Hybridisation
Process information from secondary sources
to describe an example of hybridisation and
explain the purpose of hybridisation
Hybridisation
LABRAGULL
APPOG
SQUIRAPPLE
Kevin Quigley. 2006.
Hybrids
• Involves cross breeding different varieties of the same
species to produce a new variety of the same species.
Bull Terriers are a breed of dog that originated from cross
breeding Bulldogs and Terriers.
• Hybrids occur regularly in nature as this helps increase
genetic variety. Generally hybrid plants are more
vigorous and higher yielding than their true breeding
parents.
Hybridisation
Kevin Quigley. 2006.
Hybrids cont.
• Hybrids are usually infertile. Although offspring can
develop, the chromosomes do not match sufficiently for
meiosis to occur.
Examples of Hybrids
• Different breeds of dog can successfully breed because
they are all of the same species. They appear different
because they have different alleles for many physical
characteristics.
• Often hybrids are produced in agriculture for commercial
purposes. E.g. Flowers may be crossed to produce
larger flowers, frost resistance, pest resistance or unique
colours.
Wheat Hybridisation in Australia
• Late 1800’s – Australian wheat quality was too poor to
make flour  Wheat was imported.
• Wheat varieties grown were all from England. They were
unsuitable for the Australian climate and had no
resistance to local plant diseases.
• William Farrer (1845 – 1906) pioneered Australian wheat
research. He commenced work on his farm in 1886.
William Farrer’s Work
• Farrer carried out artificial crosses of different wheat
varieties. He mainly used bread wheat (Triticum
aestivium) but also used some pasta wheat (Triticum
turgidum).
• Took an early-ripening Indian wheat and crossed it with a
good-baking Canadian variety
• He took this new hybrid and crossed it with a high yield
variety producing Federation
• He successfully bred wheat varieties with narrow leaves
to reduce water loss, early ripening, introduce resistance
to common diseases, improve baking quality and yield.
William Farrer’s Work, cont.
• Farrer’s new species could grow in drier conditions and
so were suitable for the Australian climate.
• Farrer is best known for a variety that became
commercially available in 1901 called ‘Federation’.
• Federation was a short growing, high yield, early ripening
wheat variety. Because of its’ height it was suitable for the
new mechanical harvesters.
• By 1910 Federation was the most widely grown wheat in
Australia.
• Farrers work continues today at the Sydney University’s Plant
Breeding Research Institute at Narrabri, NSW.
Hybrid Vigour
• This is also known as heterozygous vigour. It is the idea that
most hybrid organisms are often better suited to the
environment than the original organisms they were bred from.
• That is stronger, higher yields, live longer etc