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The induction of polyploidy is a common technique to overcome the sterility of a hybrid species during plant breeding. For example, triticale is the hybrid of wheat (Triticum turgidum) and rye (Secale cereale). It combines sought-after characteristics of the parents, but the initial hybrids are sterile.
For example, homoploid hybridization is hybridization where the offspring have the same ploidy level as the two parental species. This contrasts with a common situation in plants where chromosome doubling accompanies or occurs soon after hybridization. Similarly, homoploid speciation contrasts with polyploid speciation. [citation needed]
Two species mate resulting in a fit hybrid that is unable to mate with members of its parent species. Hybrid speciation is a form of speciation where hybridization between two different species leads to a new species, reproductively isolated from the parent species. Previously, reproductive isolation between two species and their parents was ...
Factors like polyploidy events also plays significant factors for understanding the hybridization events (Example: an F1 hybrid of Jatropha curcas x Ricinus communis), [6] because these polyploids tend to have an advantage for the early stages of adaptation due to their expanded genomes.
Hybridization is an important means of speciation in plants, since polyploidy (having more than two copies of each chromosome) is tolerated in plants more readily than in animals. [ 80 ] [ 81 ] Polyploidy is important in hybrids as it allows reproduction, with the two different sets of chromosomes each being able to pair with an identical ...
Wheat origins by repeated hybridization and polyploidy (e.g. "6N" means 6 sets of chromosomes per cell rather than the usual 2). Only a few of the wheat species involved are shown. The goatgrass species involved are not known for certain. [6]
Nevertheless, in plants, hybridization is a stimulus for the creation of new species – the contrary to the situation in animals. [34] Although the hybrid may be sterile, it can continue to multiply in the wild by asexual reproduction, whether vegetative propagation or apomixis or the production of seeds.
In many diploid-polyploid complexes the polyploid hybrid members reproduce asexually while diploids reproduce sexually. [2] Thus polyploidy is related to the phenomenon called "geographic parthenogenesis" by zoologist Albert Vandel , [ 3 ] that asexual organisms often have greater geographic ranges than their sexual relatives.