Browsing by Author "Flegmann, A.W."

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The effect of thidiazuron on axillary shoot proliferation of Hevea brasiliensis in vitro
(Rubber Research Institute of Sri Lanka. Agalawatte, 1996) Senaviratne, P.; Flegmann, A.W.
Multiple axillary shoot production with a shoot doubling time of 26 days was obtained from nodal explants of juvenile orgin Hevea brasiliensis on a medium containing thidiazuron (N-phenyl- N'1,2,3-thidiazol-5ylyrea) at 0.02 ppm in combination with NAA at 0.2 ppm. The clusters of axillary buds produced in the presence of thidiazuron were subcultured at 4-week intervals while subdividing into two to four small propagules depending on the size of the cluster. Axillary buds showed a satisfactory elongation on their transfer onto a growth regulator-free medium. Elongated axillary shoots which were more than 100 mm in hight produced roots in the presence of IBA at 2 ppm.
The effects of the basic medium and the carbohydrate content on shoot cultures of Hevea brasiliensis
(Rubber Research Institute. Agalawatte, 1996) Seneviratne, P.; Flegmann, A.W.; Wijesekera, G.A.S.
Woody Plants Medium (WPM) was superior to murashige and skoog medium (M S), which showed better axillary bud growth of both juvenile and mature shoot materials. The effect was more pronounced in later passages, in particular, on the survival rate of the cultures. Most of the cultures grown on M S medium did not survive more than 24-28 weeks, while on WPM medium cultures survived for more than one and a half years, until the experiment was terminated. The level of sucrose in the medium also had an effect on the growth of the primary axillary shoots, specially the length and the leaf growth. The length of primary axillary shoots incresed with the increasing levels of sucrose in the medium up to 10 per cent with clonal materials. Explants did not survive beyond 8 weeks when the medium was not supplied with sucrose.
The positional effect of the explant on In vitro growth of axillary buds of Hevea brasiliensis
(Rubber Research Institute. Agalawatte, 1996) Senaviratne, P.; Flegmann, A.W.; Wijesekera, G.A.S.
Apart from the high apical dominance showed in shoot explants of hevea, the location of the node in the shoot, seems to play a vital role in in vitro axillary bud proliferation. Better performance was observed when the axillary buds harvested as nodes, were not too close and also not too far from the apex as measured by the primary axillary shoot growth. This was true for both juvenile and mature arigin materials. Furthermore, "active" nodes were superior to "dormant" nodes.
The problem of surface sterilization of shoot materials of Hevea
(Rubber Research Institute of Sri Lanka. Agalawatte, 1995) Seneviratne, P.; Flegmann, A.W.; Wijesekera, G.A.S.