2016 update: Heritability of fitness–qGen2 & qGen3

Alex and Lea measure qGen2 seedlings with much enthusiasm.

Alex and Lea measure qGen3 seedlings with much enthusiasm.

The main goal of the qGen2 and qGen3 experiments is to quantify the evolutionary potential of two remnant prairie populations of Echinacea angustifolia by estimating the additive genetic variance of fitness. We make estimates for two mating scenarios. The first scenario is an experimental crossing design with all matings among plants from two “core” sites: SPP and LF (core x core). The second design uses sires (pollen donors) from the core and dams from sites peripheral to the core. The crosses performed (core x core, core x periphery) in this experiment will quantify additive genetic variance for fitness in each site and each experimental group. Additionally, we will test for differentiation among families; do progeny from sires differ after accounting for maternal (dam) effects?

In 2016, we found 1724 two year old plants out of the 2581 locations where plants had previously been found for the qGen2 cohort and 644 seedlings in the qGen3 cohort.

Comparing germination between the qGen2 & qGen3 cohorts:

exp approxFullAcheneCt totalAcheneCt seedlingCt germination
qGen2 6300 26144 2581 41%
qGen3 6200 19777 644 10%

Our crossing success, measured by the proportion of full achenes to total achenes crossed, increased in qGen3 (31%) compared to qGen2 (24%). While we planted approximately the same number of full achenes in the qGen2 & qGen3 cohorts, the germination rate was 4 times greater in qGen2 (41%) compared to qGen3 (10%). This difference was likely due to differences in environmental conditions. The Spring of 2016, was quite dry and probably tough on Echinacea seeds and sprouts.

Start year qGen3: 2015

Start year qGen2: 2013

Location: exPt 1 (dams), remnants Landfill and Staffanson (sires), remnants Landfill (core) & around Landfill (peripheral) and remnants Staffanson (core) & railroad crossing sites (peripheral) (grand-dams), exPt 8 (progeny)

Overlaps with: Heritability of fitness–qGen1

Data collected: We used handheld computers to collect data on seedlings and juvenile plants.

You can find more information about Heritability of fitness–qGen2 & qGen3 and links to previous flog posts regarding this experiment at the background page for the experiment.


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