In vitro food production for isolated closed environments: formation of ripe tomato fruits from excised flower buds.

Excised preanthesis flower buds of young Pixie Hybrid tomato plants develop into red ripe fruits in aseptic culture on a modified Murashige-Skoog medium with 3% sucrose at pH 5.8. The addition of certain synthetic auxins (IAA, NAA, IBA), auxin precursors (ISA), or cytokinins (KIN, IPA, ZEA, BAP) to the medium improved the percentage of buds developing into fruits, the weight of the ripe fruits, or both. The best results were obtained by an auxin-cytokinin combination of 10 microM IBA with 1 microM BAP. Storage of the excised buds at low temperature (6 degrees C) for up to 4 weeks before transfer to 27 degrees C caused only minimal deterioration in size and number of the fruit crop. Extension of low-temperature storage to 8 weeks produced smaller fruits that took longer to develop. This system could produce fresh, ripe small tomatoes on a sustained basis for up to 2 months for an isolated environment such as a space vehicle or submarine.