Species-specific SSR alleles for studies of hybrid cattails (Typha latifolia x T. angustifolia; Typhaceae) in North America

• Published in: American journal of botany 2010-12, Vol.97 (12), p.2061-2067
• Main Authors: Snow, Allison A, Travis, Steven E, Wildová, Radka, Fér, Tomáš, Sweeney, Patricia M, Marburger, Joy E, Windels, Steven, Kubátová, Barbora, Goldberg, Deborah E, Mutegi, Evans
• Format: Article
• Language: English
• Subjects: Alleles; Biomarkers; Botany; BRIEF COMMUNICATION; cattail; Ecological genetics; Ecological invasion; Evolution & development; Flowers & plants; gene flow; Gene loci; Genetic hybridization; Genetic loci; hybrid; Hybridity; Hybridization; introgression; invasive species; molecular markers; morphological traits; Plant populations; Plants; Polymorphism; Population ecology; species‐specific markers; STRUCTURE; Typha; Typha angustifolia; Typha latifolia; Typhaceae; Wetland ecology; Wetlands
• ISSN: 0002-9122; 1537-2197
• DOI: 10.3732/ajb.1000187

PREMISE: Studies of hybridizing species are facilitated by the availability of species-specific molecular markers for identifying early- and later-generation hybrids. Cattails are a dominant feature of wetland communities, and a better understanding of the prevalence of hybrids is needed to assess the ecological and evolutionary effects of hybridization. Hybridization between Typha angustifolia and T. latifolia produce long-lived clones, known as Typha xglauca, which are considered to be invasive. Although morphological variation in cattails makes it difficult to recognize early- and later-generation hybrids, several dominant, species-specific RAPD markers are available. Our goal was to find codominant, species-specific markers with greater polymorphism than RAPDs, to identify later-generation hybrids more efficiently. METHODS: We screened nine SSR (simple sequence repeat) loci that were described from populations in Ukraine, and we surveyed 31 cattail populations from the upper Midwest and eastern USA. Key results: Seven SSR loci distinguished the parent taxa and were consistent with known species-specific RAPD markers, allowing easier detection of backcrossing. We used linear discriminant analysis to show that F₁ hybrid phenotypes were intermediate between the parent taxa, while those of backcrossed plants overlapped with the hybrids and their parents. Log(leaf length/leaf width), spike gap length, spike length, and stem diameter explained much of the variation among groups. CONCLUSIONS: We provide the first documentation of backcrossed plants in hybridizing cattail populations in Michigan. The diagnostic SSR loci we identified should be extremely useful for examining the evolutionary and ecology interactions of hybridizing cattails in North America.