Karyotypic variation and pollen stainability in resynthesized allopolyploids Tragopogon miscellus and T. mirus. Issue 10 (24th October 2017)

• Record Type: Journal Article
• Authors: Spoelhof, Jonathan P.; Chester, Michael; Rodriguez, Roseana; Geraci, Blake; Heo, Kweon; Mavrodiev, Evgeny; Soltis, Pamela S.; Soltis, Douglas E.
• Is Part Of: American journal of botany. Volume 104:Issue 10(2017)
• Page Start: 1484
• Page End: 1492
• Publication Date: 2017-10-24
• Subjects: Aneuploidy -- Asteraceae -- chromosomal translocation -- genome duplication -- genomic in situ hybridization -- neopolyploidy -- pollen -- Tragopogon; Botany -- Periodicals; Botany; Electronic journals; Periodicals; 580
• DOI: 10.3732/ajb.1700180
• Languages: English
• ISSNs: 0002-9122

Abstract

Abstract : 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 S4 . 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.