Embriogênese somática a partir de folhas imaturas e flores desenvolvidas in vitro de dendezeiro (Elaeis guineensis Jacq)

• Autor(a) principal: Carvalho, Mychelle
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1131
• topic: Embriogênese somática; Elaeis guineensis; Anatomia; Somatic embryogenesis; Elaeis guineensis; Anatomy; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

The study aimed to establish an efficient protocol for somatic embryogenesis of the oil palm, especially all of cultivars explored in Brazil, as well as to acomplish the anatomical caracterization of the embryogenic process. For induction of somatic embryogenesis we used two explants types, leaves segments and female inflorescences, resulting in two experiments. In the first experiment, sections of the 5 mm in immature leaves from two oil palm genotypes (G1001 e G2301) of 1,5 years of age were inoculated in culture medium Y3 (Eeuwens, 1978) supplemented with 0.3% activated charcoal and 2,4-D at four concentrations (800, 1000, 1200 and 1400 µM). Higher percentage of callus induction was obtained in G2301 leaf explants submitted to the concentration 800 µM of 2,4-D. The obtaining of pro-embryogenic masses starting of the calli occurred in medium supplemented with 9 µM 2,4-D added to 1000 µM putrescine or 100 µM spermine. A higher percentage of regeneration of somatic embryos occurred from pro-embryogenic masses that were pre-conditioned and inoculated on regeneration medium supplemented with 0.045 µM 2,4-D and 1000 µM putrescine. The somatic embryos regenerated exhibited characteristic protoderm, procambium strands and shoot meristem and germinated in culture medium Y3 added 0.54 µM ANA and 1000 µM putrescine. The seedlings showed simultaneous development of shoot and root and 70.4% of plants could be successfully acclimatized. In the second experiment, rachillas taken from immature female inflorescences in two developmental stages were inoculated in different culture media (MS and Y3), the supplemented with 475 µM of different auxins (Picloram and 2,4-D) and 0.3% activated charcoal . The development of flowers occurred after 120 days of inoculation in vitro, depending on the developmental stage of the inflorescence and the growing medium. The flowers formed in Y3 culture medium were detached from rachillas and inoculated in the same culture medium with reduced auxin concentrations for 9 µM being combined or not with 1000 µM of putrescine. After 60 days, greater callus formation occurred in flowers grown in medium supplemented with 9 µM Picloram combined with 1000 µM of putrescine. The regeneration of somatic embryos occurred after reduction at 100 times the concentration of auxin in the culture medium, maintaining the same concentration of putrescine. Embryos showed protoderm well defined, delimiting a homogeneous mass of cells corresponding to the ground meristem, interspersed with well-defined procambium strands. By means of histological analysis it was found that the formation occurred from the perivascular regions in the gynoecium and embryo formation occurred from the regions of meristematic callus, following the multicellular pattern.