What does allopolyploidy mean?
Allopolyploidy is the biological condition in which a cell or organism carries two or more complete sets of chromosomes that originate from different species. It typically arises when two related species hybridize and the resulting sterile offspring undergoes chromosome doubling, restoring fertility while retaining both parental genomes. The term is central to plant genetics and evolutionary biology because many major crops — including bread wheat, cotton, canola, and tobacco — are allopolyploids formed this way. Allopolyploidy is a powerful driver of speciation, instantly creating reproductively isolated lineages and often conferring hybrid vigor, broader ecological tolerance, and novel traits. It contrasts with autopolyploidy, in which all chromosome sets come from the same species. Used almost entirely in scientific contexts, the word conveys precision and technical authority, and it remains indispensable for describing how hybridization and genome duplication together shape plant diversity and agricultural history.
nounThe condition of a cell or organism having two or more complete sets of chromosomes derived from different species, typically arising through hybridization followed by chromosome doubling.
- The state of being allopolyploid: possessing chromosome sets derived from two or more distinct species, resulting from interspecific hybridization followed by genome doubling.
"Wheat owes its origin to successive events of allopolyploidy that combined genomes of wild grasses."
"Cotton's commercial importance stems from allopolyploidy, which united Old World and New World cotton lineages in one species."
"The researchers confirmed that speciation in the genus occurred through allopolyploidy rather than simple divergence."
Rarely pluralized in practice; the concept is usually treated as a single phenomenon per lineage.
"Multiple independent allopolyploidies shaped the evolution of the wheat group."
Bread wheat exists at all because ancient hybridization and genome doubling merged three wild grass species into one — a natural genetic engineering event called allopolyploidy.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of allopolyploidy
The word combines 'allo-' (from Greek allos, meaning 'other' or 'different'), 'poly-' (from Greek polys, meaning 'many'), and '-ploidy', which derives ultimately from Greek '-ploos/-plous' ('fold') via the term 'haploid'. It was coined in the twentieth century as cytogeneticists distinguished between polyploids whose chromosome sets came from one species and those assembled from different species. Its cognates include other terms built on the same Greek roots, such as diploid, haploid, and aneuploidy.
Related word forms
How allopolyploidy is actually used
A technical term used almost exclusively in genetics, botany, and evolutionary biology; rarely encountered outside scientific literature.
Easily confused with allopolyploidy
Autopolyploidy involves multiplication of chromosome sets within a single species, whereas allopolyploidy combines chromosome sets from different species.