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2016 update: Pollen addition and exclusion

Most of the surviving plants in the 1996 cohort of the common garden were basal this year

We observed that 95% surviving members of the 1996 cohort were basal in 2016

Does receiving the maximum amount of pollination vs. no pollen at all affect a plant’s longevity or likelihood of flowering in subsequent years? In this experiment we assess the long-term effects of pollen addition and exclusion on plant fitness. In 2012 and 2013 we identified flowering E. angustifolia plants in experimental plot 1 and randomly assigned one of two treatments to each: pollen addition or pollen exclusion. When plants flower in subsequent years they receive the same treatment they were originally assigned.

Across all experiments, 2016 was a low flowering year. Only four plants flowered of the 29 plants remaining in the pollen addition and exclusion experiment. We continued experimental treatments on these plants and recorded fitness characteristics.

Start year: 2012

Location: Experimental plot 1

Physical specimens: We harvested four flowering heads from this experiment that will be processed with the rest of the experimental plot 1 heads to determine achene count and proportion of full achenes. The labels for these heads, beginning with the letter “p,” identify them as part of the pollen addition and exclusion experiment.

Data collected: We recorded data electronically as part of the overall assessment of plant fitness in experimental plot 1. We recorded dates of bagging heads and pollen addition on paper datasheets.

You can find more information about the pollen addition and exclusion experiment and links to previous flog posts regarding this experiment at the background page for the experiment.

2016 update: Echinacea pallida flowering phenology

E. pallida heads are easily distinguished from E. angustifolia by their white pollen and longer ray florets.

E. pallida heads are easily distinguished from E. angustifolia by their white pollen and longer ray florets.

Echinacea pallida, an Echinacea species compatible with E. angustifolia, but not native to our study area, was planted at a restoration at Hegg Lake WMA. One trait of E. pallida may limit its potential to hybridize with E. angustifolia individuals is the synchrony of their flowering timing, or phenology. To study this, we have kept track of the start and end dates of flowering for Echinacea pallida individuals in the Hegg restoration plot since 2011. In 2016, we identified 66 flowering plants with 113 heads. Flowering began on June 18th. Then, around July 7th, we chopped off all the Echinacea pallida heads.

Start year: 2011

Location: Hegg Lake WMA restoration

Overlaps with: Echinacea hybrids (exPt6, exPt7, exPt9),  flowering phenology in remnants

Physical specimens: 113 heads were cut from E. pallida plants circa 7 July 2016 (the last day of recorded phenology). These specimens were likely composted.

Data collected: We collected phenology data using handheld computers.

GPS points shot: We shot points for the 66 flowering E. pallida plants.

Products: In Fall 2013, Aaron and Grace, externs from Carleton College, investigated hybridization potential by analyzing the phenology and seed set of Echinacea pallida and neighboring Echinacea angustifolia that Dayvis collected in summer 2013. They wrote a report of their study.

Previous team members who have worked on this project include: Nicholas Goldsmith (2011), Shona Sanford-Long (2012), Dayvis Blasini (2013), and Cam Shorb(2014)

You can find more information about Echinacea pallida flowering phenology and links to previous flog posts regarding this experiment at the background page for the experiment.

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.

2016 update: Inbreeding experiment–INB2

Reina, Pamela, and Mike with the photosynthesis machine used in Kittelson et al. (2015)

In 2016, we continued the INB2 experiment to investigate the relationship between inbreeding level and fitness in Echinacea angustifolia. Each plant in experiment INB2 originates from one of three cross types, depending on the relatedness of the parents: between maternal half siblings; between plants from the same remnant, but not sharing a maternal or paternal parent; and between individuals from different remnants. We continued to measure fitness and flowering phenology in these plants.

This year, of the original 1,470 plants in INB2, 557 were still alive. Of the plants that were alive this year, 2% were flowering and 75% have never flowered.

Read previous posts about this experiment.

 

Start year: 2006

Location: Experimental plot 1

Overlaps with: Phenology and fitness in P1, Inbreeding experiment–INB1

Physical specimens: We harvested 9 heads from INB2 that will be processed in the lab with other heads harvested from P1.

Data collected: We used handheld computers to collect fitness data on all plants in INB2.

Products: The below papers were published in summer 2015:

Kittelson, P., S. Wagenius, R. Nielsen, S. Qazi, M. Howe, G. Kiefer, and R. G. Shaw. 2015. Leaf functional traits, herbivory, and genetic diversity in Echinacea: Implications for fragmented populations. Ecology 96:1877–1886. PDF

Shaw, R. G., S. Wagenius and C. J. Geyer. 2015. The susceptibility of Echinacea angustifolia to a specialist aphid: eco-evolutionary perspective on genotypic variation and demographic consequences. Journal of Ecology 103:809-818. PDF

You can find more information about the Inbreeding experiment–INB2 and links to previous flog posts regarding this experiment at the background page for the experiment.

2016 update: Inbreeding experiment–INB1

2013-06-19-12-29-42

Reina, Hattie, and Mike with the instrument to measure photosynthesis.

In 2016, we continued the INB1 experiment to investigate the relationship between inbreeding level and fitness in Echinacea angustifolia. Each plant in experiment INB1 originates from one of three cross types, depending on the relatedness of the parents: between maternal half siblings; between plants from the same remnant, but not sharing a maternal or paternal parent; and between individuals from different remnants. We continued to measure fitness and flowering phenology in these plants.

This year, of the original 557 plants in INB1, 191 were still alive. Of the plants that were alive this year, 7% were flowering and 24% have never flowered.

Read previous posts about this experiment.

 

Start year: 2001

Location: Experimental plot 1

Overlaps with: Phenology and fitness in P1

Physical specimens: We harvested 13 heads from INB1 that will be processed in the lab with other heads harvested from P1.

Data collected: We used handheld computers to collect fitness data on all plants in INB1.

Products: The below papers were published in summer 2015:

Kittelson, P., S. Wagenius, R. Nielsen, S. Qazi, M. Howe, G. Kiefer, and R. G. Shaw. 2015. Leaf functional traits, herbivory, and genetic diversity in Echinacea: Implications for fragmented populations. Ecology 96:1877–1886. PDF

Shaw, R. G., S. Wagenius and C. J. Geyer. 2015. The susceptibility of Echinacea angustifolia to a specialist aphid: eco-evolutionary perspective on genotypic variation and demographic consequences. Journal of Ecology 103:809-818. PDF

You can find more information about the Inbreeding experiment–INB1 and links to previous flog posts regarding this experiment at the background page for the experiment.

2016 update: Heritability of fitness–qGen1

The team measuring plants in big batch

Team Echinacea measuring plants in big batch

The qGen1 (quantitative genetics) experiment is designed to quantify the heritability of traits in Echinacea angustifolia. We are especially interested in Darwinian fitness. Could fitness be heritable? During the summer of 2002 we crossed plants from the 1996 & 1997 cohorts of exPt1. We harvested heads, dissected achenes, and germinated seeds over the winter. In the Spring of 2003 we planted the resulting 4468 seedlings (this great number gave rise to this experiment’s nickname “big batch”). In 2016 we assessed survival and fitness measures of the qGen1 plants. 2,187 plants in qGen1 were alive in 2016. Of those, 5% flowered in 2016 and 49% have yet to flower.

Start year: 2003

Location: Experimental plot 1

Overlaps with: qGen2 & qGen3

Physical specimens: We harvested 116 heads from qGen1 in 2016. These heads will be processed in the lab to determine achene count and seed set.

Data collected: We collected fitness measures using handheld computers.

Products: We have an awesome dataset that we will share once the paper is published. Ruth Shaw is working on an analysis of the qGen1 dataset.

You can find more information about Heritability of fitness–qGen1 and links to previous flog posts regarding this experiment at the background page for the experiment.

Project status update: Hesperostipa common garden experiment

The Stipa Project — studying the effects of habitat fragmentation on the ecology and evolution of Stipa, a cool-season grass. In 2009 & 2010 we planted over 4,000 Stipa seeds in exPt 1. We’ve been put to the test trying to find our Stipa plants in a matrix of other grasses, but once they flower they are easy to spot. While we collected seed from Stipa in our common garden in 2014, our 2015 search for flowering Stipa plants was fruitless!

Read more about the Stipa experiment.
Read more about the natural history of Stipa.

Start year: 2009

Location: exPt1

 

Project status update: Heritability of fitness–qGen1

IMG_5695

2015 measuring qGen1: finding EA in a sea of flowering big bluestem!

The qGen1 (quantitative genetics) experiment investigates the heritability of traits in Echinacea angustifolia. During the summer of 2002 we crossed plants from the 1996 & 1997 cohorts of exPt1. We harvested heads, dissected achenes, and germinated seeds over the winter. In the Spring of 2003 we planted the resulting 4468 seedlings (this great number gave rise to this experiment’s nickname “big batch”). In 2015 we assessed survival and fitness measures of the qGen1 plants. Here’s a summary of what we found:

living flowering headCount
2319 409 793

Read more about the qGen1 experiment.

Start year: 2003

Location: exPt1

 

Project status update: Ridley’s next generation rescue

geneticRescueSlide Caroline Ridley established this experiment to compare fitness (recruitment and survival) of seeds originating from individuals with parents from three different backgrounds: 1. both from a large remnant population, 2. both from a small remnant population (not rescued), and 3. one from a large population and one from a small population (genetically rescued). Caroline sowed achenes in an experimental plot at Hegg Lake WMA and marked seedlings with colored toothpicks in May 2009.

We annually assess survival and fitness of these plants. In 2015 we relocated and measured 42 individuals of the 381 seedlings originally found. These plants had 1-3 leaves; the longest leaf was 21 cm. The dense non-native brome grass dominating this plot may be shading out these small plants. It should be interesting to see which individuals are hanging on!

Read more about this experiment.

Start year: 2008

Site: exPt 4 at Hegg Lake WMA

Overlaps with: crossing experiments qGen1, qGen2, qGen3 & recruitment experiment; INB1

Project status update: Heritability of fitness–qGen2 & qGen3

Pollen vials from Landfill sire 403 used in qGen3 crossing 2015

Pollen vials from sire 403 used in qGen3

The goal of the qGen2 and qGen3 experiments is to compare the evolutionary potential of two remnant prairie populations of Echinacea angustifolia by estimating the additive genetic variance of fitness under two mating scenarios: crosses performed within the core sites (core x core) and crosses performed between the core site and nearby sites (core x periphery). Additionally, we will test for differentiation among families; do progeny from sires differ after accounting for maternal (dam) effects?

In June 2015 we assessed survival and measured 1-year-old plants from qGen2. During the summer and fall of 2015 we replicated the qGen2 experiment through a second crossing experiment. We sowed the resulting achenes in exPt 8 as our qGen3 cohort.

Read more about the qgen2 and qgen3 experiments.

IMG_5251

Dam to be crossed with pollen from 2 sires

Start year qGen2: 2013

Start year qGen3: 2015

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