Categories

Authors

2018 update: Pollen addition and exclusion

Michael adds pollen to one of the “addition” plants using a toothpick and a vial of collected pollen.

Does receiving the maximum amount of pollination vs. no pollen at all affect a plant’s longevity or likelihood of flowering in subsequent years? Since 2012, we have been either adding or excluding pollen from the same plants’ heads to test what role pollen plays in survival and flowering. Unlike the previous two years, many heads in this experiment flowered this year, and analyzing them will likely reveal interesting results.

This summer, 14 of the 26 plants remaining in the pollen addition and exclusion experiment flowered, for a total of 25 heads. This is the most heads the pollen addition and exclusion project has had since 2013. We continued experimental treatments on these flowering plants and recorded the survival and flowering status of all plants in the experiment. Of the original 38 plants in this experiment, 12 of the exclusion plants and 14 of the pollen addition plants are still alive.

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. The increase in flowering rates this year will allow us to move forward with analyzing this data set, to potentially answer this 7-year question

Start year: 2012

Location: Experimental plot 1

Physical specimens: We harvested 25 flowering heads from this experiment that will be pulled from the normal ACE processing and pushed through faster. This is so we can more quickly determine achene count and proportion of full achenes.

Data collected: Plants survival and flowering data was recorded as part of our annual surveys in P1 and can be found with the rest of the P1 data. Data on when heads had pollen added can be found in CGData/115_pollenLimitation, particularly dailyPollenAddition for the year 2018.

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.

A Farewell to Aphids

This morning the much-diminished Team Echinacea (Stuart, Kristen, Lea, Michael, and I) gathered at the Hjelm house to start the day. Lea went to Staffenson Prairie Preserve to measure the flowering phenology of Liatris and Solidago plants. Michael and Kristen began to prepare experimental plot 8 for management in the coming year. The team will treat rogue Ashe trees and collect and broadcast the seeds of several prairie plant species in this plot. This is part of an ongoing effort to ensure that the plant community within the plot is consistent throughout.

Meanwhile, I assessed the leaf damage and senescence of plants in the aphid addition/exclusion experiment in p1. This was the final component of the fieldwork involved in this experiment for the season, and the last step in my independent project before I begin statistical analysis. The next step is to gauge fitness differences between plants in the aphid addition and exclusion treatments by constructing an aster model. While it was exciting to finish this aspect of the project, I will miss spending time with my Aphis echinaceae friends.

Over lunch the team prepared for inclement weather by sharing our experiences of intense weather events. After that, Kristen presented an update on her master’s project. She shared some intriguing preliminary results about the nesting preferences of native ground-nesting bees. We are all looking forward to the results of her study! Due to the rainy weather, the team was ready to call it a day after Kristen’s presentation. We held a short meeting to plan next week’s schedule and then headed home for the weekend.

Manuscript Submitted (Finally!)

Hi Flog!

I just wanted to give you all a quick update on the heritability of flowering time project I have been working on (for a long time)! We collected data on the phenology of the plants at experimental plot 2 during the summers of 2015 and 2016 and the phenotypes of those individuals to the phenotypes of their parents in 2005. Jennifer Ison began this project as a part of her dissertation in 2006 and I was lucky enough to pick it up when the individuals in experimental plot 2 really began to flower.

Since we collected data in ’15/’16 we have been working on analyses to determine the amount of variation in flowering time that is heritable. We found that there is substantial heritability for both onset of flowering and duration of flowering. Both of these traits are critical in describing the synchrony of an individual compared to the population and for determining the number of mating opportunities an individual will have in a season.

Today we submitted the manuscript that describes these results to Evolution. Drafting this manuscript has been an excellent learning opportunity for me and I have been lucky to work with some amazing scientists and writers. Thank you to my co-authors: Jennifer Ison, Stuart Wagenius, Frank Shaw, and Ruth Shaw.

2017 update: Echinacea pallida flowering phenology

Anna and Will decapitate a plant. It’s Echinacea pallida which is not native to Minnesota.

Echinacea pallida is an Echinacea species that is not native to Minnesota. In July 2017, we identified 100 flowering E. pallida plants with 222 heads that were planted in a restoration at Hegg Lake WMA. Every year for the past several years, we have visited the E. pallida plants, taken phenology data, and chopped off their heads. On July 7, 2017 when we collected the data, the maximum male row was 19, meaning flowering started about 19 days earlier–June 18, 2017. E. angustifolia in the remnants started flowering on June 24, about a week later. 17 of the 222 E. pallida heads were still buds on 7 July, so these plants would have continued flowering for awhile.

We went back to check if we missed any heads on 31 August and found two. They were done flowering, but hadn’t dropped seeds.

Start year: 2011

Location: Hegg Lake WMA restoration

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

Physical specimens: 222 heads were cut from E. pallida plants and likely decomposed. We brought two heads back with us to Chicago.

Data collected: A csv in ~Dropbox/remData/105_assessPhenology/phenology2017 with tag, row number the male florets were at on July 7, 2017 for each head, and initials of the data collector.

GPS points shot: We shot points for the 100 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.

2017 update: Flowering phenology in experimental plots

This year, the number of flowering plants in our main experimental plot (exPt1) dropped in half compared to last year. This might be due to the lack of a burn in the prior fall or spring. Plot 2 (exPt2) had about the same number of heads in ’16 & ’17.

In exPt1, we kept track of approximately 72 heads. The peak date was July 19th. The first head started flowering on July 2nd and the last head finished up on August 21st. In contrast, we kept track of 1076 heads in exPt2, about 140 more than last year! The peak date for these Echinacea was a bit earlier, July 13th. exPt2 heads also started and ended earlier (June 22 – August 19).

We harvested the heads at the end of the field season and brought them back to the lab, where we will count fruits (achenes) and assess seed set.

Flowering schedules for 2017 in exPt1 and exPt2. Black dots indicate the number of flowering heads on each date. Gray horizontal line segments represent the duration of each head’s flowering and are ordered by start date. The solid vertical line indicates peak flowering, while the dashed lines indicate the dates when 25% and 75% of heads had begun flowering, respectively. Note the difference in y-axes between the two plots. Click to enlarge!

Start year: 2005

Location: Experimental Plots 1 and 2

Overlaps with: Heritability of flowering time, common garden experiment, phenology in the remnants

Physical specimens: Harvested heads from both experimental plots are in the lab at CBG. The ACE protocol for these heads will begin soon.

Data collected: We visit all plants with flowering heads every 2-3 days starting before they flower until they are done flowering to record start and end dates of flowering for all heads. We managed phenology data in R and added it to our long-term dataset. The figures above were generated using package mateable in R. If you want to make figures like this one, download package mateable from CRAN!

You can find more information about phenology in experimental plots and links to previous flog posts regarding this experiment at the background page for the experiment.

 

 

2017 update: Ridley’s next generation rescue

geneticRescueSlideIn 2017 Stuart and Lea relocated and measured 19 individuals of the 381 seedlings originally found. These plants had 1-4 leaves; the longest leaf was 32 cm. It should be interesting to see which individuals are hanging on!

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.

Start year: 2008

Site: exPt 4 at Hegg Lake WMA

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

You can find more information about Ridley’s next generation rescue and links to previous flog posts regarding this experiment at the background page for this experiment.

2017 Update: Echinacea hybrids — exPt 9

This summer, we measured open-pollinated hybrid Echinacea plants in experimental plot 9 at Hegg Lake. The table below shows the number of plants found alive during each search since the experiment started in 2014. Of the surviving plants in 2017, 90% had fewer than 3 leaves, the mean length of the longest basal leaf was 25 cm, and only six plants had more than one basal rosette. This year we searched for plants once then rechecked every position where we didn’t find a plant during our first search. No plants flowered this year.

Year / Event Number Alive % Original remaining % Of previous year
Planting (2014) 746 100
2014 638 85.5 85.5
2015 521 69.8 81.7
2016 493 66.1 94.6
2017 401 53.8 81.3

This experiment comparing the fitness of Echinacea hybrids with pure-bred E. angustifolia and E. pallida will give insight into the possible consequences of non-native E. pallida being planted in restorations in Minnesota, where E. angustifolia is the only native Echinacea.

Measuring at Hegg Lake

Start year: 2014

Location: Hegg Lake Wildlife Management Area — experimental plot 9

Overlapping experiments: Echinacea hybrids — experimental plot 6Echinacea hybrids — experimental plot 7

Data collected: Rosette number, length of all leaves, herbivory for each plant collected electronically and exported to CGData. Recheck information for plants not found was also collected electronically and stored in CGData.

You can find out more information about experimental plot 9 and flog posts mentioning the experiment on the background page for the experiment.

2017 Update: Echinacea hybrids — exPt 7

This summer, we measured hybrid Echinacea plants in experimental plot 7 at Hegg Lake. 159 of the original 294 planted seedlings (54%) were found this year. We searched 243 of the 294 positions where plants were originally planted (the other 51 positions were not searched because plants have not been found for at least three years in a row). The table below shows the fate of plants in 2017 summarized by cross-type — the first name in the cross type is the maternal species, and the second name is the paternal species (e.g., ‘ang x pal’ is angustifolia mother and pallida father).

Status 2017 ang x ang ang x pal pal x ang pal x pal
not found 53 10 33 35
found 21 18 52 72

Flowering Echinacea angustifolia.

Start year: Crossing in 2012, Planting in 2013

Location: Hegg Lake Wildlife Management Area – Experimental Plot 7

Overlaps with: Echinacea hybrids: ex Pt 6; Echinacea hybrids: ex Pt 9

Data collected: Rosette number, length of all leaves, herbivory for each plant collected electronically and exported to CGData. Recheck information for plants not found was also collected electronically and stored in CGData.

Products: Taylor Harris’s 2015 poster demonstrating fitness benefits of pallida parenthood.

You can find more information and links to previous flog entries involving experimental plot 7 on the background page for the experiment.

2017 Update: Echinacea hybrids– exPt 6

In 2017,  we searched for 56 of the original 66 Echinacea hybrid plants. We found 28 Echinacea hybrids, and 2 of the Echinacea hybrids we found just had dead leaves from this year.  This means that 42% of the original cohort is still alive, with the survival rate this winter of 78%. Of the surviving plants, the highest leaf count was 5 leaves, the longest basal leaf was 35cm, and only one plant had more than one basal rosette.

Most plants we measured in exPt6 looked like this.

This plot was originally developed for Josh Drizin’s experiment with exotic grasses, but 66 hybrids of Echinacea angustifolia and Echinacea pallida were also planted in 2012. In 2011, Gretel and Nicholas Goldsmith performed reciprocal crosses between 5 non-native pallida plants found at Hegg Lake and 31 angustifolia plants in P1. These plants have been revisited each summer since then.

Year started: Crossing in 2011, planting in 2012

Location: Experimental Plot 6, on Tower Road

Overlaps with: Echinacea hybrids — ex Pt 7, Echinacea hybrids — ex Pt 9

Data collected: Status, rosette count, longest leaf measurement, and number of leaves for each plant. Exported to CGData.

Products: Nicholas Goldsmith wrote a summary of the crosses he conducted in 2011.

You can find more information about experimental plot 6 and previous flog posts about it on the background page for the experiment.

2017 update: Heritability of fitness–qGen2 & qGen3

Alex and Tracie search for juvenile Echinacea plants in experiments qGen2 & qGen3.

In 2017, we found 1006 three-year-old plants out of the 2526 original seedlings found in 2014 (we found 1724 plants in 2016) in the qGen2 cohort. In the qGen3 cohort we found 248 of the 644 seedlings.

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?

Comparing germination and first year survival between the qGen2 & qGen3 cohorts:

exp approxFullAcheneCt totalAcheneCt seedlingCt germination firstYrSurvival
qGen2 6300 26144 2581 41% 84%
qGen3 6200 19777 644 10% 38%


Start year qGen3:
 2015

Start year qGen2: 2013

Location: The sires (pollen donors) are in the remnants Landfill and Staffanson. The dams (seed plants) are in exPt 1 and they originate from remnants. Specifically, the grand-dams (seed plants of dams) are from remnants Landfill (core) & around Landfill (peripheral) and remnants Staffanson (core) & railroad crossing sites (peripheral). All progeny are in exPt 8.

Overlaps with: Heritability of fitness–qGen1

Data collected: We used handheld computers to collect data on 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.