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Evaluation of the flowering and fruiting of cacao trees. The flowering and fruit production of each tree was recorded every fall and spring from 35 to 57 mo. after planting (2-03 to 11-05) and the percentages of flowering and fruiting trees were calculated for each propagation method. (A) Percentage flowering trees. (B) Percentage fruiting trees. PSE primary somatic embryogenesis, SSE secondary somatic embryogenesis, MP micropropagation, ORC orthotropic rooted cutting.
Source publication
Somatic embryogenesis is an in vitro clonal propagation method with potential to contribute to the improvement of cacao varieties. Before using this technology
for commercial production, it is essential that somatic embryogenesis-derived plants be tested in field conditions. Therefore,
we established a field test at Union Vale Estate, Saint Lucia....
Contexts in source publication
Context 1
... developmental process evaluated was the cycli- cal changes in flowering that occur in cacao as a result of seasonal changes in rainfall. Here, we present the percentage of flowering trees recorded from December 2003 (35 mo. in the field) to November 2005 (57 mo. in the field) (Fig. 4A). During that period, all trees evaluated had developed jorquettes. A significantly higher percentage (p=8.47 E- 15) of plants, regardless of propagation method, flowered during the spring months (April and May) compared to the winter months (November, December, and January). Thus, the flowering occurred mainly at the end of the dry ...
Context 2
... are often aborted at an early stage. As they mature, the trees can support fruit development, but the number of fruits is also regulated by physiological vigor. Thus, the date of first fruit production is indicative of the general physiological and developmental stage of a cacao tree. The percentage of trees producing mature fruit is presented in Fig. 4B. During this field test, mature fruit development was observed as early as 19 mo. after planting on several of the PSE and seed-propagated plants. Overall, the percentage of trees producing fruit remained low initially then rose to about 40% of the trees (p=6.5 E-12) at 57 wk. This percentage will likely continue to increase as the ...
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Citations
... An evaluation study was designed prior to the field phase to measure the effect of heat stress during somatic embryo development (Ajijah and Inoue 2020). Some of the most relevant parameters have already been measured for some genotypes, such as phenotype and development (Maximova et al. 2008), genetic stability (Henao-Ramírez et al. 2021), stigmatic receptivity in the pollination process (Entuni et al. 2021), the evaluation of intended genotypes for rootstocks as a strategy to standardize the high-quality plant production system (Osorio Montoya et al. 2022), and the quality of the cocoa bean, such as the yield and flavor of the trees (Goenaga et al. 2015). Although direct or indirect SSE can increase clonal production, the variation in the response that is observed between genotypes exhibits notable differences between the supplied hormones; therefore, it is necessary to optimize the hormonal balance and type of hormone, as well as the type of explant for each genotype (Tan and Furtek 2003;Henao-Ramírez and Urrea-Trujillo 2020). ...
Theobroma cacao and T. bicolor are among the most important agricultural crops of the Mexican tropics. Currently, in Mexico, the propagation of these crops is performed via seeds, which indicates that demand exceeds production. In this context, somatic embryogenesis (SE) is an alternative to this approach. Thus, we evaluated the presence of embryogenic genotypes of T. cacao and T. bicolor in the Papaloapan Basin of Mexico with the idea of implementing this technology in the region. The analysis of the phenotypic expression of the floral whorls demonstrated that, unlike T. bicolor, the combination of 6-benzylaminopurine and 2,4-dichlorophenoxyacetic acid induces different morphogenetic responses in the genotypes that were evaluated in the primary callus phase of T. cacao. Staminodia presented with the highest percentage of caulogenesis in T. cacao, whereas T. bicolor presented with the highest frequency of caulogenesis in Staminodia and carpels. Some calli differentiated in the roots to a greater extent than those derived from the staminodes of T. cacao. The calli of T. bicolor did not differentiate. A parallel study using thidiazuron as an inducer demonstrated similar results for calli of both species; however, rhizogenesis from staminodes was 50% lower for the evaluated genotypes of T. cacao. Staminodes were the only structures that demonstrated primary somatic embryogenesis (PSE) in 66% of the T. cacao genotypes that were evaluated by using benzylaminopurine. Finally, secondary somatic embryogenesis (SSE) was evaluated in cotyledons and reached a 60% success rate, of which 95.48% were normal somatic embryos. Both types of embryogenesis were morphologically characterized using optical and/or scanning electron microscopy.
... Alternatives such as tissue culture, through somatic embryogenesis, allow the clonal propagation of superior cocoa genotypes with the same genetic backgrounds. This biotechnological tool was employed in a wide variety of cocoa genotypes [9,10]. ...
Cocoa (Theobroma cacao L.) is the raw material for the worldwide chocolate industry. To ensure high quality and efficient field production, the industry relies on a uniformity of elite cocoa plants, which can be achieved through vegetative propagation methods like somatic embryogenesis. However, the low yield rate in the multiplication and regeneration of cocoa plants remains a challenge for basic research. To obtain a greater number of secondary somatic embryos (SSE) in cocoa, the effect of three osmoregulators on the disc cells of primary somatic embryos (PSE) of cocoa was studied. PSE was induced from cocoa staminodes of genotype I52. Epicotyls were selected from PSE at the torpedo and cotyledon stages, segmented into 3 mm discs, and placed in a secondary callus growth medium. The explants were transferred to embryo development medium 3, where they were exposed to the osmoregulatory polyethylene glycol (PEG), mannitol, and sorbitol at the following concentrations: 0%, 1%, 3%, and 5%. D-Mannitol at 3% and D-Sorbitol at 1% increased the number of SSE at the torpedo, globular, and cotyledon stage per explant. The culture medium with 1% PEG significantly increased the formation of SSE in the globular and cotyledonal stages. The results presented a positive effect of the osmoregulators on the formation of cocoa SSE.
... In Coffea arabica, it was also observed that SE emblings were more vigorous than seedlings, and the observed vigor in the nursery was carried over to field performance as these plants were more precocious than seedlings and yielded coffee beans one year earlier than seedlings [49]. Field performance of Theobroma cacao propagated via SE also showed normal phenotypes in field conditions and similar morphological parameters when compared to plants propagated by traditional methods [50]. The Fv/Fm (maximum yield of PSII photochemistry, i.e., the quantum efficiency if all PSII centers were open) results showed that plants derived from organogenesis (CB2, CB3) suffered more with the acclimatization process. ...
Tamarillo (Solanum betaceum Cav.) is a subtropical solanaceous tree with increasing agronomic interest due to its nutritious edible fruits. Growing demand for tamarillo plants and fruits requires optimization of existing propagation methods and scaled-up systems for large-scale cloning of selected germplasm. Three in vitro protocols have been used to micropropagate tamarillo: (1) axillary shoot proliferation in a semisolid medium, (2) organogenesis, and (3) somatic embryogenesis procedures. Variables such as the age of the established shoot cultures and rooting treatments were also analyzed. The morphological and physiological quality of acclimatized plants derived from all the methodologies were compared, with seed-derived plants used as a control group. Overall, the results show that in vitro-derived plants have a similar development to seed-derived plants. Micropropagation by axillary shoot proliferation was highly efficient, with rooting rates above 80% in most treatments. Organogenesis induction was more effective from lamina explants using MS media with 2.0 mg·L−1 6-benzylaminopurine. Both organogenesis and somatic embryogenesis-derived plants were also morphologically and physiologically equivalent to seed and axillary shoot-derived plants. The specificities of each micropropagation method are discussed.
... Hence, SE has been used for numerous agricultural species such as coffee (Zamarripa et al., 1991;Van Boxtel and Berthouly, 1996;Etienne et al., 1997a), cocoa (Aguilar et al., 1992;Loṕez-Baéz et al., 1993;Alemanno et al., 1996;Maximova et al., 2002;Niemenak et al., 2008), and citrus (Tomaz et al., 2001;Pan et al., 2009), and forest species, including conifers (Lelu-Walter et al., 2006;Montalbań et al., 2012;Kim, 2015;Maruyama and Hosoi, 2019) and tropical and temperate angiosperms (Pintos et al., 2008;Lardet et al., 2009;Correia et al., 2012;Corredoira et al., 2015;Mignon and Werbrouck, 2018). However, only a few species have reproducible protocols for large-scale propagation and commercial planting (Etienne and Bertrand, 2001;Ducos et al., 2007a;Ducos et al., 2007c;Maximova et al., 2008;Etienne et al., 2012;Etienne et al., 2018). For most species, the commercial application of SE has many limitations associated with the genotype (Pais, 2019), low quality of the embryos, problems with embryo maturation and conversion into a plant (Jimeńez, 2005), somaclonal variation (SV), and lack of reproducibility of the process (Etienne et al., 2012). ...
Culture in temporary immersion systems (TIS) is a valuable tool for the semi-automation of high frequency somatic embryogenesis of coffee. This system allows the intermittent exposure of explants to liquid medium in cycles of specific frequency and duration of immersion with renewal of the culture atmosphere in each cycle. TIS have revolutionized somatic embryogenesis of coffee plants as an alternative for scaling up and reducing costs associated with labor-intensive solid media culture. In Central America, somatic embryogenesis is employed on a commercial scale to produce F1 Coffea arabica hybrids. In Asia and Africa, somatic embryogenesis is used for the multiplication of selected genotypes of C. arabica and C.canephora. Somatic embryogenesis of coffee plants is considered a model system for woody species due to its biological versatility and low frequency of somaclonal variation. Nevertheless, the success of somatic embryogenesis for mass propagation of coffee plants depends on the development, optimization, and transfer of complementary technologies. Temporary immersion using the RITA® bioreactor is, so far, the best complementary tool for somatic embryogenesis of Arabica coffee for a single recipient with simple changes in liquid media. Likewise, high volume bioreactors, such as 10-L glass BIT® and 10-L flexible disposable plastic bags, have been successfully used for somatic embryogenesis of other coffee species. These bioreactors allow the manipulation of thousands of embryos under semi-automated conditions. The protocols, advantages, and benefits of this technology have been well documented for organogenesis and somatic embryogenesis pathways. However, adaptation in commercial laboratories requires technical and logistical adjustments based on the biological response of the cultures as well as the costs of implementation and production. This review presents the historical and present background of TIS and its commercial application and, in particular, pertinent information regarding temporary immersion culture for C. arabica somatic embryogenesis. The main limitations of this technology, such as hyperhydricity, asynchrony, and developmental abnormalities, are examined, and a critical analysis of current knowledge regarding physiological, biochemical, and molecular aspects of the plant response to temporary immersion is offered. Further, perspectives are provided for understanding and solving the morpho-physiological problems associated with temporary immersion culture of coffee plants.
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... On a different note, all cocoa trees flowered after 538 days (within 2 years from transplanting) with no difference among clones and propagation source. These findings corroborated the work of [23]. The genetic fidelity analysis with ten SSR primers produced about 206 reproducible fragments or alleles ( Table 4). ...
Morphological and genetic characterization of MCBC1, PBC230, KKM22 and KKM4 cocoa clones derived from staminode and immature zygotic embryo culture were compared with those conventionally grafted. Somatic embryogenesis culture successfully produced true-to-type progenies of elite cocoa clones of MCBC1, PBC230, KKM22 and KKM4 (from staminode culture). Phenotype variations (p < 0.05) were observed only in KKM4 clone from immature zygotic embryo culture which exhibited lower quantities in the fresh pod weight, number of flat beans per pod, seed length, seed width and individual seed weight. The genetic stability of the cultured clones was tested using fragment analysis with 12 SSR primers to validate these results. Eleven of these SSR primers detected mutations only in the allelic profiles of KKM4 clone from immature zygotic embryo. These results validated those variations in KKM4 clones of immature zygotic embryo culture were due to interactions between genotypic and explant types. Unfortunately, these variations were negative attributes to cocoa productivity. Thus, it is suggested that successful production of true-to-type KKM4 cocoa clone should consider other means of propagation including modification of the culture conditions. HIGHLIGHTS It is crucial to evaluate and confirm the quality of the immature zygotic and staminode regenerated cocoa plant before using the culture technique for commercial production The quality can be detected in both phenotype and genotype by comparing the regenerated cocoa plant with those regenerated from the conventional asexual propagation method of grafting Phenotype and genotype differences were only observed in KKM4 clone regenerated from immature zygotic embryo culture and thus validated that this clone exhibited variation KKM4 clone from immature zygotic embryo culture which has lower quantities in the fresh pod weight, number of flat beans per pod, seed length, seed width and individual seed weight confirmed the negative effect of using immature zygotic embryo explant for KKM4 clone propagation. It is suggested to modify the culture technique GRAPHICAL ABSTRACT
... To date, some researchers such as Ajijah et al. [8] Maximova et al. [9], Masseret et al. [10], Miller [6] and Goenaga et al. [11] have successfully introduced somatic embryogenesis cultured cocoa plant into the field. The authors reported that the regenerated cocoa plants exhibited normal phenotype and growth characteristics similar to those propagated by conventional methods. ...
... Another developmental process evaluated in this study is the time of first flowering. Our results are comparable with those found by Maximova et al. [9]. The period to first flowering averaged 561 days (within two years) for all cocoa trees. ...
This study was conducted to compare the agronomic performance of four elite cocoa clones (MCBC1, KKM22, KKM4 and PBC230) regenerated from staminode and immature zygotic embryo culture with conventional grafted cocoa clones. From the results, it was found that the KKM4 clone propagated from immature zygotic embryo culture exhibited variations in the fresh pod weight (339.6 g), fresh individual seed weight (4.13 g) and number of flat beans per pod (4 beans) compared with the rest of the regenerated clones. The genetic stability of the somatic embryogenesis cultured clones and the donor clones was then tested using fragment analysis with five SSR primers, i.e. mTcCIR7, mTcCIR18, mTcCIR22, mTcCIR33 and mTcCIR40. Four of these primers identified variations in the allele size and allele addition in KKM4 clone from immature zygotic embryo. Molecular analysis validated that the difference in agronomic performance of the KKM4 clone from immature zygotic embryo culture was due to genetic mutation created during the immature zygotic embryo culture process.
... To date, some researchers such as Ajijah et al. [8] Maximova et al. [9], Masseret et al. [10], Miller [6] and Goenaga et al. [11] have successfully introduced somatic embryogenesis cultured cocoa plant into the field. The authors reported that the regenerated cocoa plants exhibited normal phenotype and growth characteristics similar to those propagated by conventional methods. ...
... Another developmental process evaluated in this study is the time of first flowering. Our results are comparable with those found by Maximova et al. [9]. The period to first flowering averaged 561 days (within two years) for all cocoa trees. ...
This study was conducted to compare the agronomic performance of four elite cocoa clones (MCBC1, KKM22, KKM4 and PBC230) regenerated from staminode and immature zygotic embryo culture with conventional grafted cocoa clones. From the results, it was found that the KKM4 clone propagated from immature zygotic embryo culture exhibited variations in the fresh pod weight (339.6 g), fresh individual seed weight (4.13 g) and number of flat beans per pod (4 beans) compared with the rest of the regenerated clones. The genetic stability of the somatic embryogenesis cultured clones and the donor clones was then tested using fragment analysis with five SSR primers, i.e. mTcCIR7, mTcCIR18, mTcCIR22, mTcCIR33 and mTcCIR40. Four of these primers identified variations in the allele size and allele addition in KKM4 clone from immature zygotic embryo. Molecular analysis validated that the difference in agronomic performance of the KKM4 clone from immature zygotic embryo culture was due to genetic mutation created during the immature zygotic embryo culture process.
... The first research about field performance of plant propagated via SE was realized by Maximova et al. (2008). At Union Vale Estate, Saint Lucia, nine genotypes were planted in a field. ...
The debate on the adoption and development of GMOs continues today. The polarizations on their use have been established and do not seem to change. This polarization has also been established in Latin America, although two countries permit the cultivation of GMOs (Brazil and Argentina). After 30 years of the first GMO plant, what happened in Latin America? What position have your countries taken on the adoption, adaptation, and development of GM crops? It seems that the struggle for the development of these crops originated on other continents, but their consequences had an impact in Latin America. This debate has meant rising revenues in some countries and the delay of others in the use of this powerful technology. Is it ethical? This debate has left some countries in Latin America and the Caribbean in a technological unit, and others have been able to close the gap between the developer countries and them. GMO technology continues to be surrounded by controversial debates involving different actors. This chapter draws attention to the conflicts generated in polarized contexts and shows how, in situations of a wanted polarization, strategies are used only to defend themselves and maintain control of the situation in both positions. The point of view is from the scientific and technological development.
... The first research about field performance of plant propagated via SE was realized by Maximova et al. (2008). At Union Vale Estate, Saint Lucia, nine genotypes were planted in a field. ...
The attack of pests and diseases represents one of the main limitations for agricultural production in the Neotropical region. The intensification of trade between Latin American countries, the Caribbean, and other regions, among other factors, has resulted in the introduction of a large number of invasive pests in the Neotropical region, affecting crop production and causing large significant losses. Despite efforts to prevent their entry to Latin America and the Caribbean, through the establishment of quarantine systems in the different countries and the implementation of tactics to reinforce phytosanitary surveillance, each year new pests are reported to be introduced in areas where they were not present. This when added to the effects of climate change, represents a challenge for plant protection since it favours the displacement of pests to new areas due to the increase of temperature and changes in the climatic conditions, facilitating the establishment of some introduced species. This chapter presents the use of biological control agents through the implementation of programmes adapted to local conditions as a key strategy for the sustainable management of pests currently present in and potential pests to the region. Initiatives are also presented to strengthen the quarantine system and phytosanitary surveillance in a joint effort with institutions and government agencies of the countries where CABI implements the Plantwise and Action on Invasives programmes, and sustainable production projects with the objective of reinforcing food security in Latin American and the Caribbean countries.
... Research on cryopreservation, tissue culture and somatic embryogenesis (SE) in cacao has been undertaken for decades (Figueira and Yanick 1995;Guiltinan 2007;Maximova et al. 2008;Pence 1995;Sena Gomes et al. 2015;Shires et al. 2017;Sondahl et al. 1993) and is still in progress (Ramirez et al. 2018). Tissue culture and somatic embryogenesis have been tested as methods to facilitate propagation of cacao (Adu-Gyamfi et al. 2016;Alemanno et al. 1996;Goenaga et al. 2015;Guiltinan 2007;Guiltinan et al. 2008;Maximova et al. 2005). ...
... Tissue culture and somatic embryogenesis have been tested as methods to facilitate propagation of cacao (Adu-Gyamfi et al. 2016;Alemanno et al. 1996;Goenaga et al. 2015;Guiltinan 2007;Guiltinan et al. 2008;Maximova et al. 2005). The advantages of plant tissue culture for propagation of cacao have been elaborated by Adu-Gyamfi et al. (2016); Guillou et al. (2014); Juárez Gámez (2012) and Maximova et al. (2005Maximova et al. ( , 2008. One is the avoidance of the dissemination of diseases, which can be Quainoo et al. (2008) observed that progressive elimination of the cocoa swollen shoot virus (CSSV) in infected trees occurred from primary embryogenesis to secondary embryogenesis. ...
... The use of tissue culture via somatic embryogenesis (SE), using immature flowers, for multiplication of cacao planting material has only been done on a limited scale in cocoa producing countries such as Brazil, Ecuador, Ghana, Indonesia, Puerto Rico and Vietnam (Guillou et al. 2014;Maximova et al. 2008). Nestlé has developed a collection of SE trees in Ecuador, which is maintained in the field and the greenhouse (Guillou et al. 2014). ...
The suboptimal productivity in cocoa farmers’ fields, particularly those of small-holders who produce over 80% of the global supply, and the demand for cocoa that meets stringent quality and flavor criteria necessitate enhanced breeding methods and outcomes. Progress in cacao breeding has been hindered by a long-generation cycle, limitations in land availability for large-scale breeding trials, and challenging abiotic and biotic stress factors, including several major diseases. Cacao tends to be outbreeding and cocoa production is often reduced by the incompatibility status of planting material and pollination inefficiency. The complex breeding mechanisms in cacao and difficulty in predicting the performance of promising selections as parents also pose challenges to breeders. Reciprocal recurrent selection schemes have been most successful to date. The advent of breeding with genomics and the unravelling of the cacao genome portend unprecedented advancements in cocoa breeding. This chapter explores the past, present and future prospects of cacao breeding, and describes how the use of traditional breeding allied with molecular and genomic approaches can empower cocoa breeders to meet the need for improved planting material with high productivity and yield efficiency, disease resistance, climate change adaptations, nutraceutical value and superior flavor and quality attributes.
