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CBN-V Video Archives - S7-18
Cassava Starch as Alternative to Agar for Gelling Tissue Culture
Media
Mbanaso, E.N.A.1,
J. Crouch2, F.A. Onofeghara3 and M. Pillay2
1 National Root Crops Research Institute, Umudike, Umuahia, Nigeria
ephta@infoweb.abs.net
2 Formerly of the Department of Plant Science and Biotechnology,
University of Port Harcourt, Port Harcourt, Nigeria
3 Formerly of International Institute for Tropical Agriculture, Onne,
Nigeria
Cassava starch was used to gel tissue culture media for in vitro
multiplication and regeneration of Musa genotypes. Even
gelation was achieved by the incorporation of starch as a thick
slurry into pre-heated medium prior to autoclaving. Solidity of
medium increased with increase in starch concentration. Drop in
post-autoclave pH in starch-gelled medium exceeded 4 units compared
to agar. Reasonable stability in pH was observed for up to 7 days.
Cassava starch at 60 and 70 gl–1 gave adequate support and
orientation to Musa shoot tip explants. After 4 weeks in
culture, survival rates in shoot tips seeded in 70 g–1 cassava
starch medium (91 %) exceeded that in 5 g–1 agar-gelled medium (72
%) although the difference was not significant. A similar pattern
was also observed for shoot proliferation. Shoot tip proliferation
in cassava starch gelled medium was as consistent as in agar-gelled
medium in at least four levels of subculture. Plant regeneration,
root formation and ex vitro establishment was monitored in
shoots cultured in medium gelled in 30, 40, and 50 gl–1 cassava
starch compared to 5 gl–1 agar. Mortality in vitro was low in
30 gl–1 cassava starch and compared favourably with the mortality
observed in g–1 agar. Regenerants did not differ significantly in
root production and ex vitro establishment. Cassava starch
was, therefore, considered suitable as a gelling agent at 30 gl–1 in
Musa culture media. Cassava starch could be a cheaper
alternative to agar in developing countries needing to import agar
whereas cassava is ubiquitous.
2007©
Donald Danforth Plant Science Center All rights reserved.
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