Abstract Detail

Ecological Section

Závada , Tomáš [1], Kesseli, Rick [2].

After Moby Dick – examining hybridization between Centaurea maculosa (Spotted Knapweed) and Centaurea jacea (Brown Knapweed) on Nantucket Island.

The current flora of New England consists of approximately 3,000 vascular plants; about a thousand are non-native plant species, 200 of which can be considered invasive. Centaurea maculosa (Spotted Knapweed) and Centaurea jacea (Brown Knapweed) are members of the Compositae family (Asteraceae) and natives of Eurasia. C. maculosa is a major invasive plant in North America, dominating large stretches of grassland.  Both species were introduced to Nantucket Island in early 1900s, based on herbarium collections. There have been observed and collected potential hybrids of C. maculosa with C. jacea. Hybridization can be detected from morphological intermediates, but must be confirmed with DNA analysis to exclude phenotypic plasticity.  We used chloroplast DNA sequence data and microsatellites to confirm potential hybridization between these species, and describe invasion history and genetic diversity of these weeds on Nantucket Island.  Presented results will clarify whether gene flow and hybridization between C. maculosa and C. jacea have produced the hybrid-like weeds, or if these plants represent environmental plastic morphs of  C. jacea.

1 - University Of Massachusetts, Biology, 100 Morrissey Blvd., Boston, MA, 02125, USA
2 - University Of Massachusetts, Biology, 100 Morrissey Blvd, Boston, MA, 02125, USA

Keywords:
invasive species
hybridization 
Phenotypic plasticity
Centaurea maculosa
Centaurea jacea
Compositae.

Presentation Type: Oral Paper:Papers for Sections
Session: 10
Location: Firs South/Boise Centre
Date: Monday, July 28th, 2014
Time: 2:30 PM
Number: 10005
Abstract ID:662
Candidate for Awards:Ecological Section Best Graduate Student Paper