根の深さを測定する新しい方法は、より回復力のある作物につながるかもしれない(Novel method to measure root depth may lead to more resilient crops)

2024-03-20

2024-03-19 ペンシルベニア州立大学(PennState)

ペンシルバニア州立大学の研究者は、新しいハイテクツールを開発しました。このツールは、X線蛍光分光法を使用して葉をスキャンすることで植物の根の深さを正確に推定する方法です。この方法は、根が到達する深さに応じて葉に化学元素を取り込むことを認識し、葉の化学元素と根の深さの間に相関があることを利用しています。この新技術は、作物が乾燥に耐え、窒素を取り込み、土壌中の炭素をより深く蓄積する方法を変える可能性があります。これにより、植物の根の深さを発掘する必要がなくなり、植物の品種改良プロセスが迅速化されます。

＜関連情報＞

LEADER（Leaf Element Accumulation from DEep Roots）：圃場での根の深さを推定する非破壊表現型プラットフォーム LEADER (Leaf Element Accumulation from DEep Roots): A nondestructive phenotyping platform to estimate rooting depth in the field

Meredith T. Hanlon, Kathleen M. Brown, Jonathan P. Lynch
Crop Science Published: 27 November 2023
DOI:https://doi.org/10.1002/csc2.21149

Abstract

Deeper rooted crops are an avenue to increase plant water and nitrogen uptake under limiting conditions and increase long-term soil carbon storage. Measuring rooting depth, however, is challenging due to the destructive, laborious, or imprecise methods that are currently available. Here, we present LEADER (Leaf Element Accumulation from DEep Roots) as a method to estimate in-field root depth of maize plants. We use both X-ray fluorescence (XRF) spectroscopy and ICP-OES (inductively coupled plasma optical emission spectroscopy) to measure leaf elemental content and relate this to metrics of root depth. Principal components of leaf elemental content correlate with measures of root length in four genotypes (R² = 0.8 for total root length), and we use linear discriminant analysis to classify plants as having different metrics related to root depth across four field sites in the United States. We can correctly classify the plots with the longest root length at depth (deeper than 30 or 40 cm) with high accuracy (accuracy >0.6) at two of our field sites (Hancock, WI and Rock Spring, PA). We also use strontium (Sr) as a tracer element in both greenhouse and field studies, showing that elemental accumulation of Sr in leaf tissue can be measured with XRF and can estimate root depth. We propose the adoption of LEADER as a tool for measuring root depth in different plant species and soils. LEADER is faster and easier than any other methods that currently exist and could allow for extensive study and understanding of deep rooting.