A simple method to genetically differentiate invasive F1 Typha hybrids (T. × glauca) and advanced-generation/backcrossed hybrids from parent species (T. Latifolia and T. angustifolia) in eastern Canada and northeastern USA

Abstract

A widespread Typha (cattail) hybrid zone in southeastern Canada and northeastern USA comprises T. latifolia, T. angustifolia, and their hybrid T. × glauca. In this region the hybrid is considered invasive because of its detrimental impacts on wetlands and biodiversity. Researchers and managers are increasingly interested in tracking and controlling the spread of the invasive hybrid, but this can be hampered by challenges in differentiating taxa: while the parent species and F1 hybrids can often be identified from morphological characteristics, advanced-generation and backcrossed hybrids can be common, and these have obscured morphological distinctions among taxa. Here we present five species-specific genetic markers that differentiate T. latifolia, T. angustifolia, F₁ hybrids, and advanced-generation/backcrossed hybrids. Unlike the pre-existing species-specific microsatellite markers, these markers require only PCR or PCR followed by a restriction enzyme digest, and can be visualized on an agarose gel. As a result, they require less specialized equipment than existing species-specific markers, and should therefore be useful for a larger group of practitioners. Future use of these markers could include monitoring range expansions, assessing the outcomes of restoration programs, and avoiding the unnecessary elimination of native Typha.