In order to determine the proper media for the induction of callus and the differentiation of organs, the histological orgin of multiple shoots, and degree of the virus infection of plantlets, the meristem tissues and anthers of strawberry have been cultured on modified Murashige & Skoog´s and Linsmaier & Skoog´s media containing various levels of growth regulators. The results obtained were as follows:
Calluses were induced from the excised side of the merisiem tissue or filament and the surface of meristem tissue, and they could be classified into two types of friable and knobby callus. The best callus growth was observed in the media containing 0.2∼2㎎/ℓNAA or 2, 4-D plus 2㎎/ℓ kinetin or BA respectively.
Meristem tissue was developed into a plantlet on 0.2㎎/ℓ kinetin added medium but multiple shoots from a meristem were formed on the media with 2㎎/ℓ BA or kinetin atone or added 0.2㎎/ℓ NAA. Multiple plantlets were differentiated from somatic callus induced by anther culture.
After 4 weeks in culture the adventitious roots were formed from callus tissue or bases of shoots on media supplemented with 0.2㎎/ℓ 2, 4-D and NAA plus 2∼4㎎/ℓ kinetin, and most large shoots have roots after 8 weeks culture.
The shoot primordia forming multiple shoots were originated from parenchyma tissue beneath the apical meristem, axillary bud, epidermis of leaf blade, vascular bundle of petiole and callus tissue.
After 5 months of culture, multiple shoots were developed into 40∼50 plantlets from an inoculum, subsequently proliferated rapidly. The hardened plantlets Here transfered into the pot with the sterilized vermiculite, and were examined to determine whether the viruses were freed or not by leaflet-grafting to Fragaria virginiana and F. vesca. So far, viruses were not detected in the grafted indicator plants.
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