Phylogenies constructed with multiple accessions of diploid parentals and
allotetraploids can show multiple origins if several accessions of a polyploid appear more closely related to separate accession from one or more of the parental (Soltis & Soltis 1999).
Molecular linkage map of
allotetraploid cotton (Gossypium hirsutum L.
Johnson and Johnson (2006) first demonstrated that Collomia biflora was an
allotetraploid using evidence from nuclear idhA and idhB genes.
It is speculated that
allotetraploid cotton became a host of CLCuD after polyploidization where susceptibility genes were provided by wild species belong to D genome.
Only two taxa have been proposed to have
allotetraploid origins.
Traditional breeding has generated improved drought-resistant forage species by combining genes from closely related species, for example, the
allotetraploid hybrid between L.
truncatus is an
allotetraploid species and that in such species the genetic load is expected to be lower than in diploid species (Lande and Schemske 1985), though a thorough theoretical analysis has still to be performed.
Spore fitness components do not differ between diploid and
allotetraploid species of Dryopteris (Dryopteridaceae).
ciliatus is an
allotetraploid but no genome designations were made.
This species also displays cytotype variations, especially with the presence in the Middle Atlas of at least one
allotetraploid population.
Amsinckia gloriosa is almost certainly an
allotetraploid, as it displays disomic inheritance at the one variable electrophoretic marker locus in each population and is a fixed heterozygote at many of the other markers.
Soybean is considered to be a stable
allotetraploid with diploidized genomes (2n = 4x = 40) (Singh and Hymowitz, 1988).
