Seed germination and in
vitro regeneration of the African medicinal and
pesticidal plant, Bobgunnia madagascariensis
Blackson L. K. Thokozani1,
Donald Zulu2, Gudeta W. Sileshi3*,
Zewge Teklehaimanot4, Dominic S. B. Gondwe2,
Viswambharan Sarasan5 and Philip Stevenson5
University, P/Bag 201, Luwinga, Mzuzu 2, Malawi.
Agricultural Training Centre, Kasisi, P. O. Box 30652,
Agroforestry Centre (ICRAF), Southern Africa Programme,
Chitedze Agricultural Research Station, P.O. Box 30798,
of Environment and Natural Resources, Bangor University,
Bangor, LL57 2UW, United Kingdom.
Botanic Gardens, Kew, Surrey, TW9 3DS, United Kingdom.
*Corresponding author. E-mail:
firstname.lastname@example.org. Tel: +265-999-642-149 or
+265999642149. Fax: +265-1-707-319.
Accepted 6 April, 2011
Propagation of the medicinal and pesticidal tree,
Bobgunnia madagascarensis is difficult due to poor and
erratic germination of its seeds and slow growth of its
seedlings. This study involved two separate experiments. The
first evaluated the effect of pre-sowing treatments and
growing medium on ex vitro seed germination and early
seedling development. The second experiment involved in
vitro germination, shoot initiation and rooting of
shoots. Pre-sowing seed treatments involved soaking seeds in
cold and hot water for 12 and 24 h and soaking in different
concentrations (0, 100, 200, 400 and 800 mg/l) of
gibberellic acid for 24 h. Soaking of seeds in cold or hot
water for up to 24 h did not achieve more than 45%
germination, while seeds treated with gibberellic acid
achieved <20% germination rates. On the other hand, in
vitro procedures achieved 30 to 70% germination of
seeds. Seedling survival of ex-vitro germinated seeds
was higher (>76%) when seeds were sown in a growing medium
without compost compared with a medium with compost (<43%).
All shoot-tips isolated from the in vitro germinated
seedlings on B5 media without plant growth regulators
continued to grow as a single shoot, while shoot-tips
cultured on B5 supplemented with 0.1 mg/l of
naphthaleneacetic acid (NAA) and thidiazuron (TDZ) produced
two shoots each after four weeks. It was concluded that
B. madagascariensis seeds had very low ex vitro
germination percentages. Although, in vitro cultures
improved seed germination, axillary shoot multiplication and
rooting were not satisfactory. Therefore, further
studies are needed to develop an optimal in vitro
multiplication protocol for B. madagascariensis.
Axillary shoot multiplication, gibberellic acid, in vitro
regeneration, seed germination, Swartzia.