Brief Summary from
the Encyclopedia of Life
by Jacqueline Courteau
Garden
Strawberry
Fragaria X ananassa
Fragaria x ananassa,
strawberry (or garden or pineapple strawberry), is a perennial
herbaceous plant in the Rosaceae (rose family), a hybrid cultivar of
two wild Fragaria species that is now is cultivated in temperate and
semitropical regions worldwide for its delicious fruit. Although other
Fragaria
species are also cultivated, this hybrid is the primary source
of commercially produced strawberries.
The wild progenitors of F. x ananassa were native to the Americas: F. virginiana, wild
strawberry, grows through eastern North America, while F. chiloensis,
beach strawberry, occurs from coastal Alaska to California and extends
into South America, but the hybrid appears to have originated in
Europe in around 1750, as an accidental cross. The hybrid may be more
complex, as genetic analysis suggests that it contains genes from other
species as well.
Fragaria x ananassa
plants have short, woody stems and a basal rosette of compound leaves,
with 3 coarsely toothed leaflets. The plants are characterized by
stolons-rooting runners that form new plantlets at the tip that
allow them to reproduce vegetatively; commercial propagation is
entirely by the runners. Flowers are white and have 5 parts. The
strawberry, which ripens to red, is not a true berry, but is a fleshy
receptable bearing multiple fruits on the surface—these apparent
seeds are actually achenes, small, one-seeded fruits with hard
coverings that do not split open (dehisce) when ripe.
Strawberries
are often eaten as a fresh fruit, famously in strawberry shortcake, and
are also processed into ice creams, jams and preserves, mousses, fruit
juice, and various baked goods and candies. Strawberries may also be
fermented into wine or liqueur (such as the Italian fragoli).
In 2010, the worldwide commercial production of strawberries was 4.4
million metric tons (mmt), harvested from around 244,000 hectares.
Nearly 10% of the area harvested was in the U.S., but that accounted
for more than than 25% of the total (1.3 mmt). Strawberry production is
particularly important in California, which produces 88% of the U.S.
total, valued at around $2.3 billion annually. The U.S. harvest was
more than 5 times that of any other country. Other major producers
include Turkey, Spain, Egypt, Korea, and Mexico.
Strawberries
are particularly susceptible to damage from frost, and became the
subject of a famous early field test of releasing genetically
engineered organisms into the environment. Research starting in the
1960s had identified a bacterial species, Pseudomonas syringae,
that provides nucleation sites for ice crystals to form (the so-called
“ice-plus” bacteria). With a single genetic modification,
the surface proteins in these bacteria can be altered so that they no
longer provide a suitable ice-formation surface. Bacteria altered to
have the “ice-minus” gene, developed by the California
company, Advanced Genetic Sciences, were tested in a controversial
field experiment on strawberries in 1987, in which a bacterial solution
was sprayed on the strawberry plants before a frost. Although initial
results suggested the modified bacteria did prevent ice formation,
concerns about whether releasing these bacteria for commercial
application might adversely affect snow and ice formation, with
potentially large implications for regional weather patterns, have
inhibited widespread use of ice-minus bacteria in strawberry
cultivation.
(Bailey et al. 1976, California Strawberry
Commission 2012, Domoto et al. 2008, FAOSTAT 2012, Flora of China 2012,
Nottingham 2003, van Wyk 2005.)
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© Jacqueline Courteau
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