CHARACTERIZATION OF THE MORPHOLOGICAL EVENTS IN THE DIRECT SOMATIC EMBRYOGENESIS OF Coffea arabica L. GENOTYPE LEAF EXPLANTS
JULIETA ANDRÉA SILVA DE ALMEIDA *
Centro de Café ‘Alcides Carvalho’, Instituto Agronômico de Campinas, Campinas, São Paulo, Brazil
REBECA ROCHA LEAL
Centro de Café ‘Alcides Carvalho’, Instituto Agronômico de Campinas, Campinas, São Paulo, Brazil
VALÉRIA CRISTINA BARBOSA CARMAZINI
Centro de Café ‘Alcides Carvalho’, Instituto Agronômico de Campinas, Campinas, São Paulo, Brazil
MARCUS VINICIUS SALOMON
Departamento de Extensão Rural, Coordenadoria de Assistência Técnica Integral, Campinas, São Paulo, Brazil
OLIVEIRO GUERREIRO-FILHO
Centro de Café ‘Alcides Carvalho’, Instituto Agronômico de Campinas, Campinas, São Paulo, Brazil
*Author to whom correspondence should be addressed.
Abstract
The vegetative multiplication of Coffea genotypes can be obtained by direct somatic embryogenesis. However, little is still known regarding the occurrence of this process in C. arabica. The objective of this study was to characterize the events during the formation of somatic embryos of this species by direct somatic embryogenesis. For this purpose, foliar explants from three genotypes were inoculated into a culture medium with ½ the concentration of MS salts, plus the addition of 10 µM 2-Isopentenyladenine, and maintained in the dark at 30°C. A sequence of morphological events was observed leading to the formation of somatic embryos. First, the explants formed rounded structures on their edges starting from 15 days after inoculation in the culture medium. Following this, the event of oxidation occurred simultaneously in the foliar explants and in the structures formed, starting from 60 days of cultivation. The last event was the initiation of somatic embryos, which started 90 days after inoculation. All the events occurred in a single culture medium.
Keywords: Rounded structure, oxidation, somatic embryos