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Oct 23, 2013 (3 years and 11 months ago)

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Brassica Species

Rapeseed

Oil Crops









Edwin Mendez

Plant Breeding


Brassica species


Oil Crops


Rapeseed is obtained from the species of Brassica, member to the Cruciferae
(Brassicaceae), and within the genus of some 160 species,

mainly annual and biannual
herbs (Weiss, 1983)
.

In Latin, the name rape translated into rapum meaning turnip
.

There are two types of rapeseed the Argentine rape, Brassica napus, also know as the
winter rape and the Polish rape, Brassica campestris (rap
a) also know as the summer
rape
.

Brassica napus and Brassica campestris are the most important as commercial
oilseed producers in the Cruciferae family
.



Although the origin of rape is not specifically identified in text, most scientists
believe that rape

originated in the Eurasian area, which includes India, China, and Japan
.

The earliest recorded history of this crop dates back to 2000 B
.
C
.

A proposed secondary
center of origin is Turko
-
Iranian region
.

In the Middle ages the most important use of
rapes
eed was oil for lamps in northern Europe (Weiss, 1983)
.

During this time the oil
from rapeseed was mainly used for lighting
.

It was only the poor that used rape oil as an
edible oil
.

The oil was also used in soap making
.

In the nineteenth century with the
introduction of other sources of oils such as petroleum, the cultivation or rape decreased
in western Europe, but increased in eastern Europe
.

There was no significant increase or
decrease in production of rapeseed in Europe up until the 1940s
.

Since then
it has become
one of Europe’s most important oilseed crop
.



The initial used of rapeseed was mainly for industrial uses such as lighting, soaps,
and lubrication
.


Rapeseed for edible purposes was not fully exploited by western nations until the
end of Wor
ld War II
.

Rapeseed varieties containing low erucic acid oils enhance its use
as and edible oil
.

The mark of the western
-
based industry was made when Canada
extracted edible oil in 1956 (Downey, Klassen, and McAnsh, 1974)
.

Leftovers from oil
production wer
e used as livestock feed
.

The edible oil from rapeseed is known as Canola
oil
.

Today over 13
.
2% of the world’s edible oil comes from the oilseed Brassicas
(Robbelem, 1989)
.



Production



The areas of production of rapeseed have changed thought history
.

For many
years the number one producer of rapeseed was Canada but that is not true today
.

In
recent years China has become the world’s largest producer of rapeseed producing 12
.
6
million metric tons in 2006 (FAOSTAT 2006)
.

Second in world production of r
apeseed
is Canada with Indian, Germany and France rounding off the world’s top five producers
.

World production of rapeseed is currently around 45
.
9 million metric tons (FAOSTAT
2006)
.


Principal breeding objectives



Unlike other oil crops the main breedi
ng objective of rapeseed has always been
with breeding to increase seed quality
.

Breeding for seed quality usually means breeding
for better quality oil and breeding for low or high acid concentrations
.

The average oil
content in rapeseed ranges from 36 to

50 %. Improvement of oil content is an important
goal due to the primary economic value of the oil component and its relatively high
heritability
.

However, breeding for high yield is not ignored
.

Improvement of
productivity also includes several paramete
rs such as early maturing resistance to frost or
cold, resistance to diseases, resistance to pest, and resistance to lodging
.


Parental Material



Rapeseed is in the family Cruciferae (Brassicaceae), Genus Brassica
.

Both
Brassica napus and Brassica campes
tris(rapa) are consider rapeseeds
.

Common names of
B
.

napus and B
.

campestris include rape and rapeseed
.

The relationship between species
in the Cruciferae family can be explain by well
-
know triangle of U(Murphy, 1994)
.

The
triangle includes 6 species
.

Thr
ee amphidiploid species, B
.

napus (AACC, 2n=4x=34), B
.

juncea (AABB, 2n=4x=36) and B
.

carinata (BBCC, 2n=4x=34)
.

The amphidiploid
species likely originated in nature form diploid ancestors through unidirectional
hybridization followed by spontaneous chromo
some doubling (Murphy, 1994)
.

Three
diploid species are orientated at the corners of the triangle, B
.

nigra (BB, 2n=16), B
.

rapa
(AA, 2n=20), and B
.

oleracea (CC, 2n=18)
.

The triangle represents the interspecific
hybridization between species of the Brassi
ca family
.

Combination of B
.

rapa (AA,
n=10) and B
.

Oleracea (CC, n=9) forms, gives rise to B
.

napus
.


Genetic variation of B
.

napus and B
.

carinata, which do not occur in the wild, the
polyphyletic origin of B. juncea has given rise to large morphotypic v
ariation and goes
back to ancient times at least in the Middle East and India (Murphy, 1994)
.

It is most
likely that most genetic variation of B
.

napus is in the Mediterranean region, the area of
overlap between the more widely distributed B
.

rapa and B
.

o
learacea (Murphy, 1994)
.

Germplasm collection of Brassica species is also available research stations in India
.

Genetic collection of rapeseed can also be found in other areas such as China, India and
Japan
.

Indigenous collections and cultivated varieties

can also be a source of genetic
variability
.


Plant Culture


Rapeseed does well in a wide range of soil types, but for optimal performance it
prefers loamy soils
.

Rapeseed nutrients requirements are vary similar to those cereals
.

The main differences are
that rapeseed required higher amounts of nitrogen
.

Studies have
been done to examine the plant density of this crop
.

A spacing of 15 cm between rows is
optimal
.

Spacing between each plant should be between 10 and 20 cm
.

There was no
significant difference

between plant spacing
.

Rapeseed should be given full sunlight with
below 25° C of day temperature
.

Depending on variety and time of sowing, rapeseed can
be grown as
annuals or biennials
.

Rapeseed grown in greenhouses can be lit with mercury light to provi
de a 16 hour
day
-
length
.

Green house day temperature should be kept 21 ± 5°C
.

Most production of
rapeseed is done in the field
.



Pollination and Morphology


Rapeseed produces yellow nectar
-
bearing flowers, which are able of both self
-
fertilization and int
raspecific cross
-
fertilization
.

Honeybees are the primary pollinators of
rapeseed
.

The flowers contain 4 petals
.

The pods are located 18 inches above the crown
to the top of the pant, they average from 1 to 1 1/2 inches long, and they contain the
seeds
.

Th
e leaves are mainly originated towards the base of the plant
.

The leaves can be
described as large green board leaves
.

The plant as a whole can grow 2 to 4 feet tall with
branching form the central stem
.



Breeding


Programs in breeding for Brassica oil
crops have always been connected with dire
improvements of seed quality
.

Public breeding programs do the majority of Brassica oil
seed breeding
.

According to the long
-
term and short
-
term goals of the breeding program,
there are many different procedures b
reeders can use to develop a desire trait such as;
haploid techniques such as microspore culture for the production of doubled
-
haploid
lines, wide hybridizations using embryo rescue techniques, or protoplast fusion (Fried
and Lühs, 1999)
.

Once a desirable
trait has been identified crossing, breeding selection,
and testing may take place
.

The majority of rapeseed cultivars are pure line derived from
pedigree selection breeding or modified pedigree selection
.

The majority of Brassica oil
seed breeding is don
e by public breeding programs
.


The initial step in forming a breeding program is to generate a wide arrange of
germplasm that will contribute to desired new species
.

For rapeseed species a germplasm
can be formed by collecting rapeseeds from genebanks, br
oaden the genetic basis in the
production or resynthesized rapeseed by crossing the original ancestors (Fried and Lühs,
1999), collecting cultivated species or searching the proposed origin
.



After gathering wide germplasm, hybridization may occur
.

The o
ptimum
planting date for rapeseed should occur in mid
-
August
.

To produce a F1 hybrid, parent
(1) and parent (2) containing solely a desired genotype are planted within pollination
proximity
.

In this case the A
-
genome plant and a C
-
genome plant should be be
tween 10
-
20 cm between plants and 15 cm between rows
.

The parents must cross in order to
produce a desired progeny
.


Brassica species can be self
-
pollinated or cross
-
pollinated, but in order to get
desired traits in the progeny self
-
pollination must be pre
vented (Fried and Lühs, 1999)
.

Several cytoplasmic male sterility lines have been developed in Brassica species through
alloplasmic types
.


Harvest for the first generation can begin when the pods on the plant become
yellow and the seeds become dark, the s
eeds will become lose withing the pod
.


Pollen must be transferred between parent (1) and parent (2)
.

Pollen distribution
can be accomplished by insects such as bumblebees, or artificially pollinating
.

If pollen is
to be collected it should be used immedia
tely
.

In artificial pollination, pollen of rapeseeds
should not be stored for prolonged periods of times
.

Seeds are then gathered from both
parents
.

The F1 progeny should exceed desired characteristics of both parents if self
-
pollination was avoided
.


Pla
nting can be done mostly any time of the year 6 weeks before a frost but
optimal is mid
-
August
.

The F1 generation may occur at this point, space between each
plant should be sufficient enough to examine if you are using a pedigree selection
.

Plants
that ha
ve been observed to be self
-
pollinated should be disregarded
.

Selection for
improved plant should occur at this stage
.

Backcrossing can also be done at this point in
the breeding program if a dominate allele is present in desired plant
.

In the F2 generatio
n
plant a sufficient amount of crops in order to allow plants to be individually examine and
select superior plants
.

The following generations should consist of field testing,
comparison between generations, testing in different locations, and identifying
traits in
progenies
.


Thought biotechnology, molecular markers are a way to identify if the desired
gene was inherited onto the new hybrid
.

Using DNA based marker such as RFLP,
RAPDs, SSR, PCR, AFLP, or SNPs one can identify and monitor at the genetic leve
l if
the trait desired was inherited
.

Some of the more common molecular markers used for
Brassica oils are RFLP and RAPDs
.

Biotechnology also allows specific methods of
introducing new genes into a crop gene
.

In Brassica oil crops specific biotechnology
te
chniques used to introduce new genes into a crop include; recombinant DNA, chemical
mutagenesis, and screening
.


After years of testing, analyzing, and breeding the new
hybrid can finally be
released
.



Special Study


Double Haploids



One of

the most common breeding techniques in Brassica species is the use of
double haploid techniques
.



Double haploids enable breeders to develop completely homozygous genotypes
from heterozygous parent in single generation
.

In a rapeseed, double haploids are

produced from F1 hybrids by means of chromosomal doubling
.

By the R3 generation
yield test and field selections are made by identifying desirable combination of
characters
.

This method allows release of new Brassica oilseed cultivars within two years
as o
pposed to conventional breeding methods
.


In studies done by the Division and Plant Breeding Program in the Czech
Republic, two types of creating double haploids were examine
.

Creating double haploids
by spontaneous haploids were analyze in terms of the
advantages of double haploids and
practical uses of double haploids
.

Creating double haploids by
In vitro

androgenesis was
also examined in their breeding program
.


Double haploids using spontaneous haploids are done acquiring natural occurring
haploids f
ound in some rapeseed cultivars and treating it with colchicine
.

The treatment
of colchicines develops haploid line into a completely double haploid line
.

This method
of double haploids reached approx
.

11% higher oil yield than parent cultivar (Kucera,
Vya
dilova, and Klima, 2002)
.


Douple haploids using
In vitro

androgenesis are produce from anther culture
.

This
technique is used by inducing cell division and embryo formation in pollen cells
.

After
plantlet formation the rapeseed plant is take and colchicin
e treated
.



Advantages of using double haploid in oilseed rape breeding consist primarily in
substantially reduced time to produce and release cultivars (Kucera, Vyadilova, and
Klima, 2002)
.

Using double haploids techniques in rapeseed breeding can reduc
e the
amount of time to produce a cultivar by nearly half as opposed to conventional breeding
.



















Resources


Australia
.

Department of Health and Ageing Office of the Gene Technology Regulator
.

The Biology of Brassica Napus L
.

(canola)
.

Austr
alian Government, 2008

http://www
.
ogtr
.
gov
.
au/pdf/ir/biologycanola08_2
.
pdf


Downey, R. K., A. J. Klassen, and J. McAnash.
Rapeseed
. Canada ‘s “Cinderella” Crop.
Canada; Rapeseed Associatio
n of Canada, 1974.


Fried, Wolfgang and Lühs, Wilfried W
.

Breeding of Rapeseed (Brassica Napus) for
Modified Seed Quality


Synergy of Conventional and Modern Approaches
.

Giessen:
Ludwigst, 1999


Food and Agriculture Organization of the United Nations
.

20
08
.

17 April 2008

http://faostat
.
fao
.
org/
.


Gill, Khem, S
.

Breeding Oilseed Crops
.

Ludhiana: BICO, 1980
.


Kucera, Vratislav, Miroslava Vyvadilova, and Miroslav Klima
.

Utilisation of Doubled
Haploids in Winter Oilseed

Rape (Brassica napus L
.
) Breeding
.

Czech J
.

Genet
.

Plant
Breed

38 (2002): 50
-
54
.


Lyakh, V
.

A, A
.

Soroka, and M
.

G
.

Kalinova
.


Pollen storage at low temperature as a
procedure for the improvement of cold tolerance in spring rape,

Brassica napus

L
.

Plant
Breeding

117 (1998): 389
-
391
.



Murphy, Dennis, J
.

Desiner Oil Crops


Breeding, Processing and Biotechnology
.

New
York: Verlagsgesellschaft, 1994
.



Robbelen, G
.
, R
.

K Downey, and A
.

Ashri,
Oil Crops of the World
.

New York:
McGrawhill, 1989
.


Scehranz M
.

E
.
, and T
.

C
.

Osborn
.

Novel Flowering Time Variation in Resynthesized
Polyploid Brassica Napus
.


http://jhered
.
oxfordjournals
.
org/cgi/reprint/91/3/242
.
pdf


Sleper, David A
.
, and John

Milton Poehlman
.

Breeding Field Crops
.

Missouri: Blackwell
Publishing, 2006
.


Weiss, E
.

A
.
,
Oilseed Crops
.

London: Longman, 1983
.