<p>Protokol perbanyakan klonal yang efektif dan efisien sangat diperlukan untuk produksi benih berkualitas pada komersialisasi produk unggulan hasil pemuliaan. Penelitian bertujuan untuk mendapatkan protokol perbanyakan klonal Dendrobium ‘Balithi CF22-58’ melalui embriogenesis tidak langsung. Percobaan dilakukan di Laboratorium Kultur Jaringan Balai Penelitian Tanaman Hias dari bulan Januari hingga Desember 2017. Penelitian ini menekankan pada penggunaan jenis eksplan, media, dan sistem kultur. Jenis eksplan yang diuji adalah tunas pucuk, tunas lateral, dan pangkal plantlet dengan tiga media inisiasi [½ Murashige and Skoog (MS) dikombinasikan dengan 1,5 mg/l thidiazuron (TDZ) dan 0,5 mg/l 6-benzylaminopurine (BAP) (MI-1), 2,5 mg/l metathopolin (mT) dan 0,05 mg/l BAP (MI-2), dan 5 mg/l mT dan 0,05 mg/l BAP (MI-3)]; empat media proliferasi, yaitu ½ MS dengan kombinasi: MP-1 (0,75 mg/l TDZ + 0,25 mg/l BAP), MP-2 (1,5 mg/l TDZ + 0,5 mg/l BAP), MP-3 (2,5 mg/l mT + 0,05 mg/l BAP), dan MP-4 (5,0 mg/l+ 0,05 mg/l BAP); dua sistem kultur (padat dan cair); dan tiga media regenerasi MPP-1 (½ MS dengan vitamin penuh (1/2 MS-FV) + 2% charcoal); MPP-2 (½ MS-FV); dan MPP-3 (2 g/l Rosasol 18:18:18 TE). Percobaan disusun menggunakan rancangan acak kelompok faktorial dengan lima ulangan. Hasil penelitian menunjukkan bahwa inisiasi kalus embriogenik (KE) tertinggi, yaitu 38,3% dengan waktu inisiasi 16,8 hari dihasilkan dari eksplan pangkal plantlet pada medium MI-1. Medium MP-2 dan sistem kultur cair mampu mempertahankan proliferasi KE sampai 83,1% dengan rasio penggandaan 3,23 kali. Perkecambahan embrio terbaik sampai 86,9% embrio berkecambah dengan 18,2 kecambah per rumpun dalam waktu 21,3 hari, ditunjukkan pada medium MPP-1, sedangkan pembesaran plantlet terbaik mencapai tinggi plantlet sampai 5 cm, jumlah daun hingga 4,9 helai, dan jumlah akar 2,8, dengan 2,6 cm panjang akar dan 0,27 g bobot basah plantlet, diperoleh pada medium MPP-3. Perbanyakan anggrek dengan protokol ini diperkirakan dapat menghasilkan sekitar 3.000–4.000 plantlet/eksplan/tahun. Protokol hasil penelitian ini sangat potensial diaplikasikan pada perbanyakan klonal Dendrobium melalui kultur jaringan. </p><p><strong>Keywords</strong></p><p><em>Dendrobium</em>; Embriogenesis somatik; Perbanyakan masal; Proliferasi; Sistem kultur </p><p><strong>Abstract</strong></p><p>The effective and efficient clonal propagation protocol is significantly needed for producing qualified seedling for commercialization of superior breeding products. The objective of the study was to establish clonal propagation protocol for Dendrobium ‘Balithi CF22-58’ via indirect somatic embryogenesis. The study was conducted at the Tissue Culture Laboratory in Indonesian Ornamental Crops Research Institute from January to December 2017. The study emphasized to utilize explant source, culture media, and culture system. Explant types were shoot tip, lateral shoot, and basal part of plantlets; three initiation media [half strength Murashige and Skoog (MS) medium containing 1.5 mg/l thidiazuron (TDZ) and 0.5 mg/l 6-benzylaminopurine (BAP) (MI-1), 2.5 mg/l metathopolin (mT) and 0.05 mg/l BAP (MI-2), and 5 mg/l mT and 0.05 mg/l BAP (MI-3)]; four proliferation media (half strength MS medium supplemented with: MP-1 (0.75 mg/l TDZ and 0.25 mg/l BAP), MP-2 (1.5 mg/l TDZ and 0.5 mg/l BAP), MP-3 (2.5 mg/l mT and 0,05 mg/l BAP), and MP-4 (5.0 mg/l and 0.05 mg/l BAP); two culture system were solid and liquid; and three regeneration media viz, MPP-1 (half strength MS medium with full vitamin and 2% activated charcoal); MPP-2 (MR-1 activated charcoal free), and MPP-3 (2 g/l Rosasol 18:18:18 TE). These experiments were arranged using a factorial randomized complete block design with five replications. Results of the study revealed that the highest initiation rate of embryogenic callus (EC) was up to 38.3% in 16.8 days after culture. The EC was regenerated from a basal part on MI-1 medium, MP-2 medium and liquid culture system were able to maintain proliferation of embryogenic callus up to 83.1% with 3.23 multiplication rate. The best embryo germination up to 86.9% with 18.2 germinated embryos per clump within 21.3 days was determined on MPP-1 medium. While the best plantlet performances with 5 cm height of plantlets, 4.9 number of leaves, 2.8 number of roots, 2.6 cm root length, and 0.27 g plantlet fresh weight was obtained MPP-3 medium. With this propagation protocol, 3,000 - 4,000 plantlets/explant/year can be produced. Results of the study have high potential to be applied for in vitro propagation of Dendrobiums.</p>
GENE EXPRESSION DURING INDIRECT SOMATIC EMBRYOGENESIS OF PLANTS
