Toward predicting photosynthetic efficiency and biomass gain in crop genotypes over a field season

Abstract

Photosynthesis acclimates quickly to the fluctuating environment in order to optimize the absorption of sunlight energy, specifically the photosynthetic photon fluence rate (PPFR), to fuel plant growth. The conversion efficiency of intercepted PPFR to photochemical energy (ɛe) and to biomass (ɛc) are critical parameters to describe plant productivity over time. However, they mask the link of instantaneous photochemical energy uptake under specific conditions, i.e., the operating efficiency of photosystem II (Fq’/Fm’), and biomass accumulation. Therefore, the identification of energy-, and thus resource-efficient genotypes under changing environmental conditions is impeded. We long-term monitored Fq’/Fm’ at the canopy level for twenty-one soybean (Glycine max (L.) Merr.) and maize (Zea mays) genotypes under greenhouse and field conditions using automated chlorophyll fluorescence and spectral scans. Fq’/Fm’ derived under incident sunlight during the entire growing season was modeled based on genotypic interactions with different environmental variables. This allowed us to cumulate the photochemical energy uptake and thus estimate ɛe non-invasively. ɛe ranged from 48 to 62%, depending on the genotype, and up to 9% of photochemical energy was transduced into biomass in the most efficient C4 maize genotype. Most strikingly, ɛe correlated with shoot biomass in seven independent experiments under varying conditions with up to r = 0.68. Thus, we estimated biomass production by integrating photosynthetic response to environmental stresses over the growing season and identified energy-efficient genotypes. This has great potential to improve crop growth models and to estimate the productivity of breeding lines or whole ecosystems at any time point using autonomous measuring systems.

Harnessing the Role of Foliar Applied Salicylic Acid in Decreasing Chlorophyll Content to Reassess Photosystem II Photoprotection in Crop Plants

“…Foliar application of 1 mM SA on tomato leaves decreased the excitation pressure at PSII (1 − qp), compared to the untreated one (Figure 2d), also decreasing the excess excitation energy (EXC) (Figure 3a). The conversion efficiency of absorbed light energy to photochemical energy is critical in describing plant productivity over time [33].…”

“…The light energy absorbed by PSII antennae can be either utilized via photochemistry or competitively dissipated via various thermal processes [29][30][31][32]. The conversion efficiency of absorbed light energy to photochemical energy is critical in describing plant productivity over time [33]. The light reactions of photosynthesis involve a set of redox reactions that are the source of reducing power and energy for producing organic compounds [34].…”

Mechanistic Insights on Salicylic Acid Mediated Enhancement of Photosystem II Function in Oregano Seedlings Subjected to Moderate Drought Stress

“…Thus, SA application was suggested to improve PSII function by reducing photoinhibition and photodamage [ 60 , 67 ]. Plant productivity is described by the photochemical efficacy of the absorbed amount of light energy [ 68 ]. Breeding for improved photosynthesis and light energy use in crops is a manageable and a useful shorter-term addition to genetic engineering to enhance crop potential [ 69 ].…”

3D point cloud of normalized difference vegetation index (NDVI) of segmented fruit and leaves in apple production

“…The copyright holder for this this version posted October 26, 2022. ; https://doi.org/10.1101/2022.10.24.513567 doi: bioRxiv preprint correlated with LA LiDAR over the measuring period, showing an R 2 of 0.89 with RMSE = 0.03 % at DAFB 65 and R² = 0.86 with RMSE = 0.06 % at DAFB 130 . The accuracy of the non-invasive analysis was limited due to occlusions and coinciding leaf surfaces as suggested in many plant species (Deery et al, 2021;Keller et al, 2022). However, such data derived from LiDAR point clouds are informative for late hand thinning considering the leaf area to fruit ratio in crop load management (Penzel et al, 2021).…”

“…Three-dimensional (3D) vision systems, such as light detection and ranging (LiDAR) laser scanning may overcome the limitations of established point or 2D imaging methods (Gongal et al, 2018; Walsh et al, 2020b; Keller et al, 2022). So far, LiDAR is used in remote sensing application in arable farming and forestry due to its capability to provide 3-dimensional (3D) geometric information of vegetation in field conditions (Deery et al, 2021; Zhu et al, 2021).…”