Agriculture Reference
In-Depth Information
collected for food.
Allium fistulosum
was probably selected from
A. altaicum
in
northern China near the southernmost border of its natural area. Interspecific
hybrids between
A. altaicum
and
A. fistulosum
have high pollen and seed fertility.
Japanese bunching onions have been grouped into four major types: the
'Kaga', 'Senju', 'Kujyo' and 'Yagura negi' groups (Inden and Asahira, 1990). The
first three of these groupings correspond to cultivars adapted to the coolest,
intermediate and warmest regions of Japan, respectively. The differences between
groups that make them suitable for cultivation in contrasting climatic zones lie in
their degree of winter dormancy and their growth rate under low temperature.
Kaga types, being adapted to cold regions, become dormant in the winter and grow
very slowly at mean air temperatures of around 5°C, whereas the Senju and Kujyo
groups grow actively in cool conditions, the growth rate being faster for the latter
than the former, and they do not become winter dormant. The Kaga group is grown
to produce thick, blanched pseudostems since they form large leaves and do not
branch readily. Long pseudostems and blanching are promoted by repeatedly
earthing-up as the plants grow. The Senju group is similarly cultivated to produce
long, blanched pseudostems. They are grown in central Japan, near Tokyo. The
Kujyo group branch easily and are mostly grown for tender, green leaves, although
some cultivars are used for blanched pseudostem production in southern Japan.
Yagura negi is a home garden crop that produces numerous bulblets and shoots
atop its flower stalk. It is winter dormant and is grown to produce edible green
shoots in spring and summer. It tillers readily and is propagated by offshoots.
Garlic,
Allium sativum
L.
Garlic (see Plate 1) is thought to have evolved from wild ancestors in a broad area
of central Asia stretching from the Tien Shan mountains in the east to the
Caucasus in the west. Some authorities consider that
A. longicuspis
is a separate
species from which garlic evolved, but others consider that
A. longicuspis
is a wild
or feral form of garlic (Fritsch and Friesen, 2002).
Allium tuncelianum
has also been
suggested as an ancestor of both garlic and
A. longicuspis
. It smells like garlic and
has similar floral morphology, but it is a non-bulbing species. The natural habitat
of ancestral garlic was probably gullies and rocky valleys where some water was
available, in arid or semi-arid areas. Garlic bulbs in summer and can therefore
survive periods of extreme dryness as a dormant bulb. It is also very cold-hardy.
Fritsch and Friesen (2002) divided garlic into several informal cultivar groups:
●
the
Longicuspis
group of Central Asia, which bolt and some of which are
still seed fertile and which also produce many small top-sets.
●
the
Sativum
group from the Mediterranean, which includes bolting and
non-bolting types.
●
the
Ophioscorodon
group from central and eastern Europe, which bolt and
produce long, coiling scapes with few large top-sets.
