DOI: 10.5061/dryad.18931zcsh
title: Data from: The invasive plant Solidago canadensis exhibits partial local adaptation to low salinity at germination but not at later life‐history stages

description: Premise: Evolutionary adaptation may enable plants to inhabit a broad
 range of environments. However, germination and early life‐history stages
 have seldom been considered in estimates of evolutionary adaptation.
 Moreover, whether soil microbial communities can influence evolutionary
 adaptation in plants remains little explored. Methods: We used
 reciprocal transplant experiments to investigate whether two populations
 of an invasive plant Solidago canadensis that occur in contrasting
 habitats of low versus high salinity expressed adaptation to the
 respective salinity levels. We germinated S. canadensis seeds collected
 from low‐and high‐salinity habitats under low‐ and high‐salt treatments.
 We also raised S. canadensis seedlings from the two salinity habitats
 under low‐ and high‐salt treatments and in the presence versus absence of
 microbial communities from the two habitats. Results: Genotypes
 from a low‐salinity habitat had higher germination rates under low‐salt
 treatment than genotypes from a high‐salinity habitat. However, both
 genotypes had similar germination rates under a high‐salt treatment. The
 two genotypes also had similar seedling survival and biomass responses to
 low‐ and high‐salt treatments. Nevertheless, seedling biomass was
 significantly higher under low salt treatment. Soil microbial communities
 did not influence biomass of S. canadensis under the two salt treatments.
 Conclusions: The results on germination rates suggest partial
 local adaptation to low salinity. However, there was no evidence of local
 adaptation to salinity at the seedling survival and growth stages. The
 finding that germination and seedling biomass responded to different salt
 treatments suggests that the two traits are important for salt tolerance.
description: <strong><em>Seed and soil sampling </em></strong> In November 2016, we collected seeds and rhizospheric soil of <em>S. canadensis</em> in two contrasting habitats with low (inside a dam) and high (outside a dam) NaCl concentration near Haixing village in Zhejiang province (<strong>Table 1</strong>). The two habitats were separated by <em>c.</em>1000 m. Although high soil salinity may be due to high concentrations of Na<sup>+</sup>, K<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, Cl<sup>-</sup>, SO4<sup>2</sup>-, CO3<sup>2-</sup> or HCO<sup>3-</sup> ions, high concentrations of NaCl is considered to be a major cause of soil salinity (Yadav et al., 2011). Therefore, we used NaCl content of the soil as an indicator of soil salinity. Accordingly, we considered soil inside the dam that had a NaCl concentration of 0.2% to represent low salinity while soil outside the dam that had a NaCl concentration of 0.4% to represent high salinity. We measured soil salinity in the two habitats by determining the total soluble salts by evaporation of a soil water extract (Bao, 1999). In each habitat, we collected seeds and rhizospheric soil from 10 randomly sampled <em>S. canadensis</em> individuals (i.e. 10 maternal families per habitat) that were separated by more than 10 meters to avoid sampling the same genet. We stored seeds from each maternal family separately, but pooled and homogenized rhizospheric soils across individuals within each habitat. We stored seeds at 4℃ and soils at -20℃ until use. <strong><em>Experiment 1: Testing whether S. canadensis had evolved adaptation to soil salinity at the germination stage</em></strong> To test whether <em>S. canadensis</em> was adapted to low and high salinity levels at the germination stage of development, we performed germination tests by sowing <em>S. canadensis</em> seeds from low-saline and high-saline habitats in media with low and high salt contents. Four treatment combinations resulted from a fully factorial crossing of <em>S. canadensis</em> seed origin with salt treatment: two levels of <em>S. canadensis</em> seed source (low-salinity vs. high-salinity) x two levels of salt concentration (0.2% vs. 0.4% NaCl). Each treatment combination was replicated six times (i.e. six Petri dishes per <em>S. canadensis</em> seed source per salt treatment). We placed 10 <em>S. canadensis</em> seeds per Petri dish (each maternal family was represented by one seed). The Petri dishes (11 cm in diameter) were lined with a sterilized filter paper. In each Petri dish, we applied 3 ml of the corresponding salt solutions daily for 12 days. To attain salt solutions corresponding to 0.2% and 0.4% NaCl, we dissolved 0.2g and 0.4g of NaCl in 100 ml of sterilized deionized water, respectively. In a pilot experiment, we found that <em>S. canadensis</em> seeds germinated within 10 days. As such, in this experiment, we recorded the proportion of seeds that germinated on the 12<sup>th</sup> day following sowing. We conducted the experiment in a walk-in climate chamber (25°C/20°C day/night and 12h/12h light/dark cycles) at Taizhou University, China in July 2017. The Petri dishes were arranged randomly within the climate chamber. For each maternal family, we determined germination rate on the 12<sup>th</sup> day as follows: (total number of seeds that germinated / total number of seeds that had been placed in a Petri dish) × 100. In each Petri dish, we had marked the individual positions of each family and hence it was possible to track germination per family. <strong><em>Experiment 2: Testing the potential effect of soil microbial community on adaptation of S. canadensis to salinity </em></strong> To test whether soil microbial community influenced adaptation of <em>S. canadensis</em> to salinity, we grew <em>S. canadensis</em> seedlings raised from seeds that had been collected from low-salinity and high-salinity habitats in a substrate with low (0.2% NaCl) and high (0.4% NaCl) salt concentrations and in the presence versus absence of soil microbial communities from low-salinity and high-salinity habitats. We grew the seedlings in small plastic pots (diameter =5.2 cm; height =9 cm; four holes at the bottom) filled with a sterilized commercial potting substrate (a mix of peat, sand and vermiculite in the ratio 6:3:1, v/v/v) that had been inoculated with soil microbes from low-salinity and high-salinity habitats and treated with 0.2% NaCl and 0.4% NaCl. We transplanted four 20-day old <em>S. canadensis</em> seedlings (<em>c.</em> 2-cm tall) into each pot. A total of ten seedlings, which were distributed in the different treatment combinations died within the first seven days of transplant. We considered the seedlings to have died of transplant shock rather than salt toxicity because transplant shock had previously been reported for <em>S. canadensis</em> in a non-saline soil (Yuan et al., 2013). Therefore, we replaced a dead seedling with another one from the same maternal family and age in the seedling stock. We inoculated each pot with microbial communities by adding 5% (volume/ volume) (see Lau and Lennon, 2011) of the rhizospehric soil collected as described above. Prior to inoculation, the rhizospheric soil was taken out of storage at -20℃ and incubated on a laboratory bench at 20<sup>o</sup>C for 48 hours (see Li et al., 2017). We sterilized the potting substrate by autoclaving at 121°C for two hours. The fully factorial experimental design resulted in a total of eight treatment combinations: two levels of <em>S. canadensis</em> seed source (low - salinity vs. high - salinity) x two levels of salt concentration (0.2% vs. 0.4% NaCl) x two sources of soil microbial community origin (low-salinity vs. high-salinity). Each treatment combination was replicated four times (i.e. four pots per treatment combination). The pots were arranged randomly within a climate chamber with the same growth conditions as the germination experiment above. The plants were watered regularly as needed. We monitored plant responses to treatment conditions for three months, spanning August - October 2017. After three months of growth, we harvested all the experimental plants and washed their roots to remove soil particles and oven-dried them at 105°C for one hour and then at 80°C to a constant weight. We then determined the total biomass (root and shoot together) of individual <em>S. canadensis</em> plants to an accuracy of 0.01 g.
description: # The invasive plant Solidago canadensis exhibits partial local adaptation
 to low salinity at germination but not at later life‐history stages This
 README file was generated on 2024-02-20 by Junmin Li. Date of data
 collection: Data were collected on 2017 ### Links to publications that
 cite or use the data Jin HF, Yuan YG, Gao FL, Oduor AMO, Li JM. The
 invasive plant Solidago canadensis exhibits partial local adaptation to
 low salinity at germination but not at later life-history stages. American
 Journal of Botany, 2020, 107(4): 1C8 #### File description Data is in a
 excel document with three sheets. #### Description of the data 1. SO &
 SC sheet Salt concentration: 1-high salt concentration, 2-low salt
 concentration Seeds origin: 1- seeds collected from low salt concentration
 location; 2- seeds collected from high salt concentration location
 Germination rate (%): The total number of seeds that germinated on the
 12th day/ total number of seeds that had been placed in a petri dish on
 the 12th day) 100%. 2. MO & SO & SC TB sheet Microbial communities
 origin: 1-microbal community from soil collected from low salt
 concentration location; 2-microbal community from soil collected from high
 salt concentration location Seeds origin: 1- seeds collected from low salt
 concentration location; 2- seeds collected from high salt concentration
 location Salt concentration: 1-high salt concentration 2-low salt
 concentration Total biomass (g): The dry weith of whole plant 3. SO &
 MO & SC SS sheet Seeds origin: 1- seeds collected from low salt
 concentration location; 2- seeds collected from high salt concentration
 location Microbial community origin: 1-microbal community from soil
 collected from low salt concentration location; 2-microbal community from
 soil collected from high salt concentration location Salt concentration:
 1-high salt concentration 2-low salt concentration Seedling survival rate:
 The proportions of seedlings that survived at the pot level after three
 months growth