Abstract:
The present study was undertaken to investigate optimization of media in vitro propagation of
sweet orange cultivar from Washington, Valencia and tanjelo orange explants. The explants
were collected from three sweet orange cultivars. The result indicated the highest shoot
response from Washington orange cultivar with maximum shoot proliferation rate (99.75%),
shoot number per explant (3.10), shoot length (10.70cm), leaf number per explants (12.50)
after three weeks of culture. In all experiments no growth was observed for basal MS medium.
The root induction was observed after 15 days of culturing. Significant rooting rate, root
number and root length were observed for all treatments. Among the cultivars, significantly
the highest rooting rate (81.255), root number (4.95), and root length (2.95cm) were recorded
for Washington orange cultivar. The least rooting rate (48.45%), root number (3.55) and
rootlength (2.26cm) were observed from Valencia cultivar. The effect of MS medium
supplemented with NAA on root response rate, root number and root length of microshoot
generated from nodal segment explants of three sweet orange cultivars indicated that
microshoots from Washington orange cultivar has demonstrated significantly the highest
rooting rate (84.90%), root number per microshoot (5.20) and root length (3.05cm) for MS
medium supplemented with 1.5mg/L NAA. The comparison of different concentrations of IAA
and NAA on root induction of microshoots from sweet orange cultivars demonstrated NAA as
the more effective hormone than IAA. Phytohormones combinations of IAA (1.2mg/L) and
kinetin (2.0mg/L) was found to be the best for shoot proliferations
