Lecture 6. Fruits and
vegetables
Summary
For botanists, the term
‘fruit’ refers to the
seed-containing part of the plant which
develops from the flower ovary after
fertilization. For consumers, fruits are
succulent plant parts (with or without
seeds) that have a pleasant taste and
aroma. Herbs, vines, shrubs and trees
belonging to diverse botanical families
produce fruits. However, two families
dominate in importance in temperate zones
and world commerce, Rosaceae and
Rutaceae.
The term ‘vegetable’ is more
difficult to define, because vegetables
include modified stems, roots, leaves and
fruits in the botanical sense. Vegetables
come from a large diversity of botanical
families, but many of the most familiar
vegetables come from the Solanaceae
(potato, eggplant, tomato, peppers and
others), Brassicaceae (cabbage, kale,
turnip and others) and the Apiaceae
(celery, carrot, parsnips and others).
Fruits and vegetables have been harvested
in the wild for many millennia, but were
brought into cultivation after cereals
and legumes. They are important in diet
particularly because of their content of
vitamins (for example, vitamins A and C),
minerals (calcium, iron and potassium)
and fibre. They are generally low in fat
and protein.
Examples:
- The Rutaceae is a medium-sized
family of more than 160 genera
and 1650 species. They are found
in tropical and warm temperate
regions around the world,
especially in the Southern
Hemisphere, South Africa and
Australia. The family is known
for its fruits, which come
primarily from the Citrus
genus, and its essential oils,
which are used in perfumes and
medicine. The family includes
primarily shrubs and trees,
though there are some herbs as
well. Plant parts, including
fruits and leaves, have a strong
aroma; the essential oils are
found in oil glands, often
appearing as black or translucent
dots on leaves. The genus Citrus
contains a number of species
yielding tropical and subtropical
fruits, including lemons, oranges
and grapefruits. Most commercial
production is in subtropical
regions with a Mediterranean
climate. The group is thought to
have evolved in China, South East
Asia and possibly India. The
earliest records of cultivation
are from China about 2200 B.C.
Arabic people brought many
species into cultivation in North
Africa and southern Europe from
the eight century onwards.
However, many leading cultivars
were not imported into the
Western Hemisphere until the
nineteenth or twentieth
centuries.
- The Rosaceae, a medium-sized
family of more than 100 genera
and 3100 species that, although
cosmopolitan in distribution, are
especially found in temperate and
warm northern regions. The family
includes many trees, shrubs and
herbs. The primary economic uses
are as temperate region
ornamentals and fruits. There are
diverse genera that provide
edible fruit. The cultivated
apple (Malus x domestica)
is one of the most widely
cultivated fruits in temperate
zones. Pears, from the genus Pyrus,
are also widely cultivated,
especially in Europe, the United
States of America, China and
Japan. Both apples and pears are
thought to have originated in the
region stretching from Asia Minor
to the Caucasus, central Asia and
western China. They have been
cultivated for over 4000 years.
Other fruits include quinces (Cydonia),
loquats (Eriobotrya),
strawberries (Fragaria),
cherries, peaches and plums (Prunus),
currants (Ribes) and
raspberries (Rubus).
- The Solanaceae, a medium-sized
family with 147 genera and 2930
species, is dominated by the
genus Solanum with 1400
species. Although cosmopolitan,
the Solanaceae is particularly
diverse in Australia, and Central
and South America. It yields a
wide range of economic products,
including as vegetables,
ornamentals, medicines and, of
course, tobacco. Some notable
species are:
- Tomatoes (Lycopersicon
esculentum), which were
domesticated in Mexico, though
most wild relatives are known
from South America. Spaniards
brought tomatoes to Europe in the
early sixteenth century, from
where they spread throughout the
Old World. They are now one of
the most important salad and
vegetable plants, and their
diverse fruits are prepared in a
great variety of ways.
- Aubergine (Solanum melongena),
which is a native of tropical
Asia. Brought under cultivation
in India, it was carried into
Spain by Arabs in the 8th
century.
- Other vegetables come from the
genus Capsicum (sweet and
hot peppers), domesticated some
3000 – 5000 years ago.
- Nicotiana tabacum (a
tropical American cultigen
domesticated in prehispanic
times), which is responsible for
more deaths than any other plant.
Since the mid-1890s, China has
become the biggest producer and
consumer of tobacco, with an
estimated 300 million
predominately male smokers. One
in eight male deaths in China are
related to tobacco use; if
current trends continue, this
will increase to one in three
male deaths by the year 2050. Nicotiana
rustica (called wild or Aztec
tobacco) – cultivated in
prehispanic times in Mexico and
Eastern North America – was
the original tobacco introduced
to Europe. A small hardy plant,
it is now principally used as a
source of insecticides.
- Other families giving fruits and
vegetables, particularly in
temperate zones, include:
Ericaceae (Arbutus, Vaccinium),
Cucurbitaceae (Citrullus, Cucumis,
Cucurbita, Sechium),
Vitaceae (Vitis).
References:
Anderson, G.J., R.K. Jansen and Y.
Kim. 1996. The origin and relationships
of the pepino, Solanum muricatum
(Solanceae): DNA restriction fragment
evidence. Economic Botany
50:39-380.
Gmitter, Jr. F.G. and X. Hu. 1990. The
possible role of Yunnan, China in the
origin of the contemporary Citrus
species (Rutaceae). Economic Botany
44:267-277.
Prohens, J., J.J. Ruiz and F. Nuez.
The pepino (Solanum muricatum,
Solanaceae): a "new" crop with
a history. Economic Botany
50:355-368.
Williams, D.E. 1993. Lycianthes
moziniana (Solanaceae): an
underutilized Mexican food plant with
"new" crop potential. Economic
Botany 47:387-400.
Questions for
discussion:
What are the plant families that
provide the most common fruits and
vegetables in tropical areas, such as
Southeast Asia?
Can you give some examples from
Thailand of fruits and vegetables that
are in a stage of incipient domestication
or that are relict cultigens?
Perspective for
discussion:
"When first discovering that Lycianthes
moziniana was being utilized by
traditional farmers in Tlaxcala, I formed
a working hypothesis based on the
assumption that this plant was in some
incipient stage of domestication as a
consequence of the preferential treatment
it was being afforded by the farmers.
Subsequent fieldwork revealed that the
species occurred almost exclusively in
traditional agrohabitats, usually under
deliberate, albeit casual, cultivation.
Furthermore, a combination of
morphological and physiological traits of
this species, such as an erect herbaceous
habit; apparently functional autogamy;
large, non-toxic sweet tasting persistent
fruits; and uniform seed germination, are
recognized as characters typically
associated with modifications brought
about during the domestication process
…
During the course of the research, the
working hypothesis was revised to include
the likelihood that this species, instead
of being an incipient domesticate is, in
fact, a relict cultigen. The discovery of
ethnohistorical evidence of knowledge and
use of L. moziniana in the
sixteenth century, although its
domestication status at that time is
unknown, delinits nearly half a millenium
of agricultural change during which an
abandoned, minor cultigen would have had
sufficient time to revert to a more weedy
form.
Taking into account the
anthropocentric characteristics of the
utilized organ (size, flavor, texture,
persistence), the evident antiquity of
the species’ interaction with man,
and its present restriction to
traditional agrohabitats, the hypothesis
is advanced that the agrestic form of L.
moziniana represents the vestigial
remnant of an ancient crop."
From Williams, D.E. 1993. Lycianthes
moziniana (Solanaceae): an
underutilized Mexican food plant with
"new" crop potential. Page 397.
BACK
|
