Gene map of Tomato (Solanum
lycopersicum) (2n = 24)
Garden tomatoes have a long history of cultivation, and the
genetics of various ornamental varieties is well understood.
Small differences among varieties can have enormous commercial
consequences. For example, wild varieties tend to have small,
dense fruits. Crossing of one such wild strain to the common
commercial strain resulted in a plant with in an increase in
solid matter of several percent. Where each 1% of solid
material in plants used for catsup or tomato paste is worth
several million dollars annually, there is strong economic
incentive to understand tomato genetics. The complete genome
sequence of the cultivar Heinz
1706 was published in 2012.
The first genetically modified organism
used as human food was the Flavr Savr
tomato, first marketed by Calgene in 1994. Calgene inserted a
genetically engineered anstisense gene that interfered
with transcription of the mRNA for an enzyme
responsible for early ripening and softening of tomato fruit.
This was intended to ease handling and increase shelf life,
however the Flavr Savr strain was not considered to have as
good a taste as typical tomatoes, and still softened earlier
than desired. In combination with the added cost of
production, Flavr Savr was off the market by 1997.
Figure ©2002 by Griffiths et al.; all text material ©2014 by
Steven M. Carr