scholarly journals High-resolution 4D spatiotemporal analysis reveals the contributions of local growth dynamics to contrasting maize root architectures

2018 ◽  
Author(s):  
Ni Jiang ◽  
Eric Floro ◽  
Adam L. Bray ◽  
Benjamin Laws ◽  
Keith E. Duncan ◽  
...  
Keyword(s):  
Root Growth ◽  
Root System ◽  
Growth Dynamics ◽  
Root Systems ◽  
Growth Patterns ◽  
Maize Root ◽  
Global Features ◽  
Long Distance ◽  
Local Root ◽  
The Many

ABSTRACTRoot systems are branched networks that develop from simple growth properties of their individual roots. Yet a mature maize root system has many thousands of roots that each interact with soil structures, water and nutrient patches, and microbial ecologies in the micro-environments surrounding each root tip. Although the plasticity of root growth to these and other environmental factors is well known, how the many local processes contribute over time to global features of root system architecture is hardly understood. We employ an automated 3D root imaging pipeline to capture the growth of maize roots every four hours throughout seven days of seedling development. We model the contrasting architectures of two maize inbred genotypes and their hybrid to derive key parameters that distinguish complex growth patterns as a function of time. The statistical characteristics of local root growth defined the global system properties despite a large range of trait values. “Computational dissection” of a single root from each root system identified differences in the size of the root branching zone and lateral branching densities, but not radial patterns, that drove the contrasting root architectures from seedling to maturity. X-ray imaging of mature field-grown root crowns showed that seedling growth trajectories persisted throughout development and could predict eventual architectures, suggesting a strong genetic basis. The work connects individual and systemwide scales of root growth dynamics, providing the means for a function-valued approach to understanding the genetic and genetic x environment conditioning of root growth that will enable breeding for enhanced root traits.SIGNIFICANCE STATEMENTWhen and where roots grow determines their ability to capture short-lived and patchy water and nutrient resources to support the aboveground organs of the plant. Roots have no known long-distance external sensing mechanisms, but form branched networks that blindly explore the soil and respond to encountered local stimuli. How global architectures form from the many thousands of these local responses, and how they are controlled genetically are major open questions. Here we quantify differences in local root growth patterns of two inbred genotypes of maize that control contrasting systemwide properties. Measurements at the seedling stage were highly correlated with the complex architectures of mature root systems, paving the way for the development of crops with greater resource uptake capacity.

scholarly journals Contemporary Concepts of Root System Architecture of Urban Trees

2010 ◽  
Vol 36 (4) ◽  
pp. 149-159
Author(s):  
Susan Day ◽  
P. Eric Wiseman ◽  
Sarah Dickinson ◽  
J. Roger Harris
Keyword(s):  
Built Environment ◽  
Root Growth ◽  
Root System ◽  
Root Architecture ◽  
Root Systems ◽  
Growth Patterns ◽  
Urban Trees ◽  
Rooting Depth ◽  
Similar Species ◽  
Urban Settings

Knowledge of the extent and distribution of tree root systems is essential for managing trees in the built environment. Despite recent advances in root detection tools, published research on tree root architecture in urban settings has been limited and only partially synthesized. Root growth patterns of urban trees may differ considerably from similar species in forested or agricultural environments. This paper reviews literature documenting tree root growth in urban settings as well as literature addressing root architecture in nonurban settings that may contribute to present understanding of tree roots in built environments. Although tree species may have the genetic potential for generating deep root systems (>2 m), rooting depth in urban situations is frequently restricted by impenetrable or inhospitable soil layers or by underground infrastructure. Lateral root extent is likewise subject to restriction by dense soils under hardscape or by absence of irrigation in dry areas. By combining results of numerous studies, the authors of this paper estimated the radius of an unrestricted root system initially increases at a rate of approximately 38 to 1, compared to trunk diameter; however, this ratio likely considerably declines as trees mature. Roots are often irregularly distributed around the tree and may be influenced by cardinal direction, terrain, tree lean, or obstacles in the built environment. Buttress roots, tap roots, and other root types are also discussed.

Effects of Temperature on Root Morphology and Ectendomycorrhizal Development in Pinusresinosa Ait.

1975 ◽  
Vol 5 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Hugh E. Wilcox ◽  
Ruth Ganmore-Neumann
Keyword(s):  
Root Growth ◽  
Root System ◽  
Root Morphology ◽  
Root Systems ◽  
Second Order ◽  
Root Temperature ◽  
First Order ◽  
Effects Of Temperature

Seedlings of Pinusresinosa were grown at root temperatures of 16, 21 and 27 °C, both aseptically and after inoculation with the ectendomycorrhizal fungus BDG-58. Growth after 3 months was significantly influenced by the presence of the fungus at all 3 temperatures. The influence of the fungus on root growth was obscured by the effects of root temperature on morphology. The root system at 16 and at 21 °C possessed many first-order laterals with numerous, well developed second-order branches, but those at 27 °C had only a few, relatively long, unbranched first-order laterals. Although the root systems of infected seedlings were larger, the fungus increased root growth in the same pattern as determined by the temperature.

scholarly journals MARSHAL, a novel tool for virtual phenotyping of maize root system hydraulic architectures

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Félicien Meunier ◽  
Adrien Heymans ◽  
Xavier Draye ◽  
Valentin Couvreur ◽  
Mathieu Javaux ◽  
...  
Keyword(s):  
Root System ◽  
Web Application ◽  
Root Traits ◽  
Root Systems ◽  
R Package ◽  
Maize Root ◽  
Model Parameters ◽  
System Modelling ◽  
Architecture Model ◽  
System Models

Abstract Functional-structural root system models combine functional and structural root traits to represent the growth and development of root systems. In general, they are characterized by a large number of growth, architectural and functional root parameters, generating contrasted root systems evolving in a highly non-linear environment (soil, atmosphere), which makes the link between local traits and functioning unclear. On the other end of the root system modelling continuum, macroscopic root system models associate to each root system a set of plant-scale, easily interpretable parameters. However, as of today, it is unclear how these macroscopic parameters relate to root-scale traits and whether the upscaling of local root traits is compatible with macroscopic parameter measurements. The aim of this study was to bridge the gap between these two modelling approaches. We describe here the MAize Root System Hydraulic Architecture soLver (MARSHAL), a new efficient and user-friendly computational tool that couples a root architecture model (CRootBox) with fast and accurate algorithms of water flow through hydraulic architectures and plant-scale parameter calculations. To illustrate the tool’s potential, we generated contrasted maize hydraulic architectures that we compared with root system architectural and hydraulic observations. Observed variability of these traits was well captured by model ensemble runs. We also analysed the multivariate sensitivity of mature root system conductance, mean depth of uptake, root system volume and convex hull to the input parameters to highlight the key model parameters to vary for virtual breeding. It is available as an R package, an RMarkdown pipeline and a web application.

Root growth of wheat. I. Early patterns of multiplication and extension of wheat roots including effects of levels of nitrogen, phosphorus and potassium

1976 ◽  
Vol 27 (2) ◽  
pp. 183 ◽  
Author(s):  
D Tennant
Keyword(s):  
Root Growth ◽  
Root System ◽  
Root Systems ◽  
Relative Increase ◽  
Seminal Root ◽  
Root Numbers ◽  
Nodal Root ◽  
Rate Of Increase ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus

Wheat root growth was followed to 30 days from planting in wheat supplied with standard, twofold, half and nil levels of nitrogen, phosphorus and potassium. Root numbers and lengths followed consistent patterns of increase in the seminal and nodal root systems of all treatments. Most root components demonstrated their highest rates of relative increase in length and number immediately after first appearance. Within a few days this decreased to a constant rate of increase which continued until the end of the experiment. Rates during the stages of constant relative increase were higher with increasing order of lateral, and the same for all treatments, except when nutrient deficiency seriously suppressed root growth. Potassium deficiency stopped root growth completely within 10–12 days of planting. Nitrogen and phosphorus deficiencies gave increasing delays in root component appearance with increasing order of lateral. Increasing suppression of seminal lateral numbers and a severe suppression of nodal root growth followed. Lower root numbers caused by nitrogen deficiency were compensated by greater lateral lengths in the seminal but not the nodal root systems. Some reduction in root growth resulted from application of the half and twofold levels of nitrogen, phosphorus and potassium. All responses to applied nutrient levels were more obvious with increasing order of lateral and with the nodal rather than seminal root systems. The nodal root system reflected plant response better than the seminal root system.

EFFECTIVE SOIL VOLUME AND ITS IMPORTANCE TO ROOT AND TOP GROWTH OF PLANTS

1967 ◽  
Vol 47 (3) ◽  
pp. 163-174 ◽  
Author(s):  
D. S. Stevenson
Keyword(s):  
Root Growth ◽  
Water Supply ◽  
Root System ◽  
Experimental Work ◽  
Root Systems ◽  
Daily Water ◽  
Soil Volume ◽  
Individual Root

Root and top growth of clover, wheat, and sunflowers varied consistently and quantitatively with changing soil volumes.A definition for effective soil volume is given and discussed in terms of root growth and root densities. The postulate is made that in root systems above a certain density each individual root can interfere with the daily water supply of nearby roots and hence restrict the growth of the whole root system and plant. The theoretical geometric proportions of this interference are discussed. The importance of soil volume in experimental work is indicated.

scholarly journals An approach to modelling tree root architecture in virtual urban growing conditions

2021 ◽  
Author(s):  
Justin Miron
Keyword(s):  
Root Growth ◽  
Root System ◽  
Root Architecture ◽  
Root Systems ◽  
System Structure ◽  
Tree Roots ◽  
System Architectures ◽  
Architecture Model ◽  
Investigation Methods ◽  
Urban Conditions

Understanding the architecture of tree roots is an important component of urban forestry management practice. Tree roots are structurally and functionally important to the survival of trees, and this can be even more so in urban environments where underground space for roots is limited. Tree root architecture models can provide a complementary approach to traditional on-site field investigation methods. Root architecture models are unique in that they can simulate the spatial arrangements of root system structure explicitly, and allow investigators to create hypothetical simulations to test their assumptions about what may be driving root growth. The use of root architecture models in the literature is extensive and may be applied in diverse streams of investigation, but their application to tree root systems is less common. This research demonstrates a root architecture model, Rootbox, as a case study in the application of plant architecture models to simulate tree root growth in urban conditions. Model parameterization was based on conformity of root simulations to tree root architecture reported in the literature. The model is deployed in four hypothetical urban soil scenarios, which are representative of planting sites commonly observed in urban settings. The analysis demonstrates that plausible tree root system architectures – specifically, commonly observed growth attributes - can be produced by Rootbox, but only after several adaptive changes to both the source code/model design are made. Custom soil models can integrate with the simulation to represent urban conditions by modifying both the growth direction and elongation of portions of the root architecture, and thus offer greater control over the output architecture. Rootbox offers a flexible method of simulating the architecture of tree root systems, but further research should focus on optimizing the model’s parameters and functions to enable greater user control over model output.

scholarly journals Root Growth Near Vertical Root Barriers after Seven Years

2009 ◽  
Vol 35 (1) ◽  
pp. 23-26
Author(s):  
E. Thomas Smiley ◽  
Liza Wilkinson ◽  
Bruce Fraedrich
Keyword(s):  
Root Growth ◽  
Root System ◽  
Growth Patterns ◽  
Root Barriers ◽  
Quercus Phellos ◽  
Two Sides

Vertical root barriers are used to redirect root growth to greater depths in the soil, thus reducing damage to the sidewalks. This study was conducted to examine root growth patterns near a variety of vertical root barriers. Thirty willow oaks (Quercus phellos) were planted in November 2000 and one of the following treatments was installed on two sides of each tree: Biobarrier, DeepRoot Universal Barrier, DeepRoot Universal Barrier with Spin Out, Tex-R, Typar Geotextile 3801, or a no-barrier control. In March 2007, the second 15-tree block was excavated to reveal the root system outside the barrier. All five root barriers significantly reduced the amount of root growth compared with the control trees. There were no differences among the products tested.

Root mapping of three tropical pasture species using 32P

1969 ◽  
Vol 9 (39) ◽  
pp. 445 ◽  
Author(s):  
RA Bray ◽  
JB Hacker ◽  
DE Byth
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Lateral Root ◽  
Sandy Loam ◽  
Lateral Roots ◽  
Root Systems ◽  
Growth Patterns ◽  
Constant Rate ◽  
Initial Root

Root growth patterns of Glycine javanica, Setaria anceps, and Medicago sativa were studied by uptake of 32P from a sandy loam. Placement of isotope was through permanently positioned PVC conduit on a grid over a 90� quadrant of the root system. Detection of radioactivity was in in situ plant material. Lucerne had strong initial root development but was slow to form lateral roots. Glycine and Setaria had quite similar root systems although Setaria had more rapid vertical root development than Glycine. Both these species had strong lateral root systems. When a regression of minimum root length against time was calculated, lateral root growth was shown to be independent of depth and distance from the plant, suggesting that roots behave as if growing from a point source in random directions at a constant rate. This rate was the same for all species. There were also indications of strong vertical root systems in lucerne and Setaria.

Decision Making within Plant Root Systems

1996 ◽  
Author(s):  
Yoav Waisel ◽  
Bobbie McMichael ◽  
Amram Eshel
Keyword(s):  
Root System ◽  
System Architecture ◽  
Plant Root ◽  
Lateral Roots ◽  
Root Systems ◽  
Root System Architecture ◽  
Growth Patterns ◽  
Soil Conditions ◽  
Stage Of Development ◽  
Root Types

Architecture of a root system is the expression of the potential of various root types to branch, to grow and to coordinate with other plant organs, under the specific limitations of the environmental conditions. The present investigation has proven the following points. 1) Genotypes with different types of root systems were identified. The growth patterns of their roots and the distribution of laterals along their main axes were recorded. 2) The patterns of development of the root systems of four cotton genotypes, throughout the entire life cycle of the plants, were described, even at such a late stage of development when the total length of the roots exceeded two kilometers. To the best of our knowledge, this is the first time that an analysis of this type is accomplished. 3) The development of root systems under restrictive soil conditions were compared with those that have developed under the non-restrictive conditions of aeroponics. Results indicate that in the absence of the mechanical impedance of the soil, cotton plants develop single roots that reach the length of 6 m, and have a total root length of 2000 m. Thus, root growth is strongly inhibited by the soil, with some root types being inhibited more than others. 4) One of the important decisions, in constructing an operational root system architecture of mature plants, is the shift of the balance between various root fractions in favor of the very fine roots. 5) Root system architecture is determined, in part, by the sites of initiation of the lateral roots. This is determined genetically by the number of xylem archs and by the totuosity of the stele. Selection for such traits should be sought.

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