Experimental demonstration of allometric invariance of plant response to density over the course of wheat domestication
Data files
Jun 17, 2025 version files 151.30 KB
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density_database_wheat.xlsx
147.75 KB
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README.md
3.55 KB
Abstract
Crop domestication and breeding have led to phenotypic changes, particularly in plant size. Allometric relationships – the link between trait and size– have been repeatedly described as invariant across taxa, suggesting strong constraints on phenotypic evolution. By analogy, artificial selection during domestication and breeding might have been strongly constrained by plant allometry, but an experimental test is lacking.
We used 39 genotypes representative of the four key stages (wild, first domesticated, landrace, and elite) of the evolutionary history of durum wheat. We grew them in pots as monogenotypic cultures, with increasing density from one to ten individuals. We measured biomass components and functional traits involved in plant competition to assess the response of genotypes to density.
In response to density, wheat genotypes reduced their tillers number and flowered earlier. However, we showed invariant biomass-based responses to density across the different stages. Furthermore, allometric relationships between vegetative biomass and reproductive biomass did not vary across stages, despite phenotypic changes.
Our findings contribute to strengthening empirical knowledge of the phenotypic changes in the aerial compartment over the course of plant domestication. Moreover, they reinforce the interest in using the allometric framework to better understand constraints on crop phenotype and productivity.
Dataset DOI: 10.5061/dryad.stqjq2cfb
Description of the data and file structure
We explore changes in size-density relationships and traits that contributed to increased productivity during domestication and breeding. We used a collection of 39 genotypes representative of the four key stages (wild, first domesticated, landrace and elite) of the evolutionary history of durum wheat. We grew them in pots as monogenotypic culture, with increasing density from one to ten individuals. We measured biomass components and functional traits involved in plant competition (height, tillers number, heading date) to assess the response of genotypes to density.
Files and variables
File: density_database_wheat.xlsx
Description:
Variables
- Genotype_number corresponds to INRAE number genotype.
- Compartment corresponds to the different compartments in the domestication and breeding history of the tetraploid wheat Triticum turgidum. There are four compartment modalities (Wild = dicoccoides; First domesticated = dicoccum; Landraces = durum_landrace*; elite varieties = durum_*elite).
- The block_number corresponds to the three repetitions of the experiment.
- Density corresponds to the density of individuals in the pot (From one to ten plants in the pot).
- Density_ind_m2 corresponds to the estimated density of individuals per m².
- Tiller_number_plot_level corresponds to the number of the total number of tillers per pot on all the plants in the pot.
- Tiller_number_individual_level corresponds to the number of the number of tillers per individual (Total number of tillers per pot divided by the density).
- Plant_vegetative_height_cm corresponds to the height between the soil and the highest leaf in the pot, without stretching in centimeter.
- Heading_date_degree_day corresponds to the date at which spikes were visible for 50% of the plants in a pot, converted in degree day using a 0 °C base temperature.
- Vegetative_biomass_plot_level_g corresponds to vegetative (leaves and stems) biomass in g at the pot level (all the individuals in the pot).
- Vegetative_biomass_individual_level_g corresponds to vegetative biomass in g measured at pot level divided by the density in the pot to obtain individual measurements.
- Reproductive_biomass_plot_level_g corresponds to reproductive (spikes with grains) biomass in g at the pot level (all the individuals in the pot).
- Reproductive_biomass_individual_level_g corresponds to reproductive biomass in g measured at pot level divided by the density in the pot to obtain individual measurements.
- Total_biomass_plot_level_g corresponds to total biomass at the pot level in g which corresponds to the sum of vegetative biomass and reproductive biomass at the pot level.
- Total_biomass_individual_level_g corresponds to total biomass at the individual level in g which corresponds to total biomass at the pot level divided by the density of individuals in the pot.
- Ratio_reproductive_biomass_total_biomass corresponds to the reproductive effort as the ratio of spike biomass divided by the sum of vegetative biomass and spike biomass measured at pot level.
- “NA” corresponds to missing values in the dataset.
Code/software
All statistical analyses were performed with R version 4.4.0 (R Core Team, 2024). We used the package ggplot2, cowplot, performance, lme4, lsmeans, emmeans and smatr.