Leaf excision has minimal impact on photosynthetic parameters across crop functional types

Abstract

Photosynthesis is increasingly becoming a recognised target for crop improvement. Phenotyping photosynthesis-related traits on field-grown material is a key bottleneck to progress here due to logistical barriers and short measurement days. Many studies attempt to overcome these challenges by phenotyping excised leaf material in the laboratory. To date there are no demonstrated examples of the representative nature of photosynthesis measurements performed on excised leaves relative to intact leaves in crops. Here, we tested whether standardised leaf excision on the day prior to phenotyping impacted a range of common photosynthesis-related traits across crop functional types using tomato (C3-dicot), barley (C3-monocot), and maize (C4-monocot). Potentially constraining aspects of leaf physiology that could be forecasted to impair photosynthesis in excised leaves, namely leaf water potential and abscisic acid accumulation, were not different between intact and excised leaves. We also observed non-significant differences in spectral reflectance and chlorophyll fluorescence traits between the treatments across the three species. However, we did observe some significant differences between gas exchange and photosynthetic capacity associated traits across all three species. This study represents a useful reference for those who perform measurements of this nature and the differences reported should be considered in associated experimental design and statistical analyses. HighlightAcross the main photosynthesis functional types (C3-dicot, C3-monot, and C4-monot) of major crops (tomato, barley, and maize), measurements of photosynthetic parameters demonstrate few, but important, differences when measured on excised relative to intact leaves.

Plant phenotyping relevance

切除葉と intact 葉で光合成関連形質の測定結果を比較し、葉切除を用いた表現型取得手法の代表性・妥当性を検証しているため、単なる生物学的実験ではなく方法検証が中心である。

Code and data availability

The supplied blocks describe the paper's phenotyping methods (gas exchange, hyperspectral reflectance, chlorophyll fluorescence, ABA, water potential) and statistical analyses in R, but contain no data availability statement, no public dataset deposit, and no author code/workflow URL. The only code mentioned (plantecop

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