polyploid

[kyros]

some plant organisms give offspring with multiple number of chromosomes. for exmple, plants with 28
chromosomes may give very few viable and fertile offspring with 56
chromosomes.
These young plants belong to the same species as their ancestors?

[plasmodesmata11]

it would seem so because the offspring would be reproductively isolated from its diploid parental species. but then there's always the foggy line of what defines a species....

[JackBean]

yeah, they belong to the same species, but often have improved properties

[kyros]

in school i have learned that there are 2 criteria of species division mixiologic and typological(i don't know if the translation of the definitions)mixiological criterion requires that 2 organisms can ''mate'' and give fertile offspring to be classified among the same species.can a plant with polyploid reproduce with a ''normal'' plant and give fertile offspring??isn't there any problem with the extra chromosomes of the polyploid plant at the gamete combination??
as for the typological criterion requires that 2 organisms just resemble to be classified among the same species,but it used mainly for microorganisms that reproduce by dividing and not by gamete making and combining.
i am a little bit confused....

[robsabba]

in school i have learned that there are 2 criteria of species division mixiologic and typological(i don't know if the translation of the definitions)mixiological criterion requires that 2 organisms can ''mate'' and give fertile offspring to be classified among the same species.can a plant with polyploid reproduce with a ''normal'' plant and give fertile offspring??isn't there any problem with the extra chromosomes of the polyploid plant at the gamete combination??
as for the typological criterion requires that 2 organisms just resemble to be classified among the same species,but it used mainly for microorganisms that reproduce by dividing and not by gamete making and combining.
i am a little bit confused....

The definition of a "species" is not simple, because nature does not create "species." Keep in mind, however, that polyploid individuals do not have different chromosomes compared to diploid individuals. They just have extra "sets" of chromosomes.

[JackBean]

kyros: IMHO depends on how much ploidy is the plant. If is it tetraploid, the offspring would be triploid a thus should be sterile. However, if it was hexaploid, the offspring should be tetraploid and thus now problem...