SOMATIC EMBRYOGENESIS AND MORPHOANATOMY OF Ocotea porosa SOMATIC EMBRYOS

Abstract

http://dx.doi.org/10.5902/1980509812343Ocotea porosa seeds have strong tegument dormancy, recalcitrant behavior, low and irregular germinationand that makes its natural propagation difficult. The aim of this study was to establish a protocol ofregeneration of Ocotea porosa from somatic embryogenesis. Immature embryonic axes were inoculatedon WPM culture medium supplemented with 2.4-D (200 μM) combined or not with hydrolyzed casein orglutamine (0.5 or 1 g l-1), during 90 days. The repetitive embryogenesis was induced on medium with 2.4-D(22.62 μM) combined with 2-iP (2.46 μM) followed by transfer to culture medium with hydrolyzed caseinor glutamine (1 g l-1) during 90 days. The maturation of somatic embryos was tested in culture mediumcontaining NAA (0.5 μM) and 2-iP (5; 10 and 20 μM). The highest percentage of somatic embryos induction(8.3%) was observed in WPM culture medium containing 200 μM 2.4-D and 1 g L-1 hydrolyzed casein andthe development of somatic embryos occurred indirectly. Repetitive somatic embryogenesis was promotedin WPM medium containing hydrolyzed casein or glutamine. However, the culture medium containinghydrolyzed casein promoted the maintenance of embryogenic capacity for more than two years. Duringthe maturity phase, there was a low progression of globular embryos to cordiform and torpedo stages.The different ontogenetic stages of somatic embryos of Ocotea porosa were characterized by histologicalstudies.

Keywords

• massa embriogênica
• caseína hidrolisada
• glutamina
• histologia