Protocols for Micropropagation of Woody Trees and Fruits

448
M.G. OSTROLUCKÁ ET AL.
regeneration ability was evaluated after 5 weeks. Data evaluation was performed
using Statgraphic analysis of variance and multiple range analysis. The optimal
composition of shoot regeneration medium and zeatin concentration for the majority
of tested cultivars is presented in Table 1.
The results showed that shoot regeneration ability is highly depending on
cultivar and cytokinin type and concentration. Zeatin at concentration 2 mg l –1 was
the most favourable for shoot regeneration in V. corymbosum cultivars (Figure 1A).
On an average 10.16–15.23 numbers of shoots were regenerated on the medium
supplemented with 2 mg l –1 zeatin with the highest number of shoots in cv. ‘Brigitta’
(Ostrolucká et al., 2002).
Figure 1. Micropropagation of V. corymbosum, cv. ‘Berkeley’ A) Shoot regeneration from
dormant apical and axillary buds on AN medium with zeatin 2 mg l –1 . B) Adventitious shoot
zeatin.
C) Shoot proliferation on medium with 0.5 mg l –1 –1
regeneration on leaf explants after 4 months of cultivation on medium with 0.5 mg l
zeatin.
2.3.2. Shoot Regeneration via Adventitious Organogenesis
in Vaccinium corymbosum L.
Adventitious organogenesis is very efficient to scale up clonal production of selected
genotypes of several Vaccinium species (Gajdošová et al., 2006). Vaccinium
corymbosum L. – cv. ‘Berkeley’ was tested for adventitious shoot induction. As a
primary explants leaves of in vitro plants with cut margins, were placed horizontally
with adaxial surface on the culture medium. AN medium of the same composition
supplemented with 0.5 mg l –1 zeatin (Table 1) was used for adventitious bud
induction from leaf tissue. After 5 weeks of cultivation explants were transferred on
AN medium of the same composition for shoot regeneration and multiplication.
Percentages of explants regenerating shoots and number of regenerated shoots per
explant after 3 subcultures, with subculture interval 5 weeks, were recorded.
Multiple adventitious shoots were formed on leaf explants cultivated on AN
medium with 0.5 mg l –1 zeatin, produced via direct regeneration. Regeneration
ability of the cultivar ‘Berkeley’ was high (18.0 shoots/explant) what is in correlation
with regeneration ability achieved via culture of apical and axillary buds.
After 3 subcultures on the same medium high number (237.14) of vigorous shoots
with good elongation growth was obtained per explant in cv. ‘Berkeley’ (Figure 1B).