Undergraduate Research: S. americanus flowers, fertilization and crosses

Post by Mairead Willis, Senior Neuroscience and Behavior Major; Mairead was out of town during the poster session. She describes her work this past year here.

This year I got the chance to follow in the footsteps of Gregor Mendel. The McLachlan lab is working on a series of experiments with Schoenoplectus americanus. and wanted to know if it was possible to cross different individuals, or for them to fertilize themselves. Armed with Google, a greenhouse, a paper that a fellow student found (thanks, Erin!), and lots of help from everyone who works in the lab, I set out on a nine-month journey to make some baby plants.


Figure 1. S. americanus flower

The first thing I had to do was watch the flowers. I learned that the stigmata emerge before the anthers. I also learned that if the stigmata aren’t pollinated, the spikelet will sometimes extend to give the flower another shot at reproduction; the photo above shows a flower doing just that. Armed with that knowledge, I sheathed each new flower with a pollen bag, tied the bottom with string, and used a paintbrush to apply pollen from some flowers to the stigma of others. Then, I waited.

Figure 2. S. americanus seeds (see brown disks at the base of the flower)

In the first week of December, just before I was supposed to go home for winter break, eureka (was that a proper use of eureka?)! Fully formed seeds began to drop from the flowers I had pollinated, as well as some I hadn’t. The brown disks at the base of the flower in Figure 2 above are seeds. I left for break, thrilled and wondering how, exactly, one would germinate S. americanus seeds.

When I returned for the spring semester, I tried out one scientific method, one home-gardening technique, and one method proposed by grad student Megan to put the seeds in a state of mock dormancy for six weeks. At last, just before spring break, I was able to plant my seeds with help from Brady, who taught me how to set up a germination trial.

Figure 3. Germination! The white arrow points to the tiny green germinated plant.

When I returned from break, I couldn’t believe my eyes! You can’t really see them in Figure 3 above, but inside my germination pots were the cutest, sweetest little seedlings I ever did see. Do I anthropomorphize them? Absolutely.

Figure 4. Grown-up plant

Today was my last day in the lab, and I transferred the plants, still tiny, to grown-up pots in the greenhouse (Figure 4). This has been by far one of the most exciting and rewarding projects I’ve gotten to work on during my time in college, and I can’t thank Jason and Jody enough for letting me do it. To whoever has this job after me: Have fun and treat those plants right.


All my best,

Mairéad Willis

Class of 2018


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