<i>In vitro</i> propagation of <i>Caesalpinia spinosa</i> (Mol.) O. Kuntz from axillary buds of selected trees

Guarango or tara [Caesalpinia spinosa (Mol.) O. Kuntz] is a tree native to the Andes, with great economic importance and for reforestation programs. The aim of this work was to in vitro propagate this specie from axillary buds of selected trees. During in vitro establishment, the effect of sodium hypochlorite (3.0%) with different times of disinfection (5.0, 10, 15 min), as well as the effect of 6-BAP on the in vitro response of buds were studied. For multiplication, different combination of 6-BAP with 0.1 mg l-1 ANA were tested. A free-growth regulator culture medium was used for rooting. The best results for in vitro establishment were achieved with a disinfection treatment with sodium hypochlorite 3.0% for 10 minutes and cultivation in a culture medium with 0.25 mg l-1 6-BAP, which 90% of buds in vitro established, with a length of 6.71 cm. The highest multiplication rate of shoot (2.88 per explant) was obtained with 1.0 mg l-1 6-BAP and 0.1 mg l-1 ANA, after 60 days of culture. The 55% of these shoots developed roots in a half-strength basal salts MS culture medium free of regulators of growth.   Keywords: biodiversity, conservation, forest plant, guarango, tissue cultur

Somatic embryogenesis of the banana hybrid cultivar FHIA-18 (AAAB) in liquid medium and scaled-up in a bioreactor

The development of somatic embryos in liquid culture medium has a number of advantages for large-scale propagation of plants. This paper describes an improved system for the mass propagation via somatic embryogenesis of the banana hybrid cultivar FHIA-18 (AAAB). Explants from immature male flowers were used to form high frequency embryogenic tissue, this tissue was then used to establish embryogenic cell suspensions in a basic MS medium plus 1.0 mg 1 -1 biotin, 100 mg 1 -1 glutamine, 100 mg 1 -1 malt extract (Sigma), 1.0 mg 1 -1 2,4-D and 45 g 1 -1 sucrose. Secondary multiplication of somatic embryos was achieved in liquid media in rotary shaker and in bioreactors. The number of embryos per litre obtained with 80.0% DO 2 and effects of pH were also studied. A high regeneration percentage of plants were obtained (89.3%) in only 1 month of culture, somatic embryos were then placed to germinate in temporary immersion systems and field testing of somaclonal variation

The surface-active bio oil solution in sulfured copper mineral benefit

Surface-active bio-oil (SABO) solutions, prepared from vacuum pyrolysis bio-oil with a phenol-to-levoglucosan mass ratio of 4.8, was compared to pine-oil (PO) as foaming agent in the process of flotation of sulfured copper minerals. With the aid of 2³ factorial designs, regression models were obtained for % Cu in flotation concentrate (L Cu) and % Cu recovery (R), as functions of foaming agent-to-Cu mineral, collector-to-Cu mineral mass ratio and liquid-to-solid ratio (v/w). Experimental designs composed of a <IMG SRC="/img/revistas/bjce/v22n1/a01img01.gif">saturated design in its first half and a fold over <IMG SRC="/img/revistas/bjce/v22n1/a01img01.gif">design in its second half allowed to study the influence of flotation conditions on L Cu and R when SABO was the foaming agent. The factors selected were: particle size; pulp pH; flotation time; initial Cu content in the mineral (mineral type); liquid-to-solid ratio and finally SABO-to-mineral and collector-to-mineral mass ratio. Within the chosen experimental region only pulp pH affected significantly both responses. It is shown that high pulp pH, in the presence of minerals rich in Cu content leads to a significant increase in L Cu and R. Although SABO to mineral mass ratio is high compared to PO, it is considered that an optimization study on pulp pH should reduce this difference making SABO an attractive alternative to PO and a way to widen the field of applications of pyrolysis products