New allopolyploid plant species can arise by hybridization between two species. If hybridization occurs between a diploid plant species with 2n = 14 and a second diploid species with 2n = 22, the new allopolyploid would have 36 chromosomes. Is it likely that sexual reproduction between the allopolyploid species and either of its diploid ancestors would yield fertile progeny? Why or why not?

Key Concepts

Allopolyploidy

Allopolyploidy is a form of polyploidy that occurs when two different species hybridize, resulting in a new species with multiple sets of chromosomes from both parents. In this case, the allopolyploid plant species has a chromosome number of 36, which is the sum of the chromosome sets from its diploid ancestors. This genetic makeup can lead to unique traits and adaptations but also complicates reproduction with the parent species.

Chromosome Compatibility

Chromosome compatibility refers to the ability of two organisms to produce viable and fertile offspring based on their chromosome numbers and structures. In the scenario presented, the allopolyploid has 36 chromosomes, while its diploid ancestors have 14 and 22 chromosomes. This significant difference in chromosome number can hinder successful pairing during meiosis, often resulting in sterile offspring when hybridization occurs with the diploid ancestors.

Fertility in Hybrid Offspring

Fertility in hybrid offspring is influenced by the genetic compatibility of the parent species and the resulting chromosome pairing during reproduction. In many cases, hybrids between species with differing chromosome numbers are sterile due to improper segregation of chromosomes during gamete formation. Therefore, it is unlikely that sexual reproduction between the allopolyploid and its diploid ancestors would yield fertile progeny, as the mismatch in chromosome numbers can lead to infertility.