Protocols for Micropropagation of Woody Trees and Fruits

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A. GAJDOŠOVÁ ET AL.
2. in vitro rooting on AN medium supplemented with 0.8 mg l –1 IBA and 0.8
g l –1 activated charcoal.
With both approaches the percentage of rooting reached 80–90–95% in depen-
dence on cultivar. The rooted plantlets transplanted into peat substrate were sub-
sequently acclimatized. Hardening of plantlets was performed under greenhouse
conditions without any special light treatment, with regular irrigation, in containers
at the beginning (2 weeks) covered by lid, later opened. Plantlets in length 100–150
mm (after 2 months) were replanted into bigger containers (120 mm in diameter)
and transferred to Research Station Krivá, where they were placed under open-air
conditions. Transfer of regenerants from in vitro to ex vitro conditions and their
acclimatization was successful, as almost 80–90% of transferred plants survived
(Figure 1E, 2A,B).
2.5. Field Testing
Transferred plants in length 100–150 mm were kept in containers (120 mm in
diameter) placed under open-air conditions for 2 years. Two years-old plants were
planted into acid peat-made bed, with the volume of 10 l peat per plant, and pH 3.8
in experimental orchard of Research Station Krivá. In vitro plants were from the
beginning characterized by more synchronous growth. No morphological variations
or anomalies were observed among them. In general, during the first 2 years after
transfer to soil, in vitro-derived plants formed more shoots and had a bushier growth
habit with a higher number of flower buds. The beginning of breeding was slightly
delayed for in vitro-derived plants. This is an advantage for commercial growers,
because during the first 2 years after planting fruit setting is not desirable. On the
contrary, the vegetative growth should be supported in order to strengthen full
fertility during following years. Later no obvious morphological differences were
visible between in vitro and by cuttings propagated plants. Regarding fertility and
berry quality the plants are also equivalent.
Figure 2. Hardening and acclimatization of in vitro-derived V. vitis-idaea plants in containers
under A) greenhouse conditions and B) under open-air conditions.