Abstract Detail

Hybrids and Hybridization

Goodwillie, Carol [1], Stewart, Emily [2].

Implications of cleistogamy for hybridization between subspecies of Triodanis perfoliata (Campanulaceae).

Two subspecies of Triodanis perfoliata, a weedy annual species, provide an opportunity to explore the implications for hybridization of divergent allocation to cleistogamy. The subspecies co-occur throughout much of their ranges, and anecdotal evidence of hybridization has been reported. We quantified the extent of cleistogamy, hybridization and hybrid fitness at three sites of contact in eastern North Carolina. Morphological and genetic data from amplified fragment length polymorphisms provided congruent evidence for hybridization in plants sampled along transects spanning the contact zones. The incidence of hybrids differed among sites but was generally low, despite high hybrid fitness. STRUCTURE analysis suggested that backcrosses to subspecies perfoliata,which allocates more to chasmogamous flowers than subspecies biflora, were the most common hybrid type. We argue that the dominant expression of high chasmogamous flower production in F1 hybrids promotes backcrossing and therefore introgression to subspecies perfoliata. We present evidence that cleistogamy limits gene flow between the subspecies and, in a preliminary study,estimate the relative strength of this and other factors in preventing hybridization, including flowering phenology, habitat preference, and pollinator movement.

Broader Impacts:

1 - EAST CAROLINA UNIVERSITY, Department of Biology, Mail Stop 551, GREENVILLE, NC, 27858, USA
2 - East Carolina University, Biology Department, Howell Science Bldg., Greenville, NC, 27858

Keywords:
Triodanis
hybridization
cleistogamy
reproductive isolation.

Presentation Type: Oral Paper:Papers for Topics
Session: 22
Location: Rosedown/Riverside Hilton
Date: Tuesday, July 30th, 2013
Time: 9:30 AM
Number: 22003
Abstract ID:145
Candidate for Awards:None