which is 17,07±4,62%. The myristicin content of nutmeg oil from the West Java development center has referred to SNI 06-2388-2006. The levels of essential oil and myristicin positively correlated with soil environmental factors and climate. Mace nutmeg essential oil has very strong to weak antioxidant properties, while nutmeg seed and flesh essential oil has moderate and weak antioxidant properties. Mace nutmeg essential oil has the best antioxidant activity with an IC50 value of 173,54 and an antioxidant percent of 67,85%. Nutmeg essential oil has the potential to inhibit the growth of Staphylococcus aureus and Staphylococcus epidermidis and essential oil from Cianjur (West Java) accession gave the best antibacterial activity compared to other accessions. Keywords: agro-morphological, genetic of nutmeg, grafting, oil content, myristicin