allopolyploidiaan

Allopolyploidy refers to a type of polyploidy where an organism contains more than two sets of chromosomes, and these chromosome sets are derived from different species. This phenomenon occurs when two different species hybridize, and then the chromosome number of the resulting hybrid is doubled. For example, if species A has 2n chromosomes and species B has 2n chromosomes, their hybrid would typically be diploid (n from A + n from B = 2n). However, if the chromosome number of this hybrid doubles, it becomes an allopolyploid with 4n chromosomes, containing two sets from species A and two sets from species B.

Allopolyploidy is a significant mechanism in plant evolution, leading to the formation of new species with novel traits. The doubled chromosome sets in an allopolyploid are usually homologous but not identical, meaning they originated from different ancestral species. This genetic diversity can result in increased vigor, adaptability, and fertility compared to the parental species. Many important agricultural crops, such as wheat, cotton, and tobacco, are allopolyploids. The process can restore fertility to sterile hybrids by providing complete sets of chromosomes from each parent, allowing for proper pairing during meiosis. Allopolyploidy is distinct from autopolyploidy, where the extra chromosome sets originate from the same species.