allopolüploizi

Allopolyploidy is a biological phenomenon where an organism acquires one or more complete sets of chromosomes from two or more different species. This differs from autopolyploidy, where an organism duplicates its own chromosome set. Allopolyploidy typically arises through hybridization between two distinct species, followed by a doubling of the chromosome number in the hybrid offspring. This doubling event is crucial because it restores fertility to the hybrid, which would otherwise be sterile due to mismatched chromosomes that cannot pair properly during meiosis.

The resulting allopolyploid organism contains a complete diploid set of chromosomes from each of its parent species. For example, if species A has 2n chromosomes and species B has 2n chromosomes, their hybrid would be diploid (n from A and n from B). If this hybrid undergoes chromosome doubling, the allopolyploid would have 2n chromosomes from species A and 2n chromosomes from species B. This new genetic combination can lead to novel traits and characteristics, often conferring advantages such as increased vigor, adaptability, or resistance to disease.

Allopolyploidy is a significant evolutionary mechanism, particularly in plants, where it has played a major role in the diversification of species. Many common crops, including wheat, cotton, and tobacco, are allopolyploids. The process can occur naturally or can be induced experimentally by treating hybrids with specific chemicals that inhibit cell division after chromosome replication. The study of allopolyploidy is important for understanding plant breeding, speciation, and the evolution of genomes.