Fu Peng, Meacham-Hensold Katherine, Siebers Matthew H, Bernacchi Carl J
Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
J Exp Bot. 2021 Feb 24;72(4):1295-1306. doi: 10.1093/jxb/eraa537.
Improving photosynthesis is considered a promising way to increase crop yield to feed a growing population. Realizing this goal requires non-destructive techniques to quantify photosynthetic variation among crop cultivars. Despite existing remote sensing-based approaches, it remains a question whether solar-induced fluorescence (SIF) can facilitate screening crop cultivars of improved photosynthetic capacity in plant breeding trials. Here we tested a hypothesis that SIF yield rather than SIF had a better relationship with the maximum electron transport rate (Jmax). Time-synchronized hyperspectral images and irradiance spectra of sunlight under clear-sky conditions were combined to estimate SIF and SIF yield, which were then correlated with ground-truth Vcmax and Jmax. With observations binned over time (i.e. group 1: 6, 7, and 12 July 2017; group 2: 31 July and 18 August 2017; and group 3: 24 and 25 July 2018), SIF yield showed a stronger negative relationship, compared with SIF, with photosynthetic variables. Using SIF yield for Jmax (Vcmax) predictions, the regression analysis exhibited an R2 of 0.62 (0.71) and root mean square error (RMSE) of 11.88 (46.86) μmol m-2 s-1 for group 1, an R2 of 0.85 (0.72) and RMSE of 13.51 (49.32) μmol m-2 s-1 for group 2, and an R2 of 0.92 (0.87) and RMSE of 15.23 (30.29) μmol m-2 s-1 for group 3. The combined use of hyperspectral images and irradiance measurements provides an alternative yet promising approach to characterization of photosynthetic parameters at plot level.
提高光合作用被认为是增加作物产量以养活不断增长人口的一种有前景的方法。要实现这一目标，需要采用非破坏性技术来量化作物品种间的光合变异。尽管现有的基于遥感的方法，但太阳诱导荧光（SIF）能否在植物育种试验中促进筛选光合能力提高的作物品种仍是一个问题。在这里，我们测试了一个假设，即SIF产量而非SIF与最大电子传递速率（Jmax）有更好的关系。将晴空条件下的时间同步高光谱图像和太阳辐照光谱相结合，以估算SIF和SIF产量，然后将其与地面实测的Vcmax和Jmax相关联。通过对观测数据按时间进行分组（即第1组：2017年7月6日、7日和12日；第2组：2017年7月31日和8月18日；第3组：2018年7月24日和25日），与SIF相比，SIF产量与光合变量呈现出更强的负相关关系。使用SIF产量预测Jmax（Vcmax），第1组的回归分析显示R2为0.62（0.71），均方根误差（RMSE）为11.88（46.86）μmol m-2 s-1；第2组的R2为0.85（0.72），RMSE为13.51（49.32）μmol m-2 s-1；第3组的R2为0.92（0.87），RMSE为15.23（30.29）μmol m-2 s-1。高光谱图像和辐照度测量的联合使用为在小区水平上表征光合参数提供了一种替代但有前景的方法。
