7/18/2015: Saturday and compatibility project update


Can you guess who it is?

Ben Lee (2015); ballpoint pen on notebook paper

It was a good Saturday of phenology and fun for Team Echinacea! A group of us braved the morning fog and went out to our remnant sites to assess phenology. Lots of plants have reached or are nearing the end of their flowering time already. Later in the day we went swimming, played bananagrams, and drew blind contour drawings of each other.

This weekend, Danny and I have been working the ongoing project assessing compatibility between Echinacea individuals within remnants. On Friday, we went to Loeffler’s Corner and randomly selected 10 flowering plants; these are our focal plants. We do four crosses on each focal plant, with pollen from each of the crosses being placed on four or 5 bracts of the focal plants. We can tell if the cross is compatible by seeing if the styles shrivel after receiving pollen; if they do, they’re compatible, but if the styles persist, then the cross was between two plants that are not compatible.

For this study, we cross each focal plant with its nearest flowering neighbor, its furthest flowering neighbor, a plant that flowered early (i.e. one that is just ending flowering), and a plant that flowered late (i.e. one that just started flowering). To keep track of the crosses, we paint the bracts of the focal plant different colors which correspond to the cross that the style will receive: near, far, early, or late. We paint bracts corresponding to male florets; the next day, they will be styles, and we will be able to do the crosses. After we paint, we cover each focal flower with a pollinator exclusion bag so that we can be sure that no other pollen is introduced.

On the next day, Saturday, the styles of our focal plants emerged. We collected pollen from the various pollen donors and used a toothpick to perform the crosses, carefully placing pollen onto the styles identified by their painted bracts. We cover the focal flowers back up with the pollinator exclusion bags and wait one day to see if the styles shrivel.

This morning, Danny and I went back out to Loeffler’s to check on style shriveling. Here are the results!

  Compatible Incompatible Inconclusive
Nearest neighbor 9 1 0
Farthest neighbor 7 2 1
Early flowering 7 1 2
Late flowering 9 1 0


Here I’m considering a cross compatible if 75% or more of the styles shriveled, incompatible if 25% or less shriveled, and inconclusive if it is anywhere in between. We’ll go back tomorrow to check on crosses that weren’t either 100% shriveled or not shriveled and see if any more styles have shriveled in that time.

Hopefully we’ll be able to repeat this process on several more remnant populations this coming week!


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