Zaya, David , Leicht-Young, Stacey , Pavlovic, Noel , Ashley, Mary .
Asymmetric pollen flow between a native and introduced vine (Celastrus spp.).
The threat that introduced plant species pose to native biodiversity through competition and habitat alteration is widely recognized, but the threat of hybridization with native congeners has only recently gained attention. Hybridization is especially detrimental when asymmetric pollen flow occurs, when more pollen flows from the introduced species to the native than vice versa. American bittersweet (Celastrus scandens) and Oriental bittersweet (C. orbiculatus) are both vines found in the eastern United States, where C. scandens is native and C. orbiculatus was introduced in the late nineteenth century. Genetic analysis has confirmed the presence of hybrids in the wild, but in order to determine the rate of hybridization and directionality of pollen flow we conducted manipulative hand-crosses in the field and observations of flower fate on both vines. Results from manipulative hand-crosses demonstrated that American bittersweet is significantly more likely to accept pollen from Oriental bittersweet than vice versa. The observational study and germination trials demonstrated that American bittersweet pistillate plants have a lower flower fertilization rate and a greater hybridization rate, and the two rates are correlated with proximity of staminate congeners. Asymmetry in pollen flow is likely due to differences in recognition and rejection of interspecific pollen, and a large advantage of Oriental bittersweet in terms of staminate floral output. This work demonstrates the importance of eradicating Oriental bittersweet at the early stages of invasion, before hybridization can threaten the fecundity and genetic identity of American bittersweet populations.
Log in to add this item to your schedule
1 - University Of Illinois At Chicago, UIC Biological Sciences, M/C 066, 845 W. Taylor, Chicago, IL, 60607, USA
2 - United States Geological Survey, Great Lakes Science Center, Lake Michigan Ecological Research Station, 1100 N. Mineral Springs Rd, Porter, IN, 46304, USA
3 - U.S. Geological Survey, 1100 N Mineral Springs Rd, Porter, IN, 46304, USA
4 - University Of Illinois At Chicago, 845 W. Taylor St., Chicago, IL, 60607, USA
Presentation Type: Oral Paper:Papers for Sections
Date: Monday, July 9th, 2012
Time: 9:00 AM