SummaryPatterns of shoot growth and branching were studied over two growing seasons in rooted cuttings collected from both epicomric shoots and seedlings of Betula pendula Roth. Epicormic shoots were induced to sprout on stumps and small logs of 5-, IO-and 30.year-old trees. The use of epicormic shoots enhanced the rooting capacity of stem cuttings collected from these shoots but did not appear to reverse the process of maturation.In this study, maturation was based on characteristics typical of mature trees but not necessarily those of the mother plant, because it was not possible to root cuttings, for comparison, from 5-, lo-and 30-year-old ortets, other than from epicormic shoots. There was evidence of the persistence of mature characteristics through an increase in shoot plagiotropism with increasing ortet age. Rooted cuttings from both seedlings and epicormic shoots, however, assumed an increasingly orthotropic habit with a smaller shoot angle at the end of the first growing season than at the beginning and this continued into the second growing season. Other indications of maturation, such as delayed bud flushing and the incidence of flowering with increasing ortet age, were also evident in rooted cuttings from epicormic shoots. There was a clear difference in branching habit depending on cutting source. Rooted cuttings derived from epicormic shoots produced nearly twice as many lateral branches compared with rooted cuttings collected from seedlings, but this was not an effect of maturation. There was some evidence that rooted cuttings derived from seedlings grew taller than rooted cuttings from epicormic shoots.

Vernonia amygdalina is a plant with great medicinal potentials due to the phytochemicals it possesses. The establishment of axenic culture and callus induction are important as the primary steps to acquire callus and cell suspension cultures which are prospective to be used as alternatives in the production of phytochemicals. The effect of different regimes of sterilization unveiled that explants treated with mercuric chloride showed significant difference in the mean number of axenic explants, but observations of serious necrosis in all explants that later lead to death were recorded. Whilst, the explants treated with Clorox® were not significantly difference in the mean number of axenic explants but the explants obtained were healthy and the growth was sustained. For callus induction, there was no significant difference in the callus induction frequency (CIF) among different concentrations of 2,4-D or picloram. In conclusions, the explants were recommended to be surface sterilized with 15% of Clorox® for 15 minutes as it was more economical and less time consuming. Whereas, MS media supplemented with 0.5 mg/L 2,4-D or 0.5 mg/L picloram would be a better choice for callus induction due to observation of root formation at lower concentrations of 2,4-D.

Ananas comosus L. Merr. (Morris) commonly known as pineapple, is an economically important fruit in Malaysia. Among the pineapple producers in the world, Malaysia has put massive efforts to fulfill the high domestic and global market demand. Several attempts have been made recently by integrating biotechnology in conventional breeding concerning issues on the shortage production of pineapple fruits. The fruit productivity could be enhanced via a tissue culture system as it might provide the good quality of planting materials in industrial scale throughout the years. Hence, this study was designed to assess the effectiveness of utilizing tissue culture technique to produce sufficient plantlets of pineapple. The procedure involved culturing aseptic axillary buds excised from suckers in treatments with various concentrations of 6-benzylamino purine (BAP) to induce shoot multiplication. The suckers were successfully disinfected by soaking in 100% Clorox for 3 min with 80% survival and free contamination. The best result for this experiment was obtained in MS supplemented with 3.0 mg L -1 BAP, produced the highest no. of shoots per explant with the highest no. of leaves per explant. Besides, it was found that the treatments added with more than 3.0 mg L -1 BAP decreased the number of shoots and leaves per explant. Nevertheless, further advance study especially in quality control should be done to verify the quality of fruits meet the standard for commercialization.