Abstract Detail

Conservation Biology

Handley, Joy [1], Tronstad, Lusha [1].

Pollination and seed-set of Desert yellowhead (Yermo xanthocephalus).

Desert yellowhead (Yermo xanthocephalus) is a Wyoming endemic, known from two populations in central Wyoming, and is listed Threatened under the U.S. Endangered Species Act. Rare plants often have specialized pollinators and the abundance of these pollinators can regulate the reproductive success of such plants. During the 2018 field season, we investigated the degree to which Desert yellowhead was pollen-limited by recording the number and mass of seeds produced in hand-pollinated (unlimited pollen), open (insect pollinated) and bagged (pollen excluded) blooms in both populations. Additionally, we used Tetrazolium staining to estimate the viability of seeds produced in all treatments. The number of seeds did not vary among treatments or between populations, and may be constrained by genetics. However, the mass of seeds varied among treatments and between populations. The mass of seeds from the Cedar Rim population did not vary among treatments and none of the seeds were viable. Seeds in the unlimited pollen and insect pollinated treatments from the Sand Draw population had significantly higher mass than the pollen excluded seeds. At Sand Draw, only 14-16% of the pollinated seeds were viable, while less than 7% of the seeds in the pollen excluded treatment were viable. Pollinators do not appear to limit seed production in Desert yellowhead because the mass of seeds in the open and hand-pollinated treatments did not differ. Understanding what limits seed production will help manage the perpetuation of this rare plant.

1 - University of Wyoming, Wyoming Natural Diversity Database, Dept. 3381, 1000 E. University Avenue, Laramie, WY, 82071, USA

Keywords:
pollen
pollinator
seed viability.

Presentation Type: Poster
Session: P, Conservation Biology Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PCB005
Abstract ID:334
Candidate for Awards:None