Classifying cold stress responses of inbred maize seedlings using RGB imaging

Abstract

16Increasing the tolerance of maize seedlings to low temperature episodes could mitigate the 17 effects of increasing climate variability on yield. To aid progress toward this goal, we established 18 a growth chamber-based system for subjecting seedlings of 40 maize inbred genotypes to a 19 defined, temporary cold stress while collecting digital profile images over a 9-day time course. 20Image analysis performed with PlantCV software quantified shoot height, shoot area, 14 other 21 morphological traits, and necrosis identified by color analysis. Hierarchical clustering of changes 22in growth rates of morphological traits and quantification of leaf necrosis over two time intervals 23 resulted in three clusters of genotypes, which are characterized by unique responses to cold 24 stress. For any given genotype, the set of traits with similar growth rates is unique. However, the 25 patterns among traits are different between genotypes. Cold sensitivity was not correlated with 26 the latitude where the inbred varieties were released suggesting potential further improvement 27 for this trait. This work will serve as the basis for future experiments investigating the genetic 28 basis of recovery to cold stress in maize seedlings. 29

Utilizing spatial variability from hyperspectral imaging to assess variation in maize seedlings

“…The first experiment (E1) consisted of three replicates of five genotypes of maize seedlings under four treatment groups (control, cold, salt, and heat) imaged at a single time point. The chosen genotypes were previously demonstrated to differ in morphological responses to cold stress (Enders et al., 2019). The second experiment (E2) consists of two genotypes under four treatment groups (control and three severities of salt stress) imaged at three timepoints (immediately before the stress, 2 d following the stress treatment, and 4 d after following the stress treatment).…”

“…Red–green–blue side‐view images of each set of plants were collected immediately following hyperspectral data collection using the procedures specified in Enders et al. (2019).…”

“…Sensors that measure different ranges of the electromagnetic spectrum have been applied in agriculture. Red–green–blue (RGB) imaging has been widely used to extract morphological traits linked to plant productivity such as plant height across different crop species in field and indoor settings (Enders et al., 2019; Feng et al., 2018; Varela et al., 2017; Watanebe et al., 2017). Thermal imaging and near infrared combined with visible imaging have been used to extract information of drought stress across grasses and legume crops (Benavente et al., 2013; Biju et al., 2018; Jin et al., 2017; Martynenko et al., 2016; Zhang et al., 2012).…”

A Review of Imaging and Sensing Technologies for Field Phenotyping

“…Several studies have shown the applicability of RGB to obtain relevant information about plants status, e.g. to evaluate growth and flowering dynamics (Ge, Bai, Stoerger, Schnable, 2016;Guo, Fukatsu, Ninomiya, 2015), growth of plant shoots (Golzarian et al, 2011), and yield traits (Fernandez-Gallego et al, 2019), to count seedlings in a field (Liuet al, 2016), predict plant density (Ranđelović et al, 2020), plant stress (Enders et al, 2019;Briglia et al, 2019;Li et al, 2018) and more. Description of the typical devices and software used in plant phenotyping measurement are listed in Table 1.…”

Integrated morpho‐biochemical and transcriptome analyses reveal multidimensional response of upland cotton (Gossypium hirsutumL.) to low temperature stress during seedling establishment

“…Low temperature is a key environmental factor limiting the geographical distribution and productivity of crops that are adapted to tropical/subtropical climates (DeRidder & Crafts-Brandner, 2008;Yadav, 2010). Depending on the onset and duration of cold stress, the severity of its impact to plant growth and development varies (Enders et al, 2019). Some of the earliest responses of a plant to cold exposure include modifications in cell membrane flexibility, changes in ionic fluxes, and reduced cytoplasmic streaming, accompanied by the excessive generation of highly reactive oxygen species (ROS).…”