Orchids, and Hawk Moths, and Inbreeding, Oh My!

I'm beginning my third week as an REU intern at the Chicago Botanic Gardens and so far I am loving everything about working here. The first week here was mainly an introductory week where we met our mentors, took classes with the Conservation Land Management program where we learned about the flora of the west as well as monitoring and inventory techniques, and ended the week by attending a symposium about large-scale ecosystem restoration efforts. It was awesome getting to learn more about the efforts being made all over the U.S. to help conserve our land and made me very excited to start working on my own project.

For my project I am working under mentors Claire Ellwanger and Jeremie Fant, and alongside a fellow intern, Dionna Bidny, to determine the restoration impacts on the federally threatened Eastern Prairie Fringed Orchid (Platanthera leucophaea). Originally, the project was mainly focused on looking at the genetic diversity between the populations of this year's bloom and from stored DNA samples taken in 2000 to determine if hand breeding has raised the levels of inbreeding and led to inbreeding depression, however last week we were given the opportunity to design our own hypothesis and now will be looking at a couple of other questions.

We know that inbreeding depression leads to lower levels of fitness and so we wanted to be able to measure fitness to see if there is a relationship between levels of fitness and population sizes. In order to do this we will be going out to many of the sites here in Illinois to measure the morphological characteristics of the flowers and will also be collecting leaf samples for our genetic analysis. We hope to also be able to compare these measurements with measurements taken over the years to see if there is also a relationship between levels of fitness and time. 

Due to habitat loss and fragmentation, it has been thought that the eastern prairie fringed orchid's known pollinator, Sphinx eremitus, is no longer able to pollinate between many of the sites. Therefore, for our second question, we wanted to look and see if there is a relationship between the fitness levels of P. leucophaea and presence (or absence) of this hawk moth. We will look for evidence of the hawk moth's presence by observing the undersides of host plants in the vicinity of the orchids and will look for eggs and larvae. We will also hopefully have the opportunity to set up black light trappings to observe the abundance of pollinators at each population site. 

hawk moth.jpgSphinx eremitus

To bring all of our findings together, we will also be looking at the genetic diversity of P. leucophaea by extracting DNA from old leaf samples, as well as leaf samples from this year's bloom, and running microsatellites to determine the genetic diversity of the populations. We will then see if there is a relationship between genetic diversity, levels of fitness, and presence or absence of the pollinator. We have a pretty large project ahead of us, but I am very excited for the diverse work that we will be doing and would like to continue following this project even after I leave this summer. And this week should be pretty awesome because the flowers have started to bloom so we should be able to start going out to the sites! I can't wait to see the this cute little orchid in person! :)