TY - JOUR

T1 - Root and xylem anatomy varies with root length, root order, soil depth, and environment in intermediate wheatgrass (Kernza®) and alfalfa

AU - Clément, Corentin

AU - Schneider, Hannah M

AU - Dresbøll, Dorte Bodin

AU - Lynch, Jonathan P

AU - Thorup-Kristensen, Kristian

N1 - © The Author(s) 2022. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

PY - 2022

Y1 - 2022

N2 - BACKGROUND AND AIMS: Deep roots (i.e., > 1 m depth) are important for crops to access water when the topsoil is dry. Root anatomy and hydraulic conductance play important roles in the uptake of soil water, particularly water located deep in the soil. We investigated whether root and xylem anatomy vary as a function of root type, order and length or with soil depth in roots of two deep-rooted perennial crops: intermediate wheatgrass (Thinopyrum intermedium (Kernza ®)) and alfalfa (Medicago sativa). We linked the expression of these anatomical traits to the plant's capacity to take up water from deep soil layers.METHODS: Using laser ablation tomography, we compared the roots of the two crops for cortical area, number and size of metaxylem vessels and their Estimated Root Axial Hydraulic Conductance (ERAHCe). The deepest roots investigated were located at soil depths of 2.25 and at 3.5 m in the field and in rhizoboxes, respectively. Anatomical differences were characterized along 1-m long individual roots, among root types and orders as well as between environmental conditions.KEY RESULTS: For both crops, a decrease in the number, diameter, or both, of metaxylem vessels along individual root segments and with soil depth in the field resulted in a decrease in ERAHCe. Alfalfa, with a greater number of metaxylem vessels per root throughout the soil profile and, on average, a 4-fold greater ERAHCe, took up more water from the deep soil layers than intermediate wheatgrass. Root anatomical traits were significantly different across root types, classes and growth conditions.CONCLUSIONS: Root anatomical traits are important tools for the selection of crops with enhanced exploitation of deep soil water. The development and breeding of perennial crops for improved subsoil exploitation will be aided by greater understanding of root phenotypes linked to deep root growth and activity.

AB - BACKGROUND AND AIMS: Deep roots (i.e., > 1 m depth) are important for crops to access water when the topsoil is dry. Root anatomy and hydraulic conductance play important roles in the uptake of soil water, particularly water located deep in the soil. We investigated whether root and xylem anatomy vary as a function of root type, order and length or with soil depth in roots of two deep-rooted perennial crops: intermediate wheatgrass (Thinopyrum intermedium (Kernza ®)) and alfalfa (Medicago sativa). We linked the expression of these anatomical traits to the plant's capacity to take up water from deep soil layers.METHODS: Using laser ablation tomography, we compared the roots of the two crops for cortical area, number and size of metaxylem vessels and their Estimated Root Axial Hydraulic Conductance (ERAHCe). The deepest roots investigated were located at soil depths of 2.25 and at 3.5 m in the field and in rhizoboxes, respectively. Anatomical differences were characterized along 1-m long individual roots, among root types and orders as well as between environmental conditions.KEY RESULTS: For both crops, a decrease in the number, diameter, or both, of metaxylem vessels along individual root segments and with soil depth in the field resulted in a decrease in ERAHCe. Alfalfa, with a greater number of metaxylem vessels per root throughout the soil profile and, on average, a 4-fold greater ERAHCe, took up more water from the deep soil layers than intermediate wheatgrass. Root anatomical traits were significantly different across root types, classes and growth conditions.CONCLUSIONS: Root anatomical traits are important tools for the selection of crops with enhanced exploitation of deep soil water. The development and breeding of perennial crops for improved subsoil exploitation will be aided by greater understanding of root phenotypes linked to deep root growth and activity.

U2 - 10.1093/aob/mcac058

DO - 10.1093/aob/mcac058

M3 - Journal article

C2 - 35468194

VL - 130

SP - 367

EP - 382

JO - Annals of Botany

JF - Annals of Botany

SN - 0305-7364

IS - 3

ER -