Tissue culture for propagation of Dalbergia melanoxylon is a mandatory stepy to be taken
The first attempt on D. melanoxylon tissue culture was conducted from 2010 to 2013 at a high level
of expectations. A total of 500 seeds were sterilized at different concentration of reagents and inoculated
at different strength of the Murashige and Skoog medium for germination to obtain disease
free explants for callus induction trials. A total of 400 nodal segments obtained from germinated
seeds were sterilized at different concentration of reagents and inoculated at different
hormonal combinations to induce callus formation for seedling multiplication. Results from this
tissue culture attempt set a foundation for tissue culture success in D. melanoxylon on the future
research. Only 19.8% of seeds inoculated in half strength of Murashige and Skoog medium germinated
within 7 days while only 6.8% of seeds inoculated in full strength of Murashige and Skoog
medium germinated within 6 days. This germination was at sterilization of 20 minutes in 35%
ethanol and 20 minutes in 2.6% sodium hypochlorite. A total of 1% of inoculated D. melanoxylon
seedling fragments in Murashige and Skoog media supplemented with hormone combination at
2.0 mg/l BAP + 0.5 mg/l NAA developed callus after16 days from the inoculation day. The final
weight of the callus at the last record was 0.62 g. In this induction ex-plants were surface sterilized
in 35% ethanol for 20 minutes and 2.6% sodium hypochlorite solution for 20 minutes. The color
of callus was green and friable in nature. Other hormonal combinations in this case did not induce
callus production. These results suggested that the problems which affect seed germination in the
natural environment are also reflected on germination in the Murashige and Skoog medium and in
callus induction. Vulnerability to fungal attack is a limitation for successful callus induction and
germination in the culture room. More research under improved sterile conditions is needed to
improve callus percentage for seedling multiplication.
Mkwawa University College of Education