ABSTRACT
Many plant biophysical responses to the environment are finely regulated by gene expression and the complexity of this interaction limits the predictive capacity of existing approaches. This chapter investigates the use of chlorophyll a fluorescence (ChlF) in phenotyping. It reviews the basics of the Pulse Amplitude Method and compares low and high-throughput instruments that utilize this ChlF technique. The chapter presents several applications of the method to illustrate the sensitivity of ChlF in capturing genotypic difference, species variability, and stress response. It aims to showcase ChlF as an integrative phenomics tool. The chapter also presents physiological data from several species and genotypes under different environmental conditions to highlight the vast applicability of ChlF as a robust tool in plant phenotyping. It synthesizes data collected on the herbaceous crop Brassica rapa, the gymnosperm Pinus ponderosa, and two angiosperms, Populus tremuloides, a tree, and Artemisia tridentata, a shrub.
