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Spring is a hectic time for most biota; interns are no exception.
The lab currently has two undergraduate interns working on separate projects. Jill Pastick (Lakeforest College) is studying hybridization between native Echinacea angustifolia and non-native Echinacea pallida in Minnesota. This project began with Nicholas Goldsmith, who performed a hybrid crossing experiment in the summer of 2011 and observing pollination success based on style persistence. Shona Sanford continued his project by performing a second crossing experiment in the summer of 2012 and weighing achenes to determine whether or not they contained seeds. Jill is continuing the project by the germinating the achenes from Shona’s study to assess their survival and growth. She is currently photographing the seedlings to take detailed measurements on size and color.
Our other intern, Gia Hallaman (Northwestern), returned to the lab this week after spending her spring break volunteering on an organic farm in Wisconsin. She is in the process of curating and identifying ants collected by Jill Gall in the summer of 2012. Jill’s collection covered 6 prairie remnants throughout Douglas County Minnesota. So far, Gia has identified a subset of ants from all 6 sites. For her project, she is going to focus her effort on the Staffenson prairie preserve in order to compare the ant community in the burned and unburned units.
This week marks several milestones in the lab. First, the volunteers completed randomizing and weighing achenes from the 2011 harvest of a large experimental plot planted in 1999. This experiment looks for genetic differences among maternal populations by combining their offspring in a common environment and measuring a variety of traits, including seed set. Weighing is the last step in data collection for this experiment. Although we have a long way to go in processing 2011 data for other experiments, we are making good progress.
Another milestone this week is the launch of our new online data entry system for achene counts. Bianca Rosenbaum, the web developer at the Chicago Botanic Garden, has created an interface that allows volunteers log into the website, open scanned images, and enter data into a web form. In addition to doing away with paper datasheets, this will improve our ability to catch mistakes, such as mis-labeled scan files. Anne Coughlin was the first volunteer to try the new system.
In other news, intern Jill Pastick has begun the pre-germination phase for an experiment assessing the growth of Echinacea angustifolia x pallida hybrids. This will add to Shona Sanford’s work on style persistence and seed set of hybrid crosses. Click the link to read about Shona’s most recent findings on Echinacea hybrids: (https://echinaceaproject.org/wp-content/uploads/2013/02/more-work-with-e-angustifolia.html).
Every so often, an Echinacea seedling emerges with an extra cotyledon. I introduce to you, the tricot:
These are the seedlings from Jill Pastick’s experiment comparing Echinacea germination in agar vs. blotter paper. That picture was from last week (Feb. 19). Here is what they look like today (Feb. 27):
In other news, we are moving forward in developing an online data entry system for counting achenes. Stuart and I are beta-testing and Bianca, the CBG web developer, is refining the data management system. We will commence counting very soon.
We are in a quiet period before a marathon of Echinacea germination. Jill Pastick, the intern from Lakeforest College, is preparing an experiment to test different methods of germinating Echinacea achenes. In the past, we have germinated achenes on blue blotter paper placed in petri dishes. While this method has been successful, it has its disadvantages. For example, when seedlings emerge, their roots sometimes attach to the paper, leading to damage when they are removed from the petri dishes. Before we launch into germination for major Echinacea project experiments, Jill will explore the use of agar (a gel produced from algae) as an alternative to paper for germinating Echinacea achenes.
And, for your enjoyment, here is a scene from under the microscope. These ants are part of the collection that Jill Gall led this summer. In case you can’t tell, the one one the right is biting onto the antennae of the one on the left. I believe they are both Formica obscuripes.
This summer, REU student Jill Gall collected ants from prairie remnants in Douglas County. Part of her project was identifying specimens to genus and sorting them by morphospecies (i.e. you know they’re different species, but you don’t know which species they are). This fall I met with Dr. Sean Menke, an ant ecologist at Lakeforest College, to look at the specimens she collected and get advice about how to identify ants. His advice has helped me make move forward in identifying the specimens we collected this summer.
The challenge with distinguishing ant species is that a lot of the most obvious characteristics, such as size and color, vary within species. The traits that do distinguish species vary across genera. For instance, in the genus Formica, species can be discerned based on the hairs covering certain parts of the body and the glossiness of certain body parts. In Lasius, one of the key traits is the orientation of the hairs on the antennal scape (the part of the antenna closest to the head). With some genera, species identification is especially difficult. One of these is the genus Myrmica.
After looking through a large number of specimens, I have come across four types that I believe are separate species. The differences are in the shape of the antennal bend and in the shape of the flange that covers the base of the antennae. I have circled this area in the pictures below. For three of the four morphospecies, I have included pictures of two individuals. See if you can spot the differences.
15 January 2013 Amy Dykstra defended her doctoral dissertation, entitled: Seedling recruitment in fragmented populations of Echinacea angustifolia and passed with flying colors! Members of the committee referred to her research as extremely impressive and highly valuable to restoration biologists, among others. At the end of January, Amy will return to Bethel University, where she has been teaching since August 2011.
We are launching into the new year like an Echinacea achene launching from its receptacle. The reason I mention this terrible simile is that we are in the process of extracting achenes from Echinacea heads harvested in 2012. Even though we haven’t cleaned many heads, we have found quite a few stray achenes around the lab–on the floor, in drawer handles, in people’s clothes. One of our volunteers, Lou, developed a device to minimize achene loss. Lou is a mathematician and avid hobbyist engineer who has contributed his talents to various aspects of the project, including building a tray for scanning achenes and a frame for mapping and finding seedlings in the field. Volunteers Bill and Leslie tried out his prototype cleaning shield on Thursday and Friday:
In other news, we are in the process of developing a new system for collecting achene count data. Basically, instead of writing down the count on a paper data sheet, each counter would enter the information into an online form, which would feed directly into the database. Bianca Rosenbaum, the CBG web developer, is helping us develop this system. If all goes well, we should be able to try it out in the next few months.
There is a lot of work left to do for the 2011 Echinacea harvest, including counting achenes on scans and selecting a random sample to weigh. Thankfully, many of our volunteers have returned from holiday vacations and have resumed their invaluable work in the lab. For those that are still in warmer climes, we look forward to their return.
Today volunteers Bill and Bob spent the morning respectively cleaning and counting Echinacea achenes. Bill (pictured below) came across a receptacle that had a big hole in it–probably due to a burrowing critter:
In other news, Shona Sanford-Long, one of the 2012 summer REU interns, is here in the lab working on her Echinacea hybridization project. She spent the morning meticulously extracting achenes from the Echinacea pallida x angustifolia crosses she performed last summer.
David Lowenstein, a PhD student from University of Illinois at Chicago, came to the lab at the Chicago Botanic Garden in December to use our x-ray machine for his research project. One of the species he using in his project is Echinacea purpurea.
David x-raying a sample of Echinacea fruits (achenes).
Here’s what David had to say about his project…
I am studying pollinators in Chicago and whether vegetable crops and wild flowers in various neighborhoods in Chicago receive sufficient pollination. To investigate this, I used a mobile garden consisting of eggplant, cucumber, and purple coneflower. Potted plants of these species were transported to Chicago neighborhoods and left outside for four and half hours. I observed bee visits to focal plants, sampled the neighborhood floral community, and allowed the plants to mature under pollinator exclusion netting in the UIC greenhouse to measure pollination services. I measured pollination of purple coneflower by X-raying the achenes at the Chicago Botanic Garden and recording the proportion of full achenes from each Echinacea flowerhead. I found a positive relation between bee abundance and human population density, and I will use data from X-rayed achenes to determine if pollination services are also related to population density or other land cover variables. To read more about this project that will continue in summer 2013, visit http://www.uic.edu/labs/minor/urban_pollination.html
Here are three of his x-ray images. If you click & enlarge these images, you will see that some achenes are empty and others have embryos.
LFC students Marissa Ruiz and Courtney King created this fabulous poster using samples from my 2012 Helianthus experiment for my thesis. Indeed, we have significant support for the self-incompatibility of the genus.
Bio 384 poster final.pdf
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