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In vitro propagation of strawberries is a promising alternative to traditional propagation, since it provides better sanitary status of plants. The possibility of somaclonal variation presents one of the drawbacks of this method, but this phenomena can be minimised by the choice of optimal tissue culture procedure. To evaluate the influence of in vitro growing on economically important traits of strawberry cv. Marmolada, rooted plants were produced in vitro from a long term and from a newly established culture. These plants were used as mother plants for short multiplication in the field.Vegetative and generative traits of their runner plants were compared with conventionally produced cold storage plants and plants derived directly from tissue culture. Statistically significant differences were observed among different plant types in the number of runners per plant,number of flowers per plant, number of fruits per plant and yield per plant. The most pronounced differences were observed in the number of fruits per plant and in the yield per plant. Plants obtained directly from tissue culture were almost twice as productive as conventionally produced cold storage plants. Conventionally produced cold storage plants had statistically significantly higher yields and fruit number per plant than runner plants derived from micropropagated mother plants. High yields of plants obtained directly from in vitro were mainly the results oftheir significantly prolonged ripening.

Successful shoot regeneration in somatic tissue is the basic requirement for in vitro induction of genetic variability as the new tool in plant breeding. Somatic tissue excised from in vitro multiplied strawberry plants were tested on ability for plant regeneration. Leaves, petiole and stipules were inoculated on initial medium with BA and 2,4-D, or on medium with BA only after 1 hour pulse treatment with 2,4-D. Callus was induced on all sliced surfaces of explants inoculated on initial medium with growth regulators BA and 2,4-D during first 7 days of culture. Explants inoculated on initial medium with BA, after pulse treatment with 2,4-D did not develop callus but abundantly produced fenolic compounds, and tured necrotic in the first 24 hours. Spontaneous plant regeneration was noticed on leaves explants with less developed callus tissue on initial medium with growth regulators duringsecond week of culture. High percentage of explants with regenerated shoots were obtained after transfer on hormone-free medium. The highest plant regeneration ability was in leaf tissue, less in petiole and stipules. Callus induced in leaf tissue showed ability for constant plant regeneration during three months of culture and careful 4-week interval transfer on basal MS medium with 4.4¼M BA and 40 g/l sucrose.