Rape seed is an allotetraploid crop produced through interspecific hybridization of Brassica oleracea and Brassica campestris. It is bred to have winter or spring types depending on the growing region. The seed is grown for its oil and protein but must have low levels of compounds like erucic acid and glucosinolates that can damage health. Breeding techniques include hybridization, inbreeding, hybrid cultivars using male sterility systems, and transgenic methods to develop herbicide resistance or altered fatty acid compositions for different industrial uses. Quality of the meal is also improved by reducing anti-nutritional compounds through breeding.

1. Breeding Rape seed

2. Rape seed genetics
• Allotetraploid
– Brassica oleracea(9 chr) x Brassica campestris(10 chr)
– Interspecific hybridisation (embryo rescue) and
protoplast fusion
– Resynthesis to provide new genes (resistance etc)
• Winter types (Europe)
• Spring types (Canada and North Scandinavia)
• Brassica campestris grown in short season areas
– short summers or dry summers
• Grown for seed oil and protein
• Transgenic herbicide resistant types

3. Line and population cultivars
• Hybridisation to recombine genes
• Inbreeding (isolation needed)
– pedigree, bulk, SSD
– DH from anther or microspore culture

4. Hybrid cultivars
• CMS-restoration systems
– Ogura cytoplasm (modified via protoplast fusion)
– Restorer naturally linked to high glucosinolate content
– Mix-hybrids
• Self-incompatibility
– incompatible female (maintain with bud pollination)
– multiply female with compatible maintainer
– hybridise with compatible male-line.

5. Transgenic hybrid cultivars
• PGS system (Plant Genetic Systems)
female
Anther specific promoter + RNAse gene (killer gene)
+ Basta resistance gene
Normal maintainer
Fertile plants in female line removed each generation
with Basta spraying.
male
RNAse inhibitor gene

6. Desired oil composition
in rape seed (consumption)
• Low erucic acid (22:1 n-9)
– myocardial damage (two major recessive genes)
• Low unsaturated
– myocardial damage
• High monounsaturated: Oleic acid (18:1 n-8)
• Low polyunsaturated:
– form oxidation products (bad taste and smell)
– especially Linolenic (18:3 n-3) forms trans-fatty
acids upon hydrogenation

7. Oils for industry
• High erucic acid (industrial machinery)
• High palmitic acid (transgenic)
• High laurate acid (transgenic)
• In the future acids modified at particular
positions developed by genetic engineering.

8. Meal quality of rape seed
• Basically high value protein
• Anti nutritional compounds
– glucosinolates (reduces nutrient uptake,
especially with poultry) (two major recessive
genes)(maternal inheritance)
– sinapine (unpleasant smell with poultry)
– phytic acid (binds P in ingestible form)
– tannins (brown inhibitors from sead coat)

9. Yellow seeded rape seed
• Three recessive genes (all three should be
homozyogous to give yellow seeds)
• Less tannins
• Less fibers

10. Yellow seeded rape seed
• Three recessive genes (all three should be
homozyogous to give yellow seeds)
• Less tannins
• Less fibers