Abstract:
This experiment was carried to study the
in vitro shoot response of
cotyledonary nodal explants derived from 12 days old in vitro grown
seedlings of tomato cultivar KC 1. A centimeter long cotyledonary nodal
explants were excised carefully from in vitro raised seedlings and cultured
on MS media with 0.5 1.0 mg/l kinetin and 1.0 0.5 mg/l IAA or with 0.2
1.0 mg/l BAP and 1.0 0.2 mg/l NAA. After 4 weeks of culture, they were
sub cultured on MS medium containing 2.0 mg/l BAP and 0.2 mg/l NAA.
The results revealed that the morphogenetic response percentage of the
cultured explants on the different media ranged from 62.5% to 79.2%.
Microshoots initiated after 10 days of culture s howed significant variation
P< 0.001) on number of microshoots per explant at 4 th week of culture.
Maximum number (3.0) of microshoots per explant was obtained directly
from the explants when BAP (1.0 mg/l) was used in combination with NAA
(0.2 mg/l). Root initiation from the explants was noted after 14 days of
inoculation. Hairy roots were also formed on the explants cultured in all
culture media but MS medium supplemented with 0.5 mg/l kinetin and 1.0
mg/l IAA gave higher number of hairy roots. MS medium supplemented
with 1.0 mg/l BAP and 0.2 mg/l NAA exhibited better in vitro shoot
initiation over MS medium containing kinetin and IAA . After 4 weeks of
culture, microshoots were transferred to 2.0 mg/l BAP and 0.2 mg/l NAA
medium for shoot elongation and ro ot formation. Developed plantlets were
then acclimatized after 8 weeks of culture. It could be concluded that BAP
and NAA combination was best for clonal propagation directly from
cotyledonary nodal explants of tomato cultivar KC 1.
