This study aimed to develop the cacao (Theobroma cacao L.) in vitro regeneration system through somatic embryogenesis on kinetin supplemented DKW medium and somaclonal variation assessment using SSR markers. Callus were initiated from basal petal and staminoid explants cultured on callus induction (CI) medium contained DKW basalt salts and kinetin:2,4-D ratios of 1:15.5, 1:7.8 or 1:3.9 and then transferred onto secondary callus growth (SCG) medium contained WPM basalt salts and kinetin:2,4-D ratios of 1:7.8 or 1:3.9. The calli were then subsequently transferred onto embryo development medium contained DKW basal salts with or without the addition of amino acids, adenine or activated charcoal for the formation of somatic embryos. Nine cacao genotypes were tested for their ability to develop somatic embryos. Results of this study indicated DKW medium supplemented with Kinetin in combination with 2,4-D effectively induced cacao somatic embryogenesis. The highest somatic embryos formation was abtained from kinetin:2,4-D ratio of 1:3.9 and 1:7.8 in CI and SCG medium respectively. Cacao genotype responses were highly explant type dependent. The developed method resulted in a high percentage of somatic embryo formation (5.6-66.7%), germination (50%) and plantlet conversion (65%) and a medium percentage of somaclonal variations based on SSRs marker analysis.

Propagation of Coffea arabica L. through direct and indirect somatic embryogenesis technique is promising for producing large number of coffee seedlings. The objectives of the research were to evaluate methods for direct and indirect somatic embryo-genesis induction of C. arabica var. Kartika. The explants were the youngest fully expanded leaves of arabica coffee. The evalu-ated medium was modified Murashige and Skoog (MS) medium supplemented with a combination of 2.26 µM 2,4-D + 4.54 or 9.08 µM thidiazuron; 4.52 µM 2,4-D + 4.54 or 9.08 µM thidiazuron; or 9.04 µM 2,4-D + 9.08 µM thidiazuron. Both calli (100 mg) and pre-embryos developed from the edge of leaf explants were subcultured into regeneration medium (half strength MS with modified vitamin, supplemented with kinetine 9.30 µM and adenine sulfate 40 mg L-1). The results showed coffee leaf explant cultured on medium containing 2.26 µM 2,4-D + 4.54 or 9.08 µM thidiazuron to induce direct somatic embriogenesis from explant, while that of 4.52 or 9.04 µM 2,4-D + 9.08 µM thidiazuron to induced indirect somatic embrio-genesis. The medium for calli induction from coffee by explants was medium supplemented with 4.52 or 9.04 µM 2,4-D in combination with 9.08 µM thidiazuron. On the other hand, the best medium for activation of induction of somatic embryos was MS medium supplemented with 9.04 µM 2,4-D + 9.08 µM thidiazuron. Based on this results, the first step for developing micropropagation for coffee has been resolved. The subsequent studies will be directed to evaluate agronomic performance of the derived planting materials.

To increase the genetic diversity of sugarcane can be done through induced mutation using gamma ray irradiation. This research was carried out to determine the response and radiosensitivity of calli sugarcane variety (Kidang Kencana) to gamma ray irradiation, and knowing the diversities of phenotypic mutant of sugarcane. The research was conducted at BATAN and ICECRD, from August 2012 until March 2013. This research was arranged in Completely Randomized Design with 6 doses of gamma ray irradiation (0, 10, 20, 30, 40 and 50 Gy). Each treatment consisted of 10 replications. Each replication consists of 5 clumps of calli. The observed variables were calli fresh weight, percentage of regenerated calli, number of shoots, shoot height, leaves number, roots number and plantlets number, calli and mutant phenotype. The results showed that the ability of calli to regenerate and shoot growth decreased with increasing doses of gamma ray irradiation. Radiosensitivity (LD20-LD50) of sugarcane calli Kidang Kencana variety to gamma irradiation were in the range of 10 and 30 Gy doses. Gamma irradiation 10 and 20 Gy doses caused the variability mutant phenotype were very high. It means that gamma irradiation can be used to increase the genetic variability of sugarcane.

<em>Robusta coffee </em>(Coffea canephora)<em> is a cross-pollinated plant, therefore vegetative propagation is necessary to ensure identical traits with parents, such as tissue culture techniques through somatic embryo. The study aimed to find the effect of plant growth regulator 2.4-D and thidiazuron in inducing embryogenic callus, by adding incision area on leaf explant, and to evaluate addition of GA₃ in increasing somatic embryo conversion. The study was conducted from December 2014 to June 2016 in the Tissue Culture Laboratory, IAARD, Bogor. The research consisted of 2 stages. Stage 1 used a complete randomized design of 2 factors; the first factor was a combination of plant growth regulator 2.4-D (1.0 and 2.0 mg/l) and thidiazuron (1.0; 3.0; and 5.0 mg/l), the second factor was leaf incision (slashed and unslashed). Stage 2 used a complete randomized design, with GA₃treatment at different concentrations (0.0; 0.5; and 1.0 mg/l). Observed variables were percentage of callus formation, fresh weight of callus, number of torpedoes, number of somatic embryos at cotyledon stage, and number of germinated embryo. The results showed growth regulatory treatments influenced the percentage of embryogenic callus formation and fresh weight of callus. Extra incision on leaf showed no effect in  embryogenic callus induction. Embryogenic callus inducted using 2.4-D 1.0 mg/l + thidiazuron 5.0 mg/l medium which  then regenerated in ½ MS medium added with kinetin 2 mg/l exhibited  the highest number of germination.  Adding GA₃ 0.1 mg/l in regeneration medium is recommended to increase somatic embryos of Robusta coffee BP 308 clone.</em>

<p>ABSTRAK</p><p>Perbanyakan tebu umumnya dilakukan secara vegetatif mengguna-<br /> kan setek. Teknik ini mempunyai keterbatasan memproduksi jumlah bibit <br /> dalam skala besar. Dalam rangka mendukung peningkatan produktivitas, <br /> maka perlu pemenuhan bibit tebu dalam skala besar. Kultur jaringan <br /> merupakan   teknologi   alternatif   yang   dapat   dikembangkan   untuk <br /> pemenuhan bibit dalam jumlah yang banyak. Tujuan penelitian ini adalah <br /> mendapatkan formulasi media terbaik untuk induksi kalus dan regenerasi <br /> tebu varietas Kidang Kencana dan PSJT 941. Penelitian dilakukan di <br /> Laboratorium Unit Pengelola Benih Unggul Pertanian, Pusat Penelitian <br /> dan  Pengembangan  Perkebunan,  Bogor  dari  bulan  Februari  sampai <br /> September 2012. Penelitian terdiri dari tiga tahap, yaitu induksi kalus, <br /> regenerasi tunas dan perakaran, serta aklimatisasi. Bahan tanaman tebu <br /> yang digunakan adalah daun muda varietas Kidang Kencana dan PSJT 941 <br /> yang masih menggulung. Empat formulasi media digunakan pada tahap <br /> induksi kalus. Sementara itu, pada tahap regenerasi tunas dan perakaran <br /> menggunakan tujuh formulasi media. Aklimatisasi menggunakan media <br /> tanah steril dan kompos (2:1). Percobaan menggunakan Rancangan Acak <br /> Lengkap yang disusun secara faktorial, terdiri atas dua faktor dan diulang <br /> sepuluh kali. Faktor pertama adalah varietas dan kedua adalah formulasi <br /> media. Hasil penelitian menunjukkan media induksi kalus terbaik untuk <br /> varietas  Kidang  Kencana  adalah 2,4-D 9 µM  +  Picloram  4,5  µM, <br /> sedangkan PSJT 941 adalah 2,4-D 13,5 µM. Media regenerasi dapat <br /> digunakan untuk menginduksi tunas sekaligus perakaran. Media regenerasi <br /> terbaik varietas Kidang Kencana dan PSJT 941 adalah IBA 2,46 µM + <br /> BAP 1,33 µM. Kedua varietas dapat diaklimatisasi di rumah kaca dengan <br /> tingkat keberhasilan tinggi (80-100%).</p><p>Kata kunci: Saccharum officinarum, tebu, kultur jaringan, organogenesis, <br />                 perbanyakan</p><p> </p><p>Callus Induction and Plant Regeneration of Two Sugarcane Varieties (Saccharum officinarum L.) through In Vitro</p><p>ABSTRACT</p><p>Generally, sugarcane propagation was done by vegetative cuttings. <br /> The technique had limitation of producing seeds in a large scale. In order <br /> to increase productivity of sugarcane, it is required to provide sugarcane <br /> seeds in large scale. Tissue culture is an alternative technique that can be <br />developed to provide the seeds. The objective of this research was to</p><p>obtain the best formulations for callus induction and regeneration of <br /> Kidang Kencana and PSJT 941 varieties. The study was conducted in the <br /> Laboratory of Superior Farm Seeds Management Unit, Indonesian Agency <br /> for Agricultural Research and Development, Bogor from February until <br /> September 2012. The researches were carried out in three steps, name <br /> lycallus induction, regeneration of shoots and roots, and acclimatization. <br /> Explant  material  used  was  young  rolled  leaves  collected  from  two <br /> sugarcane  varieties (Kidang  Kencana  and  PSJT 941).  Four  media <br /> formulations used for callus induction, while seven media formulations <br /> used for shoots and roots regeneration. Acclimatization used sterile soil <br /> and compost (2:1). The experiment arranged in Factorial Completely <br /> Randomized Design with two factors and ten replications. The first factor <br /> was varieties and second factor was media formulations. The results <br /> showed that the best callus induction media for Kidang Kencana was 2.4-<br /> D 9 µM + Picloram 4.5 µM, while for PSJT 941 was 2.4-D 13.5 µM. <br /> Regeneration  media  could  induce both  shoots  and  roots.  The  best <br /> regeneration media for Kidang Kencana and PSJT 941 were IBA 2.46 µM <br /> + BAP 1.33 µM. They could be acclimatized successfully in green house <br /> with highly percentage (80-100%).</p><p>Key words:  Saccharum officinarum,  sugarcane, tissue culture, organo- genesis, multiplication</p>