Pengaruh Sitokinin, Jenis Eksplan, dan Genotipe terhadap Embriogenesis Somatik Kakao

<p><em>Information on the effect of cytokinins on cacao (</em>Theobroma cacao<em> L.) primary somatic embryogenesis and its interaction with explant types and genotypes is not yet known. This study aimed to evaluate the effect of cytokinins and its interaction with explant types and genotypes on cacao somatic embryogenesis. The study was conducted at tissue culture laboratory of IAARD, Bogor from April until December 2012 and October 2014 until February 2016. Three types of cytokinins i.e. kinetin (0.58, 1.16, and 2.32 </em><em>μ</em><em>M), thidiazuron (0.01, 0.02, and 0.04 </em><em>μ</em><em>M) and benzylaminopurine (0.55, 1.11, and 2.22 </em><em>μ</em><em>M) in combination with 9 </em><em>μ</em><em>M 2,4-D were tested for their effectiveness in inducing somatic embryogenesis from petals and staminoid explants of Cimanggu 1 genotype. Furthermore, three levels of kinetin (0.58, 1.16, and 2.32 </em><em>μ</em><em>M</em><em>) also in combination with 9 </em><em>μ</em><em>M 2,4-D were evaluated for their influences on the somatic embryogenesis from petals and staminoid explants of three cacao genotypes i.e. Sulawesi 02, ICCRI 04 and Cimanggu 3. The result demonstrated that 2.32 </em><em>μ</em><em>M kinetin and staminoids explant were more effective to induce cacao somatic embryogenesis of Cimanggu 1 genotype (7%, 0.23 embryos/explant). Additionally, there were interaction effects between the level of kinetin with explant types and genotype on the percentage of explants forming embryo at 12 weeks after culture. The highest percentage of somatic embryo formation was shown by ICCRI 04 genotype with the use of petals explant and a kinetin level of 1.16 </em><em>μ</em><em>M (31.85%), but not significantly different from the level of kinetin 2.23 </em><em>μ</em><em>M (25.55%). The formation of primary somatic embryos of cacao is largely determined by the type and level of cytokinins, type of explant, and genotype.</em></p>

Effect of cryopreservation and post-cryopreservation somatic embryogenesis on the epigenetic fidelity of cocoa (Theobroma cacao L.)

While cocoa plants regenerated from cryopreserved somatic embryos can demonstrate high levels of phenotypic variability, little is known about the sources of the observed variability. Previous studies have shown that the encapsulation-dehydration cryopreservation methodology imposes no significant extra mutational load since embryos carrying high levels of genetic variability are selected against during protracted culture. Also, the use of secondary rather than primary somatic embryos has been shown to further reduce the incidence of genetic somaclonal variation. Here, the effect of in vitro conservation, cryopreservation and post-cryopreservation generation of somatic embryos on the appearance of epigenetic somaclonal variation were comparatively assessed. To achieve this we compared the epigenetic profiles, generated using Methylation Sensitive Amplified Polymorphisms, of leaves collected from the ortet tree and from cocoa somatic embryos derived from three in vitro conditions: somatic embryos, somatic embryos cryopreserved in liquid nitrogen and somatic embryos generated from cryoproserved somatic embryos. Somatic embryos accumulated epigenetic changes but these were less extensive than in those regenerated after storage in LN. Furthermore, the passage of cryopreserved embryos through another embryogenic stage led to further increase in variation. Interestingly, this detected variability appears to be in some measure reversible. The outcome of this study indicates that the cryopreservation induced phenotypic variability could be, at least partially, due to DNA methylation changes.Key messagePhenotypic variability observed in cryostored cocoa somatic-embryos is epigenetic in nature. This variability is partially reversible, not stochastic in nature but a directed response to the in-vitro culture and cryopreservation.

Embriogenesis somatik langsung dan regenerasi planlet kopi arabika (Coffea arabica) dari berbagai eksplan Direct somatic embryogenesis and regeneration of arabica coffee plantlets (Coffea arabica) from different explants

SummaryTissue culture technique for arabica coffeefaces some problems, mainly in plantletsregeneration from cultured explants. Theobjectives of this experiment were to examine theeffect 2,4-D and 2-ip combinations on somaticembryogenesis and regeneration of arabicacoffee from several different explants. Basalmedium used in this experiment was MS mediumwith ½ concentration of macro and micro salts.Experiment to induce primary somatic embryos(SE) was arranged in factorial randomizedcomplete design with 10 repeats. The first factorwas the type of explants, leaf, epicotyl, hipocotyland root explants. The second factor was plantgrowth regulator i.e. combination of 1  M 2,4-Dwith 5, 10, 15, 20  M and combination of 5  M2,4-D with 5, 10, 15 and 20  M 2-ip. To multiplySE, secondary SE was induced from primary SEon medium containing combination of 0.6  MIAA and 13.3; 17.8 and 22.2  M BAP.Cotyledonary SE were germinated on mediacontaining GA 3 (0, 5, 10 and 15  M), and thenregenerated on medium free of growth regulator.Plantlets with 4-5 leaf pairs were transfered intothe soil medium for acclimatization. The resultsshow that primary SE can be induced from allexplants with the highest frequency on mediumcontaining 1  M 2,4-D and 15  M 2-ip.Induction of primary SE, in leaf explant wasmore effective than other explants. Mediumcontaining 0.6  M IAA and 22.2  M BAP gavethe highest percentage of SE multiplication i.e.52.6% with average SE number of 6.25. Plantletsregeneration can be conducted by culturing SEon maturation medium free of growth regulatorfor one month followed by germinating onmedium containing GA 3 , and then culturing onmedium free of growth regulator again. Thehighest percentage of germinated embryos wasobtained after three weeks and six weekscultured in the medium containing 5  M GA 3 , i.e49% and 90.15 respectively. From total plantletsobtained, 75% of them were normal. Sixtypercents of the young plants grew well in thegreenhouse.RingkasanTeknik kultur jaringan tanaman kopi arabikamasih menghadapi beberapa kendala terutamapada tingkat regenerasi planlet dari eksplan yangdikulturkan. Penelitian ini bertujuan untukmengetahui pengaruh kombinasi 2,4-D dan 2-ipterhadap embriogenesis somatik dan regenerasikopi arabika dari berbagai eksplan. Media dasaryang digunakan adalah medium MS ½konsentrasi garam makro dan mikro. Percobaaninduksi embrio somatik (ES) primer disusunmenurut rancangan acak lengkap faktorial dengan10 ulangan. Faktor pertama adalah jenis eksplan,erdiri atas daun, epikotil, hipokotil dan akar invitro. Faktor kedua adalah zat pengatur tumbuh,yaitu kombinasi 1 M 2,4-D dengan 5, 10, 15dan 20M 2-ip, serta kombinasi 5 M 2,4-Ddengan 5, 10, 15 dan 20 M 2-ip. Untuk mem-perbanyak jumlah ES yang didapatkan, dilakukaninduksi ES sekunder dari ES primer pada mediumyang mengandung kombinasi 0,6 M IAA dan13,3; 17,8 dan 22,2 M BAP. ES fase kotiledonkemudian dikecambahkan pada medium yangmengandung GA 3 (0, 5, 10 dan 15 M) danselanjutnya diregenerasikan pada medium tanpazat pengatur tumbuh. Planlet yang mempunyai4-5 pasang daun dipindahkan ke medium tanahuntuk aklimatisasi. Hasil yang diperolehmenunjukkan bahwa ES primer dapat diinduksipada semua eksplan yang digunakan denganfrekuensi tertinggi pada medium yang me-ngandung 1 M 2,4-D dan 15 M 2-ip. InduksiES primer pada eksplan daun lebih efektifdibandingkan eksplan lainnya. Untuk per-banyakan ES, medium yang mengandung IAA0,6 M dan BAP 22,2 M memberikanpersentase tertinggi pembentukan ES sekunderyaitu 52,6% dengan rata-rata jumlah ES 6,25.Regenerasi planlet dapat dilakukan denganmengkulturkan ES pada medium maturasi tanpazat pengatur tumbuh selama satu bulan, kemudiandikecambahkan dalam medium yang mengan-dung GA 3 , dan selanjutnya dipindah ke mediumtanpa zat pengatur tumbuh kembali.Perkecambahan ES tertinggi diperoleh padamedium dengan penambahan GA 3 5 M yaitu40,9% setelah tiga minggu dan 90,1% setelahenam minggu. Dari total planlet diperoleh 75%planlet normal. Hasil aklimatisasi menunjukkanbahwa 60% bibit mampu bertahan di rumah kaca.

Embriogenesis somatik langsung dan regenerasi planlet kopi arabika (Coffea arabica) dari berbagai eksplan Direct somatic embryogenesis and regeneration of arabica coffee plantlets (Coffea arabica) from different explants

SummaryTissue culture technique for arabica coffeefaces some problems, mainly in plantletsregeneration from cultured explants. Theobjectives of this experiment were to examine theeffect 2,4-D and 2-ip combinations on somaticembryogenesis and regeneration of arabicacoffee from several different explants. Basalmedium used in this experiment was MS mediumwith ½ concentration of macro and micro salts.Experiment to induce primary somatic embryos(SE) was arranged in factorial randomizedcomplete design with 10 repeats. The first factorwas the type of explants, leaf, epicotyl, hipocotyland root explants. The second factor was plantgrowth regulator i.e. combination of 1  M 2,4-Dwith 5, 10, 15, 20  M and combination of 5  M2,4-D with 5, 10, 15 and 20  M 2-ip. To multiplySE, secondary SE was induced from primary SEon medium containing combination of 0.6  MIAA and 13.3; 17.8 and 22.2  M BAP.Cotyledonary SE were germinated on mediacontaining GA 3 (0, 5, 10 and 15  M), and thenregenerated on medium free of growth regulator.Plantlets with 4-5 leaf pairs were transfered intothe soil medium for acclimatization. The resultsshow that primary SE can be induced from allexplants with the highest frequency on mediumcontaining 1  M 2,4-D and 15  M 2-ip.Induction of primary SE, in leaf explant wasmore effective than other explants. Mediumcontaining 0.6  M IAA and 22.2  M BAP gavethe highest percentage of SE multiplication i.e.52.6% with average SE number of 6.25. Plantletsregeneration can be conducted by culturing SEon maturation medium free of growth regulatorfor one month followed by germinating onmedium containing GA 3 , and then culturing onmedium free of growth regulator again. Thehighest percentage of germinated embryos wasobtained after three weeks and six weekscultured in the medium containing 5  M GA 3 , i.e49% and 90.15 respectively. From total plantletsobtained, 75% of them were normal. Sixtypercents of the young plants grew well in thegreenhouse.RingkasanTeknik kultur jaringan tanaman kopi arabikamasih menghadapi beberapa kendala terutamapada tingkat regenerasi planlet dari eksplan yangdikulturkan. Penelitian ini bertujuan untukmengetahui pengaruh kombinasi 2,4-D dan 2-ipterhadap embriogenesis somatik dan regenerasikopi arabika dari berbagai eksplan. Media dasaryang digunakan adalah medium MS ½konsentrasi garam makro dan mikro. Percobaaninduksi embrio somatik (ES) primer disusunmenurut rancangan acak lengkap faktorial dengan10 ulangan. Faktor pertama adalah jenis eksplan,erdiri atas daun, epikotil, hipokotil dan akar invitro. Faktor kedua adalah zat pengatur tumbuh,yaitu kombinasi 1 M 2,4-D dengan 5, 10, 15dan 20M 2-ip, serta kombinasi 5 M 2,4-Ddengan 5, 10, 15 dan 20 M 2-ip. Untuk mem-perbanyak jumlah ES yang didapatkan, dilakukaninduksi ES sekunder dari ES primer pada mediumyang mengandung kombinasi 0,6 M IAA dan13,3; 17,8 dan 22,2 M BAP. ES fase kotiledonkemudian dikecambahkan pada medium yangmengandung GA 3 (0, 5, 10 dan 15 M) danselanjutnya diregenerasikan pada medium tanpazat pengatur tumbuh. Planlet yang mempunyai4-5 pasang daun dipindahkan ke medium tanahuntuk aklimatisasi. Hasil yang diperolehmenunjukkan bahwa ES primer dapat diinduksipada semua eksplan yang digunakan denganfrekuensi tertinggi pada medium yang me-ngandung 1 M 2,4-D dan 15 M 2-ip. InduksiES primer pada eksplan daun lebih efektifdibandingkan eksplan lainnya. Untuk per-banyakan ES, medium yang mengandung IAA0,6 M dan BAP 22,2 M memberikanpersentase tertinggi pembentukan ES sekunderyaitu 52,6% dengan rata-rata jumlah ES 6,25.Regenerasi planlet dapat dilakukan denganmengkulturkan ES pada medium maturasi tanpazat pengatur tumbuh selama satu bulan, kemudiandikecambahkan dalam medium yang mengan-dung GA 3 , dan selanjutnya dipindah ke mediumtanpa zat pengatur tumbuh kembali.Perkecambahan ES tertinggi diperoleh padamedium dengan penambahan GA 3 5 M yaitu40,9% setelah tiga minggu dan 90,1% setelahenam minggu. Dari total planlet diperoleh 75%planlet normal. Hasil aklimatisasi menunjukkanbahwa 60% bibit mampu bertahan di rumah kaca.

Somatic Embryogenesis and Organogenesis of Biofuel Plant Cassava (Manihot esculenta Crantz) Chinese Cultivars

2, 4-D and picloram were compared for their ability to the induction of somatic embryogenesis in Chinese cassava (Manihot esculenta Crantz) cultivars SC5, SC6, SC7 and SC8. In all four cultivars tested, both 2, 4-D and picloram had the capacity to induce primary somatic embryos from axillary buds. And the two hormones were also suitable for subculture of somatic embryos of three cultivars SC5, SC6 and SC8. However both 2, 4-D and picloram can not keep the activity of somatic embryos of cultivar SC7. For organogenesis, cotyledon matured for 10~15 days were better than others.