Canola, Rapeseed, and Mustard: For Biofuels and Bioproducts - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 136

[ 23 , 33 - 35 ]. There is tremendous variability in Brassica genomes, and some plant
scientists have speculated that this made Brassica unusually responsive to selection,
a reason for their widespread adoption and success as oilseed and vegetable
crops [ 25 ].
Plants of the Brassicaceae family were among the first to be domesticated by
man, with initial domestication occurring several thousand years ago. The three
diploid Brassica species B. nigra , B. rapa , and B. oleracea were the first to be
domesticated, and these species have been cultivated for a very long time. The
amphidiploid species were domesticated later but probably still very early in
mankind's agrarian evolution [ 36 ]. Rapeseed (likely B. rapa ) was cultivated in
India in 4000 BC [ 37 , 38 ]; in China, Japan, Greece, and Italy 2,000-2,500 years ago
[ 16 , 23 , 39 ]; in Europe 800 years ago [ 23 ]; and in North America 60 years ago [ 37 ].
Centers of origin provide useful information regarding probable areas of initial
domestication. Brassica rapa is thought to have a primary center of origin in the
Indian subcontinent with secondary centers of origin in Europe, the Mediterranean
area, and in Asia [ 36 ]. Brassica oleracea and B. napus are presumed to have
originated in the Mediterranean area [ 36 ]. Brassica nigra and B. juncea species
are thought to have originated in the Middle East [ 40 ], while B. carinata is
presumed to have originated in northeast Africa [ 41 ]. All of the Brassica species
of the U triangle have spring habit forms. Brassica oleracea is primarily a biennial,
but B. oleracea var. alboglabra is a spring habit variant in this species. In addition,
B. napus and B. rapa species have winter-annual habit types [ 42 ]. The winter habit
types of B. napus and B. rapa species are more productive than the spring forms;
however, they are less winter hardy than winter cereals [ 41 ].
Brassica rapa appears to be the most widely distributed oilseed Brassica
species. At least 2,000 years ago, it was distributed from the Atlantic islands in
the west to the eastern shore of China and Korea and from northern Norway to the
Sahara and northern India [ 36 ].
Canola/Rapeseed/Mustard Production
Different Brassica oilseed species are adapted to, and grown in, different regions of
the world. Brassica juncea and B. rapa are the predominate species in the warmer
semitropical regions of the world, while in cooler temperate regions, B. napus and
B. rapa predominate. Brassica carinata is limited to Ethiopia and northeast Africa
[ 43 ], while B. nigra is grown in Europe and Asia [ 44 ]. Brassica oleracea is
exclusively a vegetable crop produced globally [ 20 ]. Brassica juncea is an impor-
tant oilseed species in India [ 45 , 46 ], Pakistan, and China [ 43 ] and is an important
condiment crop in Canada [ 43 ], which has recently been converted to a new
Canadian double low edible oilseed crop called canola juncea [ 11 ]. Brassica
napus is the most important oilseed species in Australia, Europe, Canada, and
China, while B. rapa is the predominate species in India and northwest China
[ 16 , 38 ]. Winter habit B. napus types are grown in southern Europe and China,