Root systems of major tropical root and tuber crops: Root architecture, size, and growth and initiation of storage organs

2020 ◽  
pp. 1-25 ◽  
Author(s):  
Peter J. Gregory ◽  
Tobias Wojciechowski
Keyword(s):  
Root Architecture ◽  
Root Systems ◽  
Storage Organs ◽  
Tuber Crops

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.

scholarly journals Root architecture simulation improves the inference from seedling root phenotyping towards mature root systems

2017 ◽  
Vol 68 (5) ◽  
pp. 965-982 ◽  
Author(s):  
Jiangsan Zhao ◽  
Gernot Bodner ◽  
Boris Rewald ◽  
Daniel Leitner ◽  
Kerstin A. Nagel ◽  
...  
Keyword(s):  
Root Architecture ◽  
Root Systems ◽  
Seedling Root ◽  
Root Phenotyping ◽  
Architecture Simulation ◽  
Mature Root

scholarly journals Toward Marker-assisted Breeding for Root Architecture Traits in Southern Highbush Blueberry

2016 ◽  
Vol 141 (5) ◽  
pp. 414-424 ◽  
Author(s):  
Gerardo H. Nunez ◽  
Hilda Patricia Rodríguez-Armenta ◽  
Rebecca L. Darnell ◽  
James W. Olmstead
Keyword(s):  
Root Growth ◽  
Root Architecture ◽  
Root Systems ◽  
Vaccinium Corymbosum ◽  
Lower Percentage ◽  
Soil Conditions ◽  
Growth Substrate ◽  
Family Pedigree ◽  
Southern Highbush ◽  
Trait Associations

Root growth and root system architecture (RSA) are affected by edaphic and genetic factors and they can impact plant growth and farm profitability. Southern highbush blueberries [SHBs (Vaccinium corymbosum hybrids)] develop shallow, fibrous root systems, and exhibit a preference for acidic soils where water and ammonium are readily available. The amendments used to create these soil conditions negatively affect the profitability of SHB plantations. Hence, breeding for RSA traits has been suggested as an alternative to soil amendments. Vaccinium arboreum is a wild species that is used in SHB breeding. V. arboreum exhibits greater drought tolerance and broader soil pH adaptation than SHB, and—according to anecdotal evidence—it develops deep, taproot-like root systems. The present study constitutes the first in-depth study of the RSA of Vaccinium species with the intention of facilitating breeding for RSA traits. Root systems were studied in rhizotron-grown seedling families. In separate experiments, we tested the effect that growth substrate and family pedigree can have on root growth and RSA. Subsequently, a genotyping by sequence approach was used to develop single nucleotide polymorphism (SNP) markers that could be used along with the phenotyping method to investigate the heritability of RSA traits and look for marker-trait associations. We found that RSA is affected by growth substrate and family pedigree. In addition, we found that V. arboreum exhibited greater maximum root depth and a lower percentage of roots in the top 8 cm of soil than SHB, and interspecific hybrids generally exhibited intermediate phenotypes. Also, we found that RSA traits exhibit moderate to low heritability and genetic correlations among them. Finally, we found 59 marker-trait associations. Among these markers, 37 were found to be located in exons, and 16 of them were annotated based on protein homology with entries in National Center for Biotechnology Information (NCBI) GenBank. Altogether, the present study provides tools that can be used to breed for root architecture traits in SHB.

scholarly journals Simulating rhizodeposition patterns around growing and exuding root systems

2021 ◽  
Author(s):  
Magdalena Landl ◽  
Adrian Haupenthal ◽  
Daniel Leitner ◽  
Eva Kroener ◽  
Doris Vetterlein ◽  
...  
Keyword(s):  
Root Architecture ◽  
Three Dimensional ◽  
Temporal Distribution ◽  
Root Systems ◽  
Distribution Patterns ◽  
Three Dimensions ◽  
Root Branching ◽  
Architecture Model ◽  
Spatio Temporal ◽  
Model Approach

1AbstractIn this study, we developed a novel model approach to compute the spatio-temporal distribution patterns of rhizodeposits around growing root systems in three dimensions. This model approach allows us for the first time to study the evolution of rhizodeposition patterns around complex three-dimensional root systems. Root systems were generated using the root architecture model CPlantBox. The concentration of rhizodeposits at a given location in the soil domain was computed analytically. To simulate the spread of rhizodeposits in the soil, we considered rhizodeposit release from the roots, rhizodeposit diffusion into the soil, rhizodeposit sorption to soil particles, and rhizodeposit degradation by microorganisms. To demonstrate the capabilities of our new model approach, we performed simulations for the two example rhizodeposits mucilage and cit-rate and the example root system Vicia faba. The rhizodeposition model was parameterized using values from the literature. Our simulations showed that the rhizosphere soil volume with rhizodeposit concentrations above a defined threshold value (i.e., the rhizodeposit hotspot volume), exhibited a maximum at intermediate root growth rates. Root branching allowed the rhizospheres of individual roots to overlap, resulting in a greater volume of rhizodeposit hotspots. This was particularly important in the case of citrate, where overlap of rhizodeposition zones accounted for more than half of the total rhizodeposit hotspot volumes. Coupling a root architecture model with a rhizodeposition model allowed us to get a better understanding of the influence of root architecture as well as rhizodeposit properties on the evolution of the spatio-temporal distribution patterns of rhizodeposits around growing root systems.

Advances in the understanding of nitrogen (N) uptake by plant roots

2021 ◽  
pp. 303-320
Author(s):  
Malcolm J. Hawkesford ◽  
◽  
William R. Whalley ◽  
Keyword(s):  
Root Architecture ◽  
Crop Yields ◽  
N Uptake ◽  
Crop Improvement ◽  
Root Systems ◽  
Stress Factors ◽  
Fertilizer N ◽  
Abiotic Stress Factors ◽  
Factors Influencing ◽  
Crop Root

Efficient use of nitrogen (N) by plants and particularly crops, is of global importance. In agriculture, high crop yields and protein content depend upon extensive N-inputs, however fertilizer N is costly to the farmer, and overuse can be damaging to the environment. A critical component of optimised usage is efficient capture by crop root systems. This chapter focusses on principal mechanisms of uptake and factors influencing efficiency. Genetic variation in root architecture and in an array of transporters known to be involved in nitrogen capture is detailed. The impacts of abiotic stress factors such as soil structure are described. Finally prospects and opportunities for crop improvement are discussed.

scholarly journals New roots for agriculture: exploiting the root phenome

2012 ◽  
Vol 367 (1595) ◽  
pp. 1598-1604 ◽  
Author(s):  
Jonathan P. Lynch ◽  
Kathleen M. Brown
Keyword(s):  
Root Architecture ◽  
Fitness Landscape ◽  
Root Systems ◽  
Developing Nations ◽  
Soil Resource ◽  
Resource Capture ◽  
Soil Exploration ◽  
New Research ◽  
Training Modalities ◽  
And Training

Recent advances in root biology are making it possible to genetically design root systems with enhanced soil exploration and resource capture. These cultivars would have substantial value for improving food security in developing nations, where yields are limited by drought and low soil fertility, and would enhance the sustainability of intensive agriculture. Many of the phenes controlling soil resource capture are related to root architecture. We propose that a better understanding of the root phenome is needed to effectively translate genetic advances into improved crop cultivars. Elementary, unique root phenes need to be identified. We need to understand the ‘fitness landscape’ for these phenes: how they affect crop performance in an array of environments and phenotypes. Finally, we need to develop methods to measure phene expression rapidly and economically without artefacts. These challenges, especially mapping the fitness landscape, are non-trivial, and may warrant new research and training modalities.

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 Nutritional Studies of Christmas Bell

HortScience ◽  
1990 ◽  
Vol 25 (11) ◽  
pp. 1401-1402
Author(s):  
G.P. Lamont ◽  
G.C. Cresswell ◽  
G.J. Griffith
Keyword(s):  
Controlled Release ◽  
Root Systems ◽  
Liquid Fertilizer ◽  
Controlled Release Fertilizer ◽  
Liquid Feed ◽  
Storage Organs ◽  
Nutritional Studies ◽  
Fibrous Roots ◽  
Pale Green ◽  
Blandfordia Grandiflora

Eighteen-month-old seedlings of Christmas Bell (Blandfordia grandiflora Sm.) in 800-ml containers were top dressed with 8- to 9-month Osmocote controlled-release fertilizer 18N-2.6P-10K at 0, 0.625, 1.25, 2.5, 5.0, or 10 kg·m-3. Other plants were fertilized once or twice weekly with a complete liquid fertilizer supplying 100 mg N/liter based on an N : K ratio of either 1:0.6 or 1:1.5. The former ratio was the same as the Osmocote while the latter was the N : K ratio in tops of healthy wild-growing plants of B. grandiflora. The highest fresh weights occurred at the Osmocote rate of 5 kg·m-3 and with the once-weekly liquid feed of 1 N : 1.5 K ratio. Plants fertilized with low rates of Osmocote were pale green but had extensive root systems that were white and predominantly fibrous. As the rate of Osmocote was increased, plants became greener and produced smaller root systems in which fleshy storage organs were predominant over fibrous roots.

scholarly journals Bayesian inference of root architectural model parameters from synthetic field data

2021 ◽  
Author(s):  
Shehan Morandage ◽  
Eric Laloy ◽  
Andrea Schnepf ◽  
Harry Vereecken ◽  
Jan Vanderborght
Keyword(s):  
Bayesian Inference ◽  
Root System ◽  
Root Architecture ◽  
Root Systems ◽  
Zero Order ◽  
Model Parameters ◽  
Soil Core ◽  
Density Profiles ◽  
Root Parameters ◽  
Order Root

Abstract Background and aims Characterizing root system architectures of field-grown crops is challenging as root systems are hidden in the soil. We investigate the possibility of estimating root architecture model parameters from soil core data in a Bayesian framework. Methods In a synthetic experiment, we simulated wheat root systems in a virtual field plot with the stochastic CRootBox model. We virtually sampled soil cores from this plot to create synthetic measurement data. We used the Markov chain Monte Carlo (MCMC) DREAM(ZS) sampler to estimate the most sensitive root system architecture parameters. To deal with the CRootBox model stochasticity and limited computational resources, we essentially added a stochastic component to the likelihood function, thereby turning the MCMC sampling into a form of approximate Bayesian computation (ABC). Results A few zero-order root parameters: maximum length, elongation rate, insertion angles, and numbers of zero-order roots, with narrow posterior distributions centered around true parameter values were identifiable from soil core data. Yet other zero-order and higher-order root parameters were not identifiable showing a sizeable posterior uncertainty. Conclusions Bayesian inference of root architecture parameters from root density profiles is an effective method to extract information about sensitive parameters hidden in these profiles. Equally important, this method also identifies which information about root architecture is lost when root architecture is aggregated in root density profiles.

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