Abstract Detail

Pollination Biology

Falconer, Denver [1], Cota-Sanchez, J. Hugo [2].

Reproductive biology in the Plains Prickly Pear, Opuntia polyacantha (Cactaceae), in Saskatchewan. Denver Falconer (denver.falconer@usask.ca) & J. Hugo Cota-Sánchez (hugo.cota@usask.ca). D.

Cacti found in Canada represent a very small group consisting of just four species, three of which are found in Saskatchewan. These species are able to withstand the cold winter temperatures and rejuvenate the following spring. Among these, Opuntia polyacantha Haw., is distributed from northern Mexico throughout the United States, eventually reaching western Canada. While this species is relatively common in the Prairie Provinces, little is known regarding its floral and reproductive biology. This study focuses on investigating the floral morphology, phenology, and breeding system of the species to explore the role of pollinators and sexual reproduction in the distribution of this species. Field studies were carried out ~25km south of Saskatoon, Saskatchewan, Canada. Flowers from three populations underwent different pollination treatments, including bagging (to determine breeding system) and morphological measurements. Fieldwork took place during the flowering season (beginning late June and finishing mid-July). Several conditions of pollinator exclusion, which were tested, indicate that this species is strongly reliant on pollinators, with a limited capacity for self-fertilization. The flowers also exhibit traits encouraging floral visitors, such as large, colorful perianth, large stigmatic surface, and numerous anthers. The flowers exhibit thigmonastic (sensitive) stamens: the filaments have a particular movement when exposed to external stimuli, which may aid pollination and protects the pollen. Nevertheless, populations are maintained mainly via asexual reproduction rather than by xenogamous methods. Further study will be carried out to better understand the reproductive biology of O. polyacantha.

1 - University Of Saskatchewan, Department Of Biology, Plant Systematics Lab, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada
2 - University Of Saskatchewan, Department Of Biology, 112 Science Place, Saskatoon, SK - Canada, S7N 5E2, Canada

Keywords:
Cactaceae
Opuntia
reproductive biology .

Presentation Type: Oral Paper:Papers for Topics
Session: 40
Location: Firs South/Boise Centre
Date: Wednesday, July 30th, 2014
Time: 2:15 PM
Number: 40004
Abstract ID:435
Candidate for Awards:None