EmbriogÃnese somÃtica e isolamento de protoplastos de pequizeiro / Somatic embryogenesis and protoplast isolation of Caryocar brasiliense CAMB.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The Caryocar brasiliense is one of the native fruit species from Cerrado with higher economical, ecological and social importance. In the last decades, large land extensions in the â Cerrado â has been used for agricultural system. This fact associated with a natural low regeneration rate has caused the reduction in natural populations of the species. Based on these facts, it is important to optimize the propagation technique for seedling production in order to regulate the production of the species and use it to recover degraded areas. The objective of the present work was to study aspects of the in vitro cultivation of Caryocar brasiliense through calogenesis, organogenesis, somatic embryogenesis and isolation of protoplast. For the induction of somatic embryos and embryogenic calli, combinations of different concentrations of 2,4-D x sucrose and 2,4-D x 2- iP were tested. For embryo development, ABA was tested. For protoplast isolation, two enzymatic solutions, incubation time, manitol concentration and incubation system (stationary and orbital agitation) were tested. For the in vitro cultivation, combinations of BAP x ANA and cinetina x picloran were evaluated. It was also tested, the effect of the cultivation in liquid and solid medium in the absence or presence of light. The results demonstrated that embryos and embryogenic callus can be obtained with 45 days of cultivation as well as embryogenic callus in sub cultivation at 45 days in MS medium supplemented with 60 g L-1 sucrose. 18.32 x 105 Â1.18 protoplasts were obtained per gram of in vitro leaf tissue fresh mass with an average diameter of 25.19 Â4.75 μm. 96% of viable protoplasts were obtained using the enzymatic solution composed by 1% (p/v) Cellulase âOnozuca R-10â (Yakult Honsha) + 0.2% (p/v) âMacerozyme R10â (Yakult Honsha) + 0.1% (p/v) Driselase (Sigma London Chemical Co Ltda) + 5 mM MES in CPW medium and maintained in incubation for 10 hours in stationary system. The in vitro cultivation promoted the highest leaf number average (3.74), length average of the three largest shoots (94.5 mm), fresh mass (1.23 g) and dry mass (0.15 g) using cultivation in liquid medium. Leaves obtained in solid medium showed higher thickness. Shoots grown in the absence of light presented higher average length. Higher number and size of shoot (13.3 and 22.94 mm) were obtained with 0/1; 0/0.5 NAA/BAP, respectively. Higher number and higher root size (28.07 and 29.07 mm) were obtained with 1/0 mg L-1 NAA/BAP. Guidance committee: Renato Paiva, PhD (Adviser); Dra. PatrÃcia Duarte de Oliveira Paiva (Co-adviser); Dr. Breno Regis Santos (Co-adviser).

ASSUNTO(S)

fisiologia vegetal protoplastos caryocar brasiliense. embriogÃnese somÃtica somatic embryogenesis tissue culture protoplast cerrado caryocar brasiliense cerrado cultura de tecidos

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