Embryoid formation in callus tissues of coffee.
01 Aug 1970-Vol. 19, Iss: 4, pp 509-514
TL;DR: In callus tissues of one species, i.e. Coffea canephora Pierre ex Froehner (‘Robusta’ coffee), embryoid and plantlet formation was observed.
Abstract: SUMMARY
The isolation and subculturing of callus tissues from three coffee species is described. In callus tissues of one species, i.e. Coffea canephora Pierre ex Froehner (‘Robusta’ coffee), embryoid and plantlet formation was observed.
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20 Apr 2011
235 citations
TL;DR: At concentrations between 30–60 μM, AgNO3 improved embryo yield for the genotypes evaluated, while higher doses negatively affected the regenerative capacity, and the substitution of maltose, glucose or fructose for sucrose produced different responses depending on the genotype.
Abstract: The response of five Coffea canephora Pierre genotypes with regard to somatic embryogenesis was tested on media containing silver nitrate (AgNO3) and different carbohydrates (sucrose, fructose, maltose and glucose). The presence of AgNO3 caused only small modifications to the ionic equilibrium of the media. At concentrations between 30–60 μM, AgNO3 improved embryo yield for the genotypes evaluated, while higher doses negatively affected the regenerative capacity. The substitution of maltose, glucose or fructose for sucrose produced different responses depending on the genotype. Fructose significantly increased somatic embryo production in genotypes N91 and N128, while maltose was highly effective for N75. In addition, more synchronous embryo development was observed in genotype N91 when glucose was used instead of sucrose.
169 citations
Cites background from "Embryoid formation in callus tissue..."
...In coffee, somatic embryogenesis has been reported since 1970 (Staritsky, 1970) and constitutes a model system for perennial species (Sondahl and Loh, 1988)....
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TL;DR: High frequency somatic embryo induction and subsequent plantlet development are reported for the first time in cultures of Coffea arabica leaf tissue expiants and between 50–60% of the replicate cultures contained tissues with HFSE.
140 citations
TL;DR: In this article, the authors performed histocytological analysis on leaf explants of Coffea arabica undergoing somatic embryogenesis and showed that the entire region surrounding the edge of the explants showed the differentiation of organized structures with little or no callusing.
Abstract: Histocytological analysis carried out on leaf explants of Coffea arabica undergoing somatic embryogenesis revealed that, using a culture method involving a single Gelrite-containing semisolid medium, the entire region surrounding the edge of the plant-derived leaf explants showed the differentiation of organized structures with little or no callusing. Histological examination of embryogenesis without callus formation (direct somatic embryogenesis) revealed that at approximately 1 week after the explant had been placed in culture, the development of the embryo began in the form of a small, isodiametric, densely cytoplasmic cell that underwent a series of organized divisions. In embryogenesis from callus (indirect somatic embryogenesis), however, the embryogenic cell was observed within the first week. Our histological observations indicate that both direct and indirect somatic embryos of coffee that form on explanted leaf segments and callus, respectively, have a unicellular origin.
138 citations
TL;DR: An improved procedure for the induction, proliferation and regeneration of embryogenic callus from coffee leaf explants has been developed and yielded so-called “high frequency” embryogenicCallus ofCoffea canephora P. ex Fr.
Abstract: An improved procedure for the induction, proliferation and regeneration of embryogenic callus from coffee leaf explants has been developed. The optimal culture conditions for callus induction and somatic embryogenesis yielded so-called “high frequency” embryogenic callus ofCoffea canephora P. ex Fr., Arabusta and Congusta, more rapidly and abundantly than other published procedures.Coffea arabica L. genotypes, however, were less responsive to the procedure. The highest multiplication rate of embryogenic callus in liquid culture, which avoided the differentiation of embryos, was obtained by culture at an inoculum density of 10 g callus 1-1 in a modified MS medium containing 4.5 μM 2,4-dichlorophenoxyacetic acid, under 3 μmol m-2 s-1 illumination, and subcultured every 7–10 days. The best long-term maintenance of embryogenic potential was obtained by culture of aggregates (250–1000 μm in diameter) at an inoculum density of 5 g 1-1, with medium renewed every 3–4 weeks. Under these conditions, embryogenic potential ofC. canephora callus was maintained for over 2 years. Analysis of nutrients absorbed by the callus cultures demonstrated that half strength MS macro- and micro-salts were not depleted during at least 3 weeks of sustained culture. The highest regeneration of embryogenic callus required the omission of 2,4-D and a reduced culture density of 1 g 1-1. Under these conditions of culture, 1 g ofC. canephora or Arabusta callus produced 1.2 and 0.9×105 somatic embryos, respectively, after 8–10 weeks in liquid regeneration medium. This was an overall reduction of 4–6 months from explant to regenerant, when compared with other procedures.
129 citations
References
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3,534 citations
TL;DR: The production of embryoids and their subsequent development into complete plants in a culture of a monocotyledon, Asparagus officinalis L.
Abstract: SINCE Steward1 demonstrated the totipotency of plant cells the morphogenesis of plant tissues cultured in vitro has often been investigated. So far, embryoid formation has been found only in dicotyledons. We report here the production of embryoids and their subsequent development into complete plants in a culture of a monocotyledon, Asparagus officinalis L.
97 citations
TL;DR: Conditions which control either root or shoot formation in callus cultures of Populus tremuloides Michx are described.
Abstract: INITIATION of organs on cultured callus tissue has been reported for herbaceous species1,2, but similar reports for woody species have been meagre, and the results sporadic. The control of root rather than shoot initiation has been emphasized3–5. I describe here conditions which control either root or shoot formation in callus cultures of Populus tremuloides Michx.
87 citations
01 Dec 1969
TL;DR: Morphogenesis of floral buds excised at various stages of development was followed in vitro and the growth of callus and the differentiation of embryoids could be maintained through repeated subculturing.
Abstract: SUMMARY
Morphogenesis of floral buds excised at various stages of development was followed in vitro. The buds comprising the primordia of sepals and stamens (Stage I) failed to complete normal development on any of the nutrient media tried. However, the initiation and further development of carpels occurred even on a medium containing mineral elements, glycine, vitamins and sucrose. On the other hand, the buds having the anthers at the pollen mother cell stage (Stage II) completed microsporogenesis and 2-celled pollen grains were formed in the anthers. The torus i.e. the central dome bearing the carpels, of Stage II, and III (buds having anthers at pollen grain stage) elongated enormously and emerged through the folded sepals. Regeneration of roots and shoot buds (especially in Stage II & III buds) was common.
In addition, the floral buds of all stages formed callus which subsequently differentiated roots, shoot buds and embryoids leading to the formation of plantlets. The latter, in turn, developed embryoids from the epidermal and pith cells of the stem. On subculturing, the hypocotyl portion of the in vitro plantlet was capable of developing embryoids directly from the epidermal cells, whereas the radicular and plumular portions of the same plantlet first formed callus and subsequently embryoids.
The growth of callus and the differentiation of embryoids could be maintained through repeated subculturing. Embryoids could be induced even on a simple medium having only mineral elements and sucrose. Among the several growth adjuvants used, a combination of coconut milk and IAA supported best callus growth and normal embryoid differentiation.
28 citations