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Effect of temperature,
light intensity and growth regulators on propagation of
Ansellia Africana from cuttings
Alpheus Mpilo Zobolo
Department
of Botany, University of Zululand, Private BagX1001
Kwadlangezwa 3886, South Africa. E-mail:
azobolo@pan.uzulu.ac.za.
Abbreviations: CLI,
Mature cuttings with green leaves and an inflorescence;
CL, young cuttings with leaves and no inflorescence;
C, mature leafless cuttings with an inflorescence.
Accepted 18
June, 2010 |
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Ansellia
africana
(Orchidaceae) is an important endangered medicinal plant
species of South Africa which has been heavily exploited in
recent years. Experiments were conducted in growth rooms at
different temperatures (16, 26, 36°C) and in a nursery at
different light intensities induced by shade cloth densities
(200, 400, 600, 800 μmol m-2 s-1
light) at the University of Zululand, South Africa. Mature
A. africana plants were cut into two lengths, the top
leafy shoot and the bottom part with roots (10 – 15 cm in
length, 3 - 8 mm diameter). The top leafy or leafless
cuttings were used in all the experiments. Bud formation and
rooting competence of cuttings were compared by growing
cuttings treated with solutions of varying
naphthaleneacetic acid
(NAA) and kinetin concentrations in river sand. Three types
of cuttings were used: a) mature cuttings with both green
leaves and an inflorescence, b) mature cuttings with yellow
leaves (or leafless) and an inflorescence, and c) young
cuttings with green leaves but no inflorescence. The lowest
percentage death was recorded in cuttings with both green
leaves and an inflorescence in the growth room (10%) and
nursery (5%), respectively. The same type of cuttings gave
significantly higher (P < 0.05) percentage bud formation in
the incubator (18%) and nursery (37%), respectively. NAA was
effective in root initiation when applied after bud break.
The best results for root number, root length and root dry
weight were achieved at NAA concentration of 1 or 2 mg l-1.
Optimum conditions for bud formation were temperature of
36°C, light intensity of 200 - 400 μmol m-2 s-1
and kinetin concentration of 1 or 2 mg l-1. A
maximum value of 57% was recorded for bud formation in this
study.
Key
words:
Ansellia Africana, cuttings, kinetin,
naphthaleneacetic acid,
propagation. |
