scholarly journals Induction of somatic embryos of recalcitrant genotypes of Theobroma cacao L.

2019 ◽  
Vol 133 (1) ◽  
pp. 13552
Author(s):  
Koné Daouda ◽  
Kouassi Kan Modeste ◽  
N’Nan Alla Oulo ◽  
Koffi Kouablan Edmond
2020 ◽  
Vol 20 (4) ◽  
pp. 179 ◽  
Author(s):  
NUR AJIJAH

<p>ABSTRAK</p><p><br />Embriogenesis somatik kakao (Theobroma cacao L.) telah banyak<br />dilaporkan  dengan  penggunaan  zat  pengatur  tumbuh  (ZPT)  yang<br />bervariasi. Penggunaan thidiazuron untuk menginduksi embriogenesis<br />somatik kakao telah dilaporkan melalui dua tahap induksi kalus. Penelitian<br />ini bertujuan untuk mengevaluasi efektivitas thidiazuron menginduksi<br />embriogenesis somatik kakao melalui satu tahap induksi kalus. Penelitian<br />dilaksanakan di Laboratorium Kultur Jaringan Unit Pengembangan Benih<br />Unggul, Badan Litbang Pertanian, Bogor. Empat taraf thidiazuron (0; 2,5;<br />5,0; dan 10 µg/l) dikombinasikan dengan 2,4-D 2 mg/l<br />digunakan untuk<br />menginduksi kalus dan embrio somatik 3 klon kakao (TSH858, Sca6, dan<br />ICS13) menggunakan eksplan mahkota bunga dan staminoid. Media dasar<br />DKW tanpa ZPT digunakan sebagai kontrol. Penelitian disusun dalam<br />rancangan lingkungan acak lengkap dengan lima ulangan. Setiap unit<br />percobaan terdiri dari sepuluh eksplan. Peubah yang diamati meliputi<br />persentase pembentukan kalus umur 2 dan 4 minggu, penampakan visual<br />kalus, persentase eksplan membentuk embrio somatik, dan jumlah embrio<br />somatik per eksplan umur 10 dan 14 minggu. Kalus terbentuk pada media<br />dengan penambahan hanya 2,4-D atau 2,4-D + thidiazuron, namun embrio<br />somatik hanya terbentuk pada media dengan penambahan 2,4-D +<br />thidiazuron. Pembentukan kalus dan embrio somatik sangat dipengaruhi<br />oleh tipe eksplan dan genotipe. Klon Sca6 lebih responsif dibandingkan<br />TSH858 dan ICS13 dan eksplan staminoid lebih responsif dibandingkan<br />mahkota bunga. Hasil studi ini menunjukkan terdapat pengaruh interaksi<br />yang kuat antara ZPT, genotipe, dan tipe eksplan terhadap pembentukan<br />kalus dan embrio somatik kakao serta tidak terdapat perbedaan hasil yang<br />nyata antara pembentukan embrio somatik melalui satu dan dua tahap<br />induksi kalus.<br />Kata kunci: Theobroma cacao L., genotipe, eksplan, zat pengatur tumbuh</p><p>ABSTRACT</p><p><br />Somatic embryogenesis of cacao (Theobroma cacao L.) has been<br />widely reported with varied of plant growth regulators (PGR) used. The<br />use of thidiazuron in inducing somatic embryogenesis of cacao has been<br />reported through a two-step callus induction. The study aimed to evaluate<br />the effectiveness of thidiazuron in inducing somatic embryogenesis of<br />cacao through a one-step of callus induction. The study was conducted at<br />the tissue culture laboratory of Agricultural Seed Development Unit,<br />Indonesian Agency for Agricultural Research and Development, Bogor.<br />Four levels of thidiazuron (0; 2.5; 5.0; and 10 µg/l) in combination with 2<br />mg/l  2,4-D  were  used  for  inducing  callogenesis  and  somatic<br />embryogenesis of three cacao clones (TSH858, Sca6, and ICS13) using<br />petals and staminoids explants. DKW basal medium without PGR was<br />used as a control. The result showed that callus were formed on medium<br />containing only 2,4-D or 2,4-D + thidiazuron, while embryos were only<br />formed on medium containing 2,4-D + thidiazuron. The formation of<br />callus and somatic embryos were highly affected by explant types and<br />genotypes. Sca6 clone was more responsive than TSH858 and ICS13 and<br />staminoids were more responsive than petals. The results of this study<br />revealed that there was a strong interaction between the PGRs, genotypes,<br />and explant types on the formation of cacao callus and somatic embryos.<br />Results of this study also showed no significant difference between the<br />formation of somatic embryos through one and two steps of callus<br />induction.<br />Keywords: Theobroma cacao L., genotypes, explants, plant growth<br />regulators</p>


2018 ◽  
Vol 229 ◽  
pp. 65-76 ◽  
Author(s):  
Liliana Alexandra Pila Quinga ◽  
Angelo Schuabb Heringer ◽  
Hugo Pacheco de Freitas Fraga ◽  
Leila do Nascimento Vieira ◽  
Vanildo Silveira ◽  
...  

2008 ◽  
Vol 27 (4) ◽  
pp. 667-676 ◽  
Author(s):  
Nicolas Niemenak ◽  
Katja Saare-Surminski ◽  
Christina Rohsius ◽  
Denis Omokolo Ndoumou ◽  
Reinhard Lieberei

2008 ◽  
Vol 43 (10) ◽  
pp. 1433-1436 ◽  
Author(s):  
Thiago Édson Ribeiro da Silva ◽  
Luciana Cardoso Cidade ◽  
Fátima Cerqueira Alvim ◽  
Júlio Cézar de Mattos Cascardo ◽  
Marcio Gilberto Cardoso Costa

The objective of this work was to evaluated a procedure for somatic embryogenesis and regeneration of cacao (Theobroma cacao L.) elite clones. Petal explants from cacao clones TSH 565 and TSH 1188 were cultured on PCG and SCG-2 media, for calli growth. Somatic embryos were formed on the surface of embryogenic calli after transfer to embryo development (ED) medium. Clone TSH 565 showed a higher embryogenic potential than TSH 1188. The best combination of carbon source for embryo induction in ED medium was genotype-specific. Embryogenic callus formations increased in micropore tape-sealed Petri dishes, irrespective of cacao genotype. Mature somatic embryos were successfully converted into plantlets.


2016 ◽  
Author(s):  
Raphael Adu-Gyamfi ◽  
Andy Wetten ◽  
Carlos Marcelino ◽  
Rodríguez López

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.


2008 ◽  
Vol 18 (2) ◽  
pp. 152 ◽  
Author(s):  
J-Y. FANG ◽  
A. WETTEN ◽  
R. ADU-GYAMFI

The inability to conserve cocoa (Theobroma cacao L.) germplasm via seed storage and the vulnerability of field collections make the establishment of cryopreserved genebanks for the crop a priority. An effective encapsulation-dehydration based cryopreservation system has been developed for cocoa but because the somatic embryos used for freezing arise after a protracted period of callus culture there is concern about maintenance of genetic fidelity during the process. Microsatellite markers for seven of the 10 cocoa linkage groups were used to screen a population of 189 primary somatic embryo-derived emblings and the 43 secondary somatic embryos they gave rise to. Of the primary somatic embryos, 38.1% exhibited polymorphic microsatellite profiles while for secondary somatic embryos the frequency was 23.3%. The same microsatellite markers used to screen another population of 44 secondary somatic embryos cryopreserved through encapsulation-dehydration revealed no polymorphisms. Scanning electron microscopy showed the secondary somatic embryos were derived from cotyledonary epidermal cells rather than callus. The influence of embryo ontogeny on somaclonal variation is discussed.;


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