Home/About
Glossary
Sections:
Introduction
Principles of inheritance
Genotypic variation
Other forms of heritable variation
Quantitative variation and heritability
Novel sources of genetic variation
The practice of plant breeding
Breeding methods
Breeding methods
Self pollinators: Mass selection
Self pollinators: Pure line selection
Self pollinators: Pedigree selection
The pedigree breeding funnel: wheat example
Self pollinators: Single seed descent and doubled haploid lines
Single seed descent
Single seed descent, contd
Doubled haploids
Self pollinators: Back-cross breeding
Self pollinators: male sterility and F1 hybrids
Manual emasculation
Chemical sterilization
Genetic male sterility
Cross pollinators: F1 hybrids
Cross pollinators: F1 hybrids, contd
Polyploids
Polyploids contd
Ploidy level affects fertility
Autopolyploid breeding
Alloployploid breeding
Vegetatively propagated crops
Tree crops
Participatory plant breeding
Plant Breeders' rights
New technologies for plant breeding
Untitled Document

Polyploids

Many important crop species are polyploid: cotton, wheat, banana, sugarcane, potato

There are two classes of polyploid:

autopolyploids have only one parent, but two or more times the number of chromosomes; examples are potato and red clover

allopolyploids have more than one parent and contain the full set of chromosomes from each of their parents; examples are cotton and bread wheat

triploids have three sets of chromosomes.
An AAA type is an autotriploid, AAB or ABC are allotriploids

tetraploids have four sets of chromosomes.
AAAA is an autotetraploid, AABB is an allotetraploid, etc.