A reaction norm for flowering time plasticity reveals physiological footprints of maize adaptation

Understanding how plant phenotypes are shaped by their environments is crucial for addressing questions about crop adaptation to new environments. This study focused on analyzing the genetic variability underlying genotype-by-environment interactions and adaptation for flowering time in maize. We developed the use of a physiological reaction norm for flowering time plasticity (PRN-FTP) modeled from multi-environment trial networks, with genotype-specific parameters putatively linked to different regulatory modules for flowering time. We show how genotype-specific differences in developmental responses to temperature fluctuations condition differences in photoperiod perceived among genotypes. This occurs not only across but also within common environments, as the perception of photoperiod is altered by variation in rates of development and durations for becoming sensitized to photoperiod. Using a new metric for envirotyping sensed photoperiods for maize, it was found that, at high latitu..., Datasets (“D”) from multiple projects and experiments were assembled to: (D1) select a temperature response function for thermal time estimation; (D2) estimate variation in the thermal time duration between crop emergence and tassel initiation (Ttem-ti) in order to develop an index for sensed photoperiod (DLs); (D3) envirotype DLs in maize fields across the Northern Hemisphere; (D4) demonstrate methods for modeling a physiological reaction norm for flowering time plasticity (PRN-FTP); and (D5) compare the trait space of parameters estimated from the PRN-FTP in a diversity panel constituting separate breeding pools of maize. The current study focused on days to anthesis (male flowering) as the final characteristic.
(D1) Three temperature response functions (Methods S1, Eq. S1-S3) for measuring thermal time were compared using MET data with 24 hybrids tested in 25 to 26 field environments, spanning latitudes from 30.5371° N to 44.2089° N (File S1; data sourced from the Genomes-To-Fields I..., , # Data from: A reaction norm for flowering time plasticity reveals physiological footprints of maize adaptation

[https://doi.org/10.5061/dryad.x95x69pth](https://doi.org/10.5061/dryad.x95x69pth)

## Description of the data and file structures

### File\_S1. Estimates of thermal time from planting to male flowering (anthesis) for Genomes-To-Fields data used to compare temperature response functions.

Dataset D1: Contains metadata and best linear unbiased estimates (BLUEs) for days to anthesis (DTA) of 24 hybrids in 25-26 field environments. Field metadata and BLUEs for DTA were assembled from McFarland et al (2020) and Rogers et al. (2021) (see Main text). Three temperature response functions (Eq. S1-S3, Methods S1 of Main text) were used to estimate thermal times.

File_S1.txt (tab delimited); description of columns
env: environment code (year x location)
year: year of planting
lat: latitude of field environment
lon: longitude of field environment
hybrid: hybrid name
date_planted: plan...