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Plant
regeneration from immature embryos of
Kenyan maize inbred lines and their respective single cross hybrids through
somatic embryogenesis
Binott, J. J.1,2*,
Songa, J. M.1,
Ininda, J.1,
Njagi, E. M.2 and
Machuka, J.2
1Kenya
Agricultural Research Institute, Biotechnology Centre NARL
P.O. Box 14733-00800, Nairobi, Kenya.
2Department of Biochemistry
and Biotechnology, Kenyatta University, P.O. Box
43844-00100, Nairobi, Kenya.
*Corresponding author. E-mail:
jaynebinott@yahoo.co.uk. Tel: +254 4444137, +254
722-795312. Fax: +254 20 4444144.
Abbreviations:
TH, hybrid; TL, inbredline; DAP, days after pollination;
2,4-D dichlorophenoacetic acid.
Accepted 15 February, 2008 |
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Field grown,
self
pollinated maize
genotypes were planted in
KARI
(Kiboko and
Kabete)
research stations
between
January 2004
and May 2005.
Immature
maize embryos from twelve
parental inbred lines and their respective single cross
hybrids were evaluated for their ability form
callus, somatic
embryos and
subsequent regeneration into plants. The embryos
were excised from
surface sterilized kernels harvested at different
physiological stages, namely 10 - 24 days after pollination (DAP). They were used as
explants to initiate callus on solid N6 basal media with
varying level of
2,4-D (0 - 20 mg L-1) and
regenerated on hormone free MS media. Optimal
induction of primary callus at 2 mg L-1
averaged 83% and 67 in hybrids and inbred lines
respectively. Somatic embryo competence
was demonstrated in 6 inbreeds and 4 hybrids. However, plant
regeneration was only achieved in 4 inbreeds and 3 hybrids.
90% percent of regenerants were normal and fertile. The
successful regeneration of some
of the inbred lines and/or hybrids provides a basis for
development of
genetic transformation
using Agrobacterium tumefaciens to improve
priority traits such as enhanced insects/pest and drought
tolerance.
Key words:
Inbred lines and hybrids, immature
embryos, in
vitro plant regeneration, recalcitrancy. |
