Protocols for Micropropagation of Woody Trees and Fruits

BAMBOO MICROPROGATION BY AXILLARY SHOOTS 469
Table 2. Minimum autoclaving time for plant tissue culture media (adapted from
Burger 1988)
Volume of medium per vessel (ml) Minimum autoclaving time (min)
25 20
50 25
100 28
250 31
500 36
2.3. Bud Break and Development of Lateral Shoots
Insert nodal segments vertically into the gelled culture medium in the upright
position up to the nodal region (Figure 2A). N 6 -benzylaminopurine (BAP), at a
concentration of 3 mg l –1 , has given the best results in our work with Guadua
angustifolia. Table 3 could be referred to look for adequate composition of PGRs for
other species.
Figure 2. Growth of the bamboo nodal segments. A) Nodal segment inserted upright in the
culture medium, B) Nodal explants with a growing bud.
Initially, place cultures in the dark at 26°C for 2 weeks to reduce oxidation and
necrosis. Thereafter, transfer them to light, 16-h photoperiod regime, where axillary
buds start growing (Figure 2B). The light intensity does not seem to be a critical
point for growth of bamboo axillary buds, since there are references in the literature
with successful bud development under light intensities ranging from 10 to 140
µmol m –2 s –1 , provided by fluorescent tubes.
Subculture every 3–4 weeks to fresh culture medium with the same composition
until a well-developed axis forms (Figure 3A). Depending on the size of the explants,
larger vessels might be necessary. Keep in mind autoclaving time for larger medium
volumes (Table 2).