Phenotypic, genetic and genomic consequences of natural and synthetic polyploidization of Nicotiana attenuata and Nicotiana obtusifolia

摘要

Background and Methods Polyploidy results in genetic turmoil, much of which is associated with new phenotypes that result in speciation. Five independent lines of synthetic allotetraploid N. × obtusiata (N × o) were created from crosses between the diploid N. attenuata (Na) (♂) and N. obtusifolia (No) (♀) and the autotetraploids of Na (NaT) and No (NoT) were synthesized. Their genetic, genomic and phenotypic changes were then compared with those of the parental diploid species (Na and No) as well as to the natural allotetraploids, N. quadrivalvis (Nq) and N. clevelandii (Nc), which formed 1 million years ago from crosses between ancient Na and No.