Micropropagation and acclimatization of Bauhinia cheilantha (an important medicinal plant)

The objective of this study is to establish a micropropagation protocol for Bauhinia cheilantha. This was undertaken through an evaluation of 6-benzylaminopurine (BAP) effects, alone or in combination with a-napthaleneacetic acid (NAA), on the morphogenesis of different explants, taken from 20 day old seedlings grown in vitro. In the rooting, different auxins, indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and NAA were tested under the influence of activated charcoal. The nodal segments showed an organogenic capacity which is 2.4 times greater than the cotyledonary segment. The highest number of shoots (2.84) was obtained at 2.0 mgl-1 BAP. The use of 0.5 mgl-1 IAA, 1.0 mgl-1 NAA or 0.25 mgl-1 IBA gave the highest percentage of rooting (about 65.0%). Concerning the activated charcoal (AC), there was a beneficial effect in most of the analyzed characteristics at a concentration of 0.5 gl-1. The culture tube, with forced ventilation during rooting, increased the percentage of seedling survival during the acclimatization in greenhouse. This finding reveals that it is possible to obtain in vitro culture of B. cheilantha using the segment nodal as a source of explants in woody plant medium (WPM) supplemented with BAP.Key words: Bauhinia cheilantha, woody, in vitro culture, organogenesis, seedling node, activated charcoal

Use of multivariate analysis to evaluate the effect of sucrose on in vitro cassava conservation

The aim of this work was to evaluate the effect of sucrose to reduce the in vitro growth of cassava plants using multivariate statistical tests. Cassava conservation has a relevant role as an auxiliary strategy for preservation and genetic breeding. Micro-cuttings of cassava accessions BGM 264, BGM 265, BGM 1037 and BGM 1282 from the Active Germplasm Bank of the Embrapa Cassava and Fruits were tested with five different concentrations of sucrose (0, 14.6, 29.2, 43.8, 58.5 mM) and the following variables were evaluated: plant height (cm), total number of leaves, number of senescent leaves, number of micro-cuttings, size of callus, number of roots and plant vigor. The data were submitted to analysis of variance (ANOVA) and multivariate analysis of variance (MANOVA). According to the criterion of Singh, the variable that contributed most to explain the behavior of cassava plants under the conditions studied was the number of leaves, with 36.52%, while the vigor of the plants showed the lowest contribution (0.66 %). The best concentration for in vitro cassava conservation was 58.45 mM of sucrose, based on the number of viable plants after incubation.Key words: Biotechnology, germplasm conservation, tissue culture, Manihot esculenta, genetic resource