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Asymbiotic seed
germination and in vitro seedling development of
Epidendrum ibaguense Kunth. (Orchidaceae)
M. M. Hossain
Department
of Botany, University of Chittagong, Chittagong-4331,
Bangladesh.
E-mail:
musharof20bd@yahoo.com.
Accepted
28 August, 2008 |
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Effects of four asymbiotic media;
Murashige and Skoog (MS), Phytamax (Sigma, USA; PM), Mitra
et al.
(M) and
Knudson ‘C’ (KC) were evaluated for seed germination and
early protocorm development in Epidendrum ibaguense
Kunth. Besides, effects of peptone, activated charcoal and
plant growth regulators (6-benzylaminopurine (BAP) and
2,4-dichlorophenoxyacetic acid (2,4-D)) were also studied.
Maximum seed germination was achieved on M and PM (~90%)
fortified with 2 gl-1 peptone. Medium
supplemented with 1.0 mgl-1 BAP improved seed
germination in contrast to basal media whereas 2,4-D either
singly or in combination with BAP remarkably reduced the
germination rate. Activated charcoal in the medium enhanced
germination of seed, induced significantly large size
protocorms (1.63±18)
and early rooting in protocorms. Within two weeks of
culture, spherules emerged out due to cracking of the seed
coat. The spherules developed into protocorms with a leaf
primordium at apical portion after 3 to 4 weeks and
gradually produced complete seedlings. Strong and stout root
system was induced in in vitro seedlings on
transferring in half strength PM and M media fortified with
0.5-1.0 mgl-1 indole acetic acid (IAA).
Well-rooted seedlings were transferred to green house with
90% survival.
Key
words:
In vitro, seed germination, protocorm, Epidendrum
ibaguense, orchid. |
