Flowering phenology in experimental plots

First week and half in Minnesota

Hi all,
So I arrived up at the field site about a week and half ago to finish up monitoring flowering and help out with measuring and demo. Except for the recent death of my computer’s hard drive it has been an excellent start to my field season. As you may know flowering was about a week earlier this year with many more flowering heads than expected. I would have estimated around 800 (max) flowering heads but we had over 1,100 flowering in the common garden. Last year was also a huge flowering year (over 1,300 heads) because it was a burn year. I am excited to now have two years of flowering data on a large of plants in the common garden.

We have spent a large part of the last week I have been here measuring both in the common garden and at the hegg lake common garden. The hegg lake common garden was established back in May of 2006 to as part of my graduate research. It is about 6 miles from the main common garden on Minnesota DNR land. It has around 4,000 plants planted on a 1m X 1m grid. Today we had the entire field crew out at hegg lake measuring for a total of 13 people and measured nearly half of the entire plot just today…it was great!

Besides the field work I have been keeping myself busy in rural Minnesota by fishing (Ian has promised that I will actually know how to fish by the end of the summer), playing poker, and going to a dirt track race. In the near future I plan on flogging all non-Echinacea related activities that can be done in rural Minnesota….however now I’m tired so it will have to wait until the weekend.
Night!
Jennifer

Ants in my pants (and by in my pants, I mean on my mind)

In general, the two main differences between ’99 South and the main common garden (for damage assessment and herbivory) appears to be less damage in ’99 South and more ants (and less ant diversity).

When doing phenology in the ’99 common garden about a week ago I noticed that the plants in the eastern-most row (those along the very edge) appeared to be more likely to have ants and (very anecdotally) seemed to have a different amount of florivery damage and browning than the rest of the garden (it’s been too long owing to my laxness in flogging and I can’t remember if it was less or more, though I am inclined to say less). Whether there actually is a difference in damage and whether this difference results from ants, edge effects, or chance remains to be seen.

A few days ago when I was doing phenology in the ’99 South common garden I noted that the majority of plants in the garden had ants and that there was low variability in ant species composition – virtually all I saw where the large black ones with red heads. These ants were very aggressing and would leap off the flower head onto my stylus as I was pointing at the anthers to count them. I could practically hear them sharpening their mandibles. The northern-most row (those along the very edge) had few ants and the ants were of different species, including small black ones and light-colored ones. Interestingly, there was much more damage in this row.

Are these large ants actively defending their flower heads and increasing plant fitness?

Do other species of ants contribute less to the echinacea in terms of defense? Do they take more away in terms of pollen and nectar? It is not uncommon to see ants covered/dusted in pollen (I never observed this of the large black species) and I have twice seen a small black ant actively carrying pollen in its mandibles.

Microsatellites in Echinacea… they do exist

Hello all,
So this is my very first blog entry so it will be lacking all the neat links to pictures et al in that are in other people’s entries but it will talk about Echinacea.

Since this is my first blog I should probably spend a little time introducing myself. My name is Jennifer I am a in an inter-disciplinary PhD program, called LEAP, at the University of Illinois at Chicago in conjunction with the Chicago Botanic Garden. LEAP stands for Landscape Ecological and Anthropogenic Processes, it is an NSF funded IGERT program aimed at increasing biodiversity in human altered landscapes. For a much better description of LEAP see http://www.uic.edu/depts/bios/leap/. As for the Echinacea Project I have been involved with the project first as an intern back in 2003-2004 then as a graduate student (since summer 2005). My research mainly focuses on understanding how flowering phenology (when a plant flowers) shapes seed set, pollen movement, and ultimately genetic structure in a population. For more see my website at http://www2.uic.edu/~ison/.

To understand how flowering phenology shapes population structure we use a variety of methods. First we collect phenology data in the common garden. The current protocol has us counting anthers shedding pollen every other day. We then collect the seed heads in the fall and individually weigh a subset of the seeds to get an estimate of seed set. Why individually weigh seeds? Well it is the only non-destructive method of determining if an achene (the technical term for fruits in the Asteraceae) actually has a viable embryo. We know that 97% or seeds weighing greater than 2 mg will germinate and 91% of less weighing less than 2 mg will not germinate. As of this spring we have individually weighed (with the help of an amazing volunteer named Art) weighed 30,211 seeds. This June Art has embarked on weighing another 3,000 seeds from the 2006 flowering plants. So far we know that late flowering plants set much less seed than early or peak flowering plants. To get at the hereditability of flowering phenology we planted a second common garden (yes there is another common garden) on a site called Hegg Lake owned by the DNR. The site was planted with just about 4,000 seedlings in May 2006 and the plants will hopefully flower before I finish my PhD.

Finally, to understand how flowering phenology influences pollen movement we are using molecular genetic techniques, specifically microsatellites markers. Microsatellites are a molecular genetic marker that consist of repeating non-coding regions in the genome (eg GATGATGATGAT). Since they are repeating non-coding regions they mutate relatively rapidly so there are different number of repeats for the same microsatellite in a population–alleles. With these microsatellites we will be able to, eventually, take a seed from a known maternal plant and find out who the dad is. I developed microsatellites specifically for Echinacea last fall at the Field Museum of Natural History in Chicago. I now need to determine of these microsatellites I found do they actually have enough alleles to conduct paternity analysis. While everyone else has been up in Minnesota flying kites I have been spending time in the genetics lab trying to get the microsatellites to work. After spending too long figuring out the optimal number of cycles and temperature in the PCR, plus how much, if any, Mg to add I finally have been having success with about 5 microsatellites.

Today I ran four out of the five primers on 16 plants (8 from the preserve and 8 from Steven’s approach) and had multiple alleles!!! I had between 4 to 6 alleles just in these 16 plants. It was very exciting after spending so long playing with PCR conditions. It was very rewarding to run samples that actually worked and even better that all the microsatellites were at least moderately variable. My goal is to get 8 primers with all with around 6 alleles, which should be enough to do figure out who the dad is. For my next blog entry I’ll see if I can figure out how to add pictures and I’ll insert some images of my microsatellite alleles.

I think that is more than enough for my first entry. I will hopefully have more exciting news regarding the microsatellites before I come up to Minnesota (which is on July 15th).
Night!
Jennifer

Notes to self:
Equipment for MN
-2 meter sticks
-camera
-data logger (?)–talk to JF
Finish up at CBG
-put seeds into freezer–talk to AS?
-data entry for Theresa
-get tissue samples into fresh silica gel
-molecular work for John and Eric

More data to collect tomorrow and reminders….

Dearest floggers:

Well, it is 7am on my day off, but I can’t stop thinking about science and the possibilities to learn more about how Echinacea fares in the rich community we have in the common garden. Florid, yes, but I am pretty excited about possible data. It is like gold.

Truly, there are tons of projects to do, but the trick is to find the ones that:

1) Can be done in a timely manner,
2) Are interesting and important in advancing our knowledge about Echinacea and prairie plants in general,
3) Are educational for the students (and researchers!),
4) Can be repeated well into the future of the CG or remnants, and
5), Have a good chance of filling a gap in the literature so they can be published in good journals (this, of course, is related to #2).

This last point is not crucial in the moral sense, but crucial in the practical sense, as papers are the currency of our profession, as my advisor, Rick Karban, once told me.

Anywho, as we do phenology every other day it occurred to me that we could also quantify the percentage of ray florets with herbivore damage at the same time. Perhaps some genotypes accrue damage faster than others…I’m not sure if many researchers have looked at florivory over time in such detail. There seems to be quite a bit of damage this year. I did some ‘quick and dirty’ sampling last year, but did not have the plant IDs recorded, DOH , oh well, live and learn.

We also have to figure out how to measure fluctuating asymmetry (FA) so that we have multiple measurements to account for measurement error. Measurement error is important to quantify because the small deviations from symmetry that we may observe may smaller in magnitude than our error, but we can’t know unless we have replicate measurments! One way to do it is to take several pictures of the same plant, perhaps by different people. Or, you could have several people measure the same plant. Also, I wonder if FA changes with phenology or with organ under consideration…

Stuart and I are going to try and run electrical cord from the granary to the CG so that we can run the videocameras for a good long time each day. It is 120m from the granary to the SE corner of the garden, so this will take lots of cord to complete. Since I know very little about electrical wiring, save that you shouldn’t stick live wires into tubs of water, I will wait until Stuart gets some advice in Chicago before diving in.

BTW, I took video of the biggest plant in the CG yesterday and didn’t see any pollinators in 90 minutes of filming, so perhaps an even longer interval would be better to get good, non-zero data.

Signing off until this afternoon. I never knew I would like blogs, but they are useful, especially if people read them (hem hem)

Reminders:

We should measure style persistence as a measure of pollen limitation when we can (perhaps on Tuesday). Also, damage to ray florets would be excellent to measure. I wonder if damage to ray florets has greater indirect effects through reduced pollination than the direct damage to styles that we have seen?!

😉 Andy

Categories

Experiments

First week and half in Minnesota

Ants in my pants (and by in my pants, I mean on my mind)

Microsatellites in Echinacea… they do exist

More data to collect tomorrow and reminders….

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