A method of inducing in vitro flowering and fruiting of strawberry plants obtained by shoot apex culture was investigated. When strawberry plants were cultured in the flask (300 ml), the crown did not enlarge over 3 mm diameter, whereas when cultured in a culture-bottle (100mm × 110mm × 100mm), the crown enlarged to 5 mm diameter.
A June-bearing type strawberry, 'Toyonoka', and an ever-bearing type, 'Summerberry' with 3 mm crown diameters did not differentiate flower buds, whereas those with 5 mm crown diameters were induced to flowere.
The percentages of flower buds differentiated by 'Toyonoka' and 'Summerberry' crowns were 22.2 % and 84.2 %, respectively, whereas only 11.1 % and 36.8 %, respectively, flowered.
Thus, culture-bottle system enabled in vitro flowering of strawberry. Using this system, fruits were obtained by artificial pollination.