Comparative ontogenesis of Coffea arabica L. somatic embryos reveals the efficiency of regeneration modulated by the explant source and the embryogenesis pathway

• Published in: In vitro cellular & developmental biology. Plant Vol. 57; no. 5; pp. 796 - 810
• Main Authors: Ferrari, Ilse Fernanda, Marques, Giovanna Arcolini, Junior, Welington Luis Sachetti, Biazotti, Bárbara Bort, Pena Passos, Matheus, de Almeida, Julieta Andrea Silva, Mondego, Jorge Maurício Costa, Mayer, Juliana Lischka Sampaio
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-10-2021; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Cell Biology; Cell cycle; Cell division; Coffea arabica; Coffee; Cultivars; Cytoplasm; Developmental Biology; Embryonic growth stage; Embryos; Explants; Genetic engineering; Humidity; Leaves; Life Sciences; Micropropagation; Multiplication; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Plant Sciences; Plants; Regeneration; Somatic embryogenesis; Callus; Pro-embryogenic mass; Micropropagation; Plant growth regulators; Anatomy
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1007/s11627-021-10200-5

In vitro
micropropagation is an important technique for coffee multiplication performed by somatic embryogenesis, which can be indirect, with the formation of calluses, or direct, when embryos are formed directly from explant cells. In the present study, we characterized the ontogenesis of somatic embryos regenerated via indirect and direct somatic embryogenesis in leaf explants from
Coffea arabica
‘Mundo Novo’ and assessed the development of these embryos in leaf explants from adult plants maintained
ex situ
and
in vitro
. Anatomical analyses showed that leaf explants present structural differences depending on their origin. In the direct pathway, tissue develops more rapidly in explants from
in vitro
plants than in those from
ex situ
explants. In both methods, the formation of a pro-embryogenic mass was found to be essential for embryo formation. In the indirect pathway, calluses from
ex situ
material presented elongated cells and a loose external appearance. Conversely, calluses from
in vitro
material presented large regions of meristematic cells with a single large nucleus and dense cytoplasm. We propose that indirect somatic embryogenesis in
in vitro
–grown explants may accelerate genetic breeding in coffee, and it represents the most efficient condition for somatic embryogenesis, producing embryos in less time than the required by
ex situ
plants (indirect: 260 d in
ex situ
conditions, 62 d
in vitro
; direct: 270 d
ex situ
, 86 d
in vitro
).