DOI: 10.5061/dryad.p5hqbzkr1
title: Effects of primary seed dormancy on life-time fitness of Arabidopsis thaliana in the field

description: Background and Aims Seed dormancy determines the environmental niche of
 plants in seasonal environments, and has consequences for plant
 performance that potentially go far beyond the seed and seedling stages.
 In this study, we examined the cascading effects of seed dormancy on the
 expression of subsequent life-history traits and fitness in the annual
 herb Arabidopsis thaliana.  Methods We planted seeds of
 &gt;200 recombinant inbred lines (RIL) derived from a cross between
 two locally adapted populations (Italy and Sweden), and both parental
 genotypes at the native site of the Swedish population in three
 consecutive years. We quantified the relationship between primary seed
 dormancy and the expression of subsequent life-history traits and fitness
 in the RIL population with path analysis. To examine effects of
 differences in dormancy on relative fitness of the two parental genotypes,
 we planted dormant seeds during the seed dispersal period and non-dormant
 seeds during the germination period of the local population. Key Results
 In the RIL population, strong primary dormancy was associated with high
 seedling survival, but with low adult survival and fecundity, and the path
 analysis indicated that this could be explained by effects on germination
 timing, rosette size, and flowering start. The relationship between
 primary seed dormancy and germination proportion varied among years, and
 this was associated with differences in seasonal changes in soil moisture.
 The planting of dormant and nondormant seeds indicated that the lower
 primary dormancy of the local Swedish genotype contributed to its higher
 germination proportion in two years, and to its higher fecundity in one
 year.  Conclusions Our results show that seed dormancy affects
 trait expression and fitness components across the life cycle, and suggest
 that among-year variation in the incidence of drought during the
 germination period should be considered when predicting the consequences
 of climatic change for population growth and evolution.
description: The data set includes data used in the analyses presented in the
 paper Postma, F. M., and J. Ågren. 2022. Effects of primary seed dormancy
 on life-time fitness of <em>Arabidopsis thaliana</em> in the
 field. Annals of Botany, <em>in press</em>. Methods are
 described in detail in this paper. The data are found
 in four excel files. A brief summary of methods used to obtain the data in
 each file are given below.
 PostmaAgren_ParentalGenotypes.xlsx In each of
 3 years (2012, 2013, and 2014), seeds of an Italian and a Swedish genotype
 were planted at Rödåsen, north-central Sweden (the site of origin of the
 Swedish genotype) either as primary dormant seeds at the time of seed
 dispersal in the local natural population, or as non-dormant seeds at the
 time of seed germination in the local population. The primary dormant
 seeds had been produced at the site and were collected at seed maturation
 14-19 days prior to sowing. Each genotype was planted in 80 replicates
 (primary dormant seeds in each of the three years, non-dormant seeds in
 the 2012 experiment), 60 replicates (non-dormant seeds in the 2013
 experiment), or 30 replicates (non-dormant seeds in the 2014 experiment).
 Each replicate consisted of 40 seeds sown in one cell of a plug tray,
 except for non-dormant seeds in the 2014 experiment of which 20 seeds were
 planted in each cell. The excel file includes data on sowing day (day when
 seeds were planted), germination proportion, seedling and adult survival,
 fecundity (number of fruits produced by fruit-producing plants), fitness
 (fruit production per planted viable seed), germination time, rosette size
 and flowering start.
 <br>PostmaAgren_RILs.xlsx In each of 3
 years, primary dormant seeds of 219 (2012), 220 (2013), and 204 (2014)
 recombinant inbred lines derived from a cross between the Italian and the
 Swedish genotype were planted at Rödåsen, north-central Sweden (the site
 of origin of the Swedish parental genotype) during the natural seed
 dispersal period in early summer. The seeds had been produced at the site
 and were collected 14-19 days prior to sowing. Each line was sown in up to
 10 replicates in the 2012 and 2013 experiments, with each replicate
 consisting of 40 seeds sown in one cell of a plug tray. In the 2014
 experiment, we planted 5 replicates per recombinant inbred line, with 40
 seeds per replicate for 180 RILs and between 20-35 seeds per replicate for
 40 RILs. Low seed production at the experimental site in 2014 made it
 necessary to reduce the number of replicates (number of plugs sown), and
 the number of seeds sown per plug of some lines. The excel file includes
 the following data: dormancy score of seeds produced at the field site by
 the recombinant inbred lines (obtained in a previous experiment), and mean
 phenotypes of each recombinant inbred line in the experiments established
 in 2012, 2013, and 2014. Phenotypes are mean germination proportion,
 seedling and adult survival, fecundity (number of fruits produced by
 fruit-producing plants), germination time, rosette size and flowering
 start (2013 and 2014 experiments only).
 PostmaAgren_NaturalPopulation.xlsx Number of seedlings with
 cotyledons only and number of seedlings with true leaves were regularly
 monitored in 25 squares of 10 x 10 cm in the natural population at the
 site of the experiment (Rödåsen, north-central Sweden) in 2012, 2013, and
 2014. The excel file includes data on number of seedlings with only
 cotyledons, number of seedlings with true leaves, and total number of
 seedlings in the plots at each census.
 PostmaAgren_SoilConditions.xlsx Soil
 temperature and water potential were recorded hourly by sensors placed ca.
 1 cm below the soil surface at the experimental site at Rödåsen,
 north-central Sweden. The excel file includes data on minimum, mean, and
 maximum daily soil temperature, and mean daily water potential (kPa) in
 2012, 2013, and 2014.
description: Please, see ReadMe file.