*4.3. Growth and Development*

Projected leaf area (PLA; i.e., total visible leaf area) was used as a proxy for growth, while the number of visible leaves was used as a proxy for development. For both variables, images of Fm, obtained with the imaging PAM, were used (Figure S4B). ImageJ (https://imagej.nih.gov/ij/) was used to calculate PLA from the number of pixels per plant; pot diameter was used to scale pixel number to actual plant size. Average leaf size was obtained by dividing PLA by the number of visible leaves.

#### *4.4. Clustering of Accessions by Phenotypic Di*ff*erences*

Accessions were clustered into different categories depending on log−2-transformed values of the response ratio (ΔP), which was calculated for each parameter (P) as ΔP = PFL/PU, where PU and PFL are the average values of the parameter for each accession. Cluster 3.0 (http://www.falw.vu/~{}huik/ cluster.htm) with Euclidean distance as similarity metric and average linkage was used. Based on this result, categories were manually adjusted to fit the specified criteria.
