Canola, Rapeseed, and Mustard: For Biofuels and Bioproducts - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 147

Brassica species seed remains viable in the soil for many years, creating a
volunteer problem for pedigreed seed production [ 139 ]. For canola/rapeseed/mus-
tard pedigreed seed production in Canada, the use of land not previously sown to
Brassica species for a minimum of a 3-5-year break between a previous Brassica
crop and the pedigreed seed production year is required [ 140 ]. Isolation distances
vary from 100 m for different varieties of canola/rapeseed for open-pollinated
population cultivar pedigreed seed production to 800 m for different varieties of
canola/rapeseed for hybrid cultivar pedigreed seed production [ 140 ]. Similarly,
isolation distances from distances vary from 200 m for different varieties of
mustard for open-pollinated population cultivar pedigreed seed production to
800 m for different varieties of mustard for hybrid cultivar pedigreed seed produc-
tion [ 140 ]. The canola/rapeseed/mustard pedigreed seed plots must be free of
primary noxious weeds and must have not more than 1 in 10,000 plants of harmful
contaminant species which include B. napus , B. rapa , B. juncea , R. raphanistrum ,
and S. alba. Canadian canola/rapeseed/mustard pedigreed seed production stan-
dards are similar to the canola/rapeseed/mustard pedigreed seed production stan-
dards used by most Organization for Economic Cooperation and Development
(OECD) member countries. This facilitates the movement of pedigreed canola/
rapeseed/mustard seed globally.
Pure inbred line, pure DH line, and open-pollinated population rapeseed/mus-
tard/canola cultivar pedigreed seed lots are sown in plots that meet the above land
requirements and are grown subject to all of the above requirements. The pedigreed
seed production plots are bulk harvested and the pedigreed seed produced assessed
for purity, germination percentage, and seed quality [ 140 ]. Hybrid rapeseed/mus-
tard/canola cultivar pedigreed seed lots are sown in plots that meet the above land
requirements and are grown subject to all of the above requirements. The manage-
ment of hybrid cultivar component pedigreed seed production plots depends on the
type of pollination control systems used.
If a genetic male sterility (GMS) pollination control system [ 99 ] is used to
produce the hybrid seed components, the female line is homozygous recessive
(ms/ms) for male sterility and the maintainer line is heterozygous for male fertil-
ity/male sterility (Ms/ms). 1:1 to 4:1 strips of the female line and maintainer line are
grown with honeybees used to assist in the transfer of pollen from the maintainer to
the female line. The maintainer line is removed from the plot post-flowering and the
seed on the female line bulk harvested. The maintainer line and the pollen parent for
hybrid seed production are male fertile and are grown in isolated fields and bulk
harvested [ 141 ]. The hybrid seed is produced using strips of varying ratios (from
~1:1 to 6:1) of the female line and the pollen parent for hybrid seed production. The
GMS female line segregates 1:1 for male sterility and male fertility and must be
rogued prior to flowering to ensure pure hybrid seed production. Honeybee hives at
~2-4 hives per ha are used to ensure adequate pollen transfer [ 141 ]. The pollen
parent for hybrid seed production is removed post-flowering. The female line is
bulk harvested and the pedigreed hybrid seed produced assessed for purity, germi-
nation percentage, hybridity, and seed quality [ 140 ].