Cultivo in vitro e estaquia de Ginkgo biloba L.

Abstract

Ginkgo biloba is an ornamental specie originated from China and has called scientific attention in the west due to the production of chemical compounds as ginkgolides and bilobalide, useful in the treatment of various diseases. The dioecious, the dormancy of the seeds out of their original habitat and the low number of samples available in Brazil, are the limitative factors that justify the development of techniques like the tissue culture and cutting for its multiplication. Aiming to study the behavior of Ginkgo biloba during the in vitro culture and cutting it were carried out five experiments being evaluated the morphogenesis responses and the development of shoot-tips and nodal segments cultured in different culture media; as well the potential rooting of semi hardwood cuttings using different concentrations of growth regulator IBA (indolbutyric acid).It was not possible to establish the in vitro culture from nodal segments due to high rate of fungi contamination. The shoot-tips cultivated on media MS (MURASHIGE and SKOOG,1962)and WPM (LLOYD and McCOWN, 1980) without growth regulator presented the development of shoots from pre-existing shoot-tips, and the MS medium induced higher frequency of shooting and larger number of leaves/explant. Culture media supplemented with the benzilanimopurine (BAP 0, 0.5 1.0 and 2.0 mg L-1 ), kinetin (KIN 0 and 1.0 mg L-1), naftalenoacetic acid (NAA 0 and 0.1 mg L-1), indolacetic acid (IAA 0 and 1.0 mg L-1) and giberelic acid (GA3 0 and 0.5 mg L-1) growth regulators, combined or not with the nutritional addicts, promoted the induction of organogenic callus in 100 % of the shoot-tips cultured. The frequency of organogenic calli, as well the survival of them, were influenced by the composition of the medium, and the combination of KIN+AIA +L-proline+casein hydrolyzed was positive to the induction of this type of callus. In the experiment made with cuttings, the rooting obtained in the 3 doses of IBA tested was 2,5 %