Calli induction in leaf explants of coffee elite genotypes/ Inducao de calos em explantes foliares de clones elite de cafe

• Published in: Ciência rural 2011-03, Vol.41 (3), p.384-389
• Main Authors: de Rezende, Juliana Costa, de Carvalho, Carlos Henrique Siqueira, Pasqual, Moacir, Santos, Ana Carolina Ramia, de Carvalho, Stephan Malfitano
• Format: Article
• Language: eng ; spa
• Subjects: Cloning; Coffea arabica; culture medium; growth regulators; meios de cultura; reguladores de crescimento; Restaurants
• ISSN: 0103-8478; 1678-4596
• DOI: 10.1590/S0103-84782011000300004

Three experiments were carried out with the objective of achieving high effectiveness in calli induction from high heterozygosis leaf explants of Coffea arabica through indirect somatic embryogenesis. A randomized-block design in a 2x5 factorial arrangement made up of two media [BOXTEL & BERTHOULY (1996) and TEIXEIRA et al. (2004)] and five C. arabica genotypes were used in the first experiment. In the second experiment the embryogenic calli production potential was evaluated in ten genotypes. Each of them was considered as a treatment. In the third experiment the variations in both 2.4-D (2.5 e 20µM) and 2-iP (2.5 e 20 µM) concentrations in TEIXEIRA et al. (2004) medium and secondary media were evaluated. Crops were kept in a growth room under darkness, at 25±2°C. The medium described by TEIXEIRA et al (2004) was found to be superior when compared to that described by BOXTEL & BERTHOULY (1996) in the 2.2 and 7.2 genotypes. An opposite behavior was noticed in 4.2 genotype, that is, BOXTEL & BERTHOULY (1996) had medium superiority. Both 3.0 and 5.0 genotypes had the same behavior in both media studied, which shows that the somatic embryo production depends on the genotype. Calli induction depends on the 2-iP and 2.4 D ratio. The 20.0µM of 2.4-D and 20.0µM of 2-iP combination caused the highest embryogenic calli induction rate. Key words: Coffea arabica, culture medium, growth regulators. RESUMO Visando a alcancar alta eficiencia na inducao de calos a partir de explantes foliares de plantas matrizes de C. arabica com alta heterozigose, por meio da embriogenese somatica indireta, foram instalados tres experimentos. O primeiro experimento foi conduzido em esquema fatorial 2x5, constituido de dois meios de cultura (BOXTEL & BERTHOULY, 1996 e TEIXEIRA et al., 2004) e cinco genotipos de C. arabica. No segundo experimento, foi avaliado o potencial de producao de calos embriogenicos em 1 0 genotipos, sendo cada genotipo considerado como um tratamento e, no terceiro experimento, foram avaliadas as variacoes nas concentracoes de 2.4-D (2,5 e 20µM) e 2-iP (2,5 e 20µM) nos meios primario e secundario de TEIXEIRA et al. (2004). As culturas foram mantidas a 25oC, sob obscuridade. Para os genotipos 2.2 e 7.2, verificouse a superioridade do meio de cultura Teixeira et al. (2004) em relacao ao meio BOXTEL & BERTHOULY (1996). No genotipo 4.2, observou-se o comportamento inverso, ou seja, a superioridade do meio BOXTEL & BERTHOULY (1996). Os genotipos 3.0 e 5.0 apresentaram o