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2020 Update: Anna M.’s Hybrid Compatibility Experiment

Echinacea pallida is a non-native species to the prairie of western Minnesota and E. pallida has the potential to out compete the native E. angustifolia. To learn more about this in 2020, we cross-pollinated E. angustifolia, E. pallida, and a E. angustifolia X E. pallida hybrid plant to assess interspecies compatibility. This experiment investigates the reproductive potential of E. angustifolia and E. pallida hybrids, of which may threaten native E. angustifolia preservation.

Since this was the first year that a hybrid plant flowered it was a great opportunity to investigate this question. On July 6th, 2020, seventy-six total hand crosses were completed to test mating compatibility. Three E. angustifolia and three E. pallida plants from Hegg Lake WMA were selected to serve as maternal plants in the experiment. Each treatment consisted of three crosses with pollen from the plant’s respective species, three crosses with the hybrid pollen, and three crosses with no pollen as a control. E. angustifolia and E. pallida pollen was collected from no less than three plants to reduce risk of self-pollination. Finally, pollen collected from each maternal plant was administered to the hybrid. The hybrid received nine crosses with three different E. angustifolia plants, nine crosses with three different E. Pallida plants, and three styles received no pollen as a control. The order of pollen administration was randomized across a designated row of styles.

Pollinator exclusion bags were used to limit exposure to pollinators. We later collected the heads from the hybrid, maternal E. angustifolia, and maternal E. pallida plants. In the winter, these heads will be x-rayed to assess seed set.

Start year: 2020

Location: Hegg Lake WMA, Douglas County, MN

Overlaps with:Echinacea hybrids–p7

Data/materials collected: The team collected 10 heads which will be randomized and x-rayed at the CBG.

The data sheet for the hybrid experiment is located at   ~Dropbox/teamEchinacea2020/annaMeehan/AnnaMeehanDataSheet063020

Experimental Plot 7 / Hybrid Project Update

Hey flog!

I wanted to make a post detailing my experiment this summer with hybrid Echinacea plants at Hegg Lake. As a student, it was my goal to design, execute, and analyze an experiment with Team Echinacea this summer. Because I’m interested in genetics, I wanted to create something that would connect inheritance with population control among Echinacea. With the help of some seasoned Team Echinacea members (Riley T and Mia S), I was able to construct an experiment that would study the reproduction potential of hybrid Echinacea, crossed between E. angustifolia and E. pallida.

In the history of experimental plot 7, two Echinacea plants have flowered. Most recently, a hybrid Echinacea flowered this spring. This allowed us to cross the hybrid’s pollen with a variety of E. angustifolia and E. pallida in the Hegg Lake area. In order to assess reproduction potential, styles were painted, pollinated, and later observed to look for shriveling. Although styles may shrivel for a variety of reasons, shriveling usually indicates reproduction. In the winter, we will assess the seed-set of these individuals to determine reproductive fitness.

When new species from non-prairie remnants are introduced to new areas, the risk of hybridization among plants of the same genus arises. E. pallida, which has shown to out-compete E. angustifolia in our experimental plots, therefore has the ability to pass on its genes through hybrids. If hybrids are able to reproduce, and continue to pass on E. pallida genes, the risks of genetic swamping increase. Therefore, over time, hybridization could eventually exterminate E. angustifolia from its native prairie.

A picture of me painting bracts for our hybrid crosses. Photo credit to Mia S!

In order to assess reproduction, we hand-crossed a variety of sample pollen with E. angustifolia, E. pallida, and hybrid Echinacea. In this experiment, a shriveled style is a sign of successful reproduction. Because Echinacea plants are not self-compatible, the reasons for a style not to shrivel could vary. Reasons could be that the hybrid was not compatible with this type of Echinacea, or because the specific Echinacea plants were incompatible due to inheritance patterns.

An example of hand-crosses from Shona Sanford-Long, 2012

Our sample size was also effected because only one hybrid Echinacea flowered this summer. In the end, we cross-pollinated our hybrid plant with three E. angustifolia plants, and three E. pallida plants. If more hybrids flower in the future, we will be able to expand our sample size and cross variety. For this reason, we hope to continue this experiment in the following summers if hybrids continue to flower.

Overall, we saw that hybrids were more compatible with E. angustifolia rather than E. pallida. While hybrid reproduction passes on E. pallida genes, a greater chance of reproduction with E. angustifolia keeps native genes (and hopefully, native traits) in the prairie gene pool.

In the future, I will share more updates as we continue to analyze and reassess the data.

Thanks for joining me on this exciting, new experiment!

Anna (Meehan)