Investigating the reproductive ecology of two native New Brunswick plants (Halenia deflexa and Lysimachia terrestris)

Abstract

The reproductive biology of native New Brunswick plants Halenia deflexa and Lysimachia terrestris are of interest as they are underrepresented in scientific literature and this research will inform our understanding of these angiosperms. While it is known that H. deflexa is self-compatible, it is unclear how its selfcompatibility effects its offspring. As well, the self-compatibility status of L. terrestris is currently unknown. This study aims to address these gaps in knowledge. To determine relative seed quality, 223 self- and outcross pollinated H. deflexa seeds were weighed. It was found that there was a borderline insignificant difference in mean seed mass between the two pollination treatments and a trend towards lower mass seeds in self-pollinated seeds. This suggests that self-pollinated seeds may be of lower quality. To determine the self-compatibility status in L. terrestris, 31 plants at the Sackville Retention Pond were emasculated and hand-pollinated with self or outcross pollen. While the self- and outcross pollination fruit sets were not statistically different, the results suggest that L. terrestris is self-incompatible. Additionally, the self-compatibility study prompted an investigation into L. terrestris sexual and asexual reproductive traits which revealed that there is spatial structure in the Sackville Retention Pond population. Overall, there are many aspects of H. deflexa and L. terrestris reproductive biology that we do not understand, but our research has shown that self-pollinated H. deflexa seeds may be of lower quality and that L. terrestris may be selfincompatible. Future studies should investigate the magnitude of inbreeding depression in self- and outcross pollinated H. deflexa, as well as potential causes for the spatial structure seen in L. terrestris reproductive traits.