Protocols for Micropropagation of Woody Trees and Fruits

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V.M. KULKARNI ET AL.
Figure 2. In vitro regeneration of banana via shoot-tip multiplication pathway. A) Sword
suckers of a field growing banana plant. B) Shoot-tip from sword sucker cultured on a filter
paper bridge, bar = 10 mm. C) Swelling of the shoot-tip after 10 days of initiation, bar = 10
mm. D) Shoot-tip multiples in vitro. E) Profusely rooted shoots (complete plantlets). F)
Greenhouse hardened plantlets. G) Field planting of the tissue culture derived plants.
The shoot apices are transferred to a 250 ml capacity conical flask and washed with a
standard liquid detergent followed by several washes with distilled water. For surface
sterilization, the explants are sequentially treated with commercial chlorine bleach (5%
w/v, 15 min), 70% ethanol (8 min) and 0.1% HgCl2 (7 min), under aseptic conditions.
Each of these treatments is followed by minimum of 4 rinses with sterile distilled water,
and excision of few sheathing leaves and some corm tissue. Finally, the shoot apices
(trimmed to a size of 1.0–1.5 cm, with minimum basal corm tissue) are cultured on a
filter paper support (Figure 2B) on SM1 liquid medium.
2.1.2. Proliferation of Multiple Shoots and Rooting of Individual Shoots
After 10 days of initiation, the cultured shoot tips are sectioned vertically and subcultured
on SM2 medium (Figure 2C). Multiple shoots (Figure 2D) formed need to
be maintained as stock cultures by regular subculturing at an interval of about 4
weeks, on SM2 medium. The stock cultures are freshly initiated as and when
necessary. Individual shoots can be separated from the shoot-tip multiples and
rooted by culturing on SM3 or SM4 medium.