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Karyotypic variation and pollen stainability in resynthesized allopolyploids Tragopogon miscellus and T. mirus
Author(s) -
Spoelhof Jonathan P.,
Chester Michael,
Rodriguez Roseana,
Geraci Blake,
Heo Kweon,
Mavrodiev Evgeny,
Soltis Pamela S.,
Soltis Douglas E.
Publication year - 2017
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.3732/ajb.1700180
Subject(s) - biology , pollen , variation (astronomy) , botany , evolutionary biology , astrophysics , physics
PREMISE OF THE STUDY: Polyploidy has extensively shaped the evolution of plants, but the early stages of polyploidy are still poorly understood. The neoallopolyploid species Tragopogon mirus and T . miscellus are both characterized by widespread karyotypic variation, including frequent aneuploidy and intergenomic translocations. Our study illuminates the origins and early impacts of this variation by addressing two questions: How quickly does karyotypic variation accumulate in Tragopogon allopolyploids following whole‐genome duplication (WGD), and how does the fertility of resynthesized Tragopogon allopolyploids evolve shortly after WGD? METHODS: We used genomic in situ hybridization and lactophenol‐cotton blue staining to estimate the karyotypic variation and pollen stainability, respectively, of resynthesized T . mirus and T . miscellus during the first five generations after WGD. KEY RESULTS: Widespread karyotypic variation developed quickly in synthetics and resembled that of naturally occurring T . mirus and T . miscellus by generation S 4 . Pollen stainability in resynthesized allopolyploids was consistently lower than that of natural T . mirus and T . miscellus , as well as their respective diploid progenitor species. Logistic regression showed that mean pollen stainability increased slightly over four generations in resynthesized T . mirus but remained at equivalent levels in T . miscellus . CONCLUSIONS: Our results clarify some of the changes that occur in T . mirus and T . miscellus immediately following their origin, most notably the rapid onset of karyotypic variation within these species immediately following WGD.