Relating to a hybrid individual or cell with two or more sets of chromosomes derived from two different ancestral species; depending on the number of multiples of haploid sets, alloploids are referred to as allodiploids, allotriploids, allotetraploids, allopentaploids, allohexaploids, etc.heterokaryon. [allo- + -ploid]

Alloploid refers to a type of polyploidy, a condition in which an organism has more than two sets of chromosomes in its genome. In alloploidy, the additional chromosome sets come from related but distinct species that have hybridized to form a new organism. This is in contrast to autopolyploidy, where an organism has multiple sets of chromosomes that are derived from within the same species.

Alloploidy can occur naturally or be induced through artificial means, such as plant breeding. For example, bread wheat (Triticum aestivum) is an alloploid species that originated from the hybridization of three different diploid grass species. The resulting hybrid had six sets of chromosomes, which eventually evolved into the modern-day bread wheat.

Alloploidy can have important implications for the evolution and ecology of species. The incorporation of additional chromosome sets can lead to the creation of new traits, increasing genetic diversity and potentially leading to adaptive advantages. On the other hand, the genetic incompatibilities between the parental species can lead to problems in the offspring, such as infertility or developmental abnormalities. Therefore, alloploid hybrids may require specialized breeding programs or be sterile, limiting their potential as crops or in other practical applications.