Developmental processes in tree root systems

1987 ◽  
Vol 17 (8) ◽  
pp. 761-767 ◽  
Author(s):  
M. P. Coutts
Keyword(s):  
Primary Structure ◽  
Lateral Roots ◽  
Secondary Growth ◽  
Local Environment ◽  
Root Systems ◽  
Herbaceous Species ◽  
Main Root ◽  
Secondary Thickening ◽  
Woody Root ◽  
Root Apices

Factors that influence the primary and secondary growth of roots are reviewed in relation to the development of the form of tree root systems. The development of occasional root apices of larger than average diameter is important because they form the main axes that undergo secondary thickening and become permanent members of the woody root system. The formation of these large apices is influenced by injury to, or reduced growth or dormancy of, the subtending main root axis and by proximity to the shoot. The base of the taproot and laterals is seen as a region strongly influenced by shoot activity, resulting in the formation of additional large root apices and enhanced secondary thickening to form the zone of rapid taper in trees, and in the formation of storage organs in some herbaceous species such as radish. The main root axes compete for assimilates and dominance is established between them at an early age. The unequal growth of competing lateral roots is influenced by the local environment of the roots of primary structure. The role of root apices on secondary growth is discussed with reference to work on herbaceous species. In trees the local environment has some direct effects on the root cambium, but such effects appear to be less important than the activity of the roots of primary structure. A hypothesis is developed incorporating the Japanese Pipe Theory for the allocation of assimilates for the secondary growth of tree roots.

scholarly journals The impact of morphometric characteristics of plants self-pollinated sunflower lines on its lodging

2020 ◽  
Vol 4 (184) ◽  
pp. 3-11
Author(s):  
B.N. Bochkaryov ◽  
◽  
N.V. Medvedeva ◽  
E.N. Ryzhenko ◽  
◽  
...  
Keyword(s):  
Root System ◽  
Lateral Roots ◽  
Root Systems ◽  
Morphometric Characteristics ◽  
Main Root ◽  
Lodging Resistance ◽  
Oil Crops ◽  
Russian Research Institute ◽  
Top Soil ◽  
The Impact

We carried out the research in 2018-2019 at the experimental station of V.S. Pustovoit All-Russian Research Institute of Oil Crops. The aim of the research is to study the effect of certain morphometric characteristics of the overground part of plants and the architectonics of the root system on the sunflower lodging. We found significant differences in the architectonics of root systems in 17 maternal lines of sunflower: we identified three morphotypes, differing in the number and thickness of lateral roots of the first and subsequent orders, located in the top soil. We identified the sunflower lines that have a root system with a well-developed main root and many lateral roots of various orders (type A), lines with a normally developed main root and a small number of lateral roots (type B), and lines with a poorly developed main root and few lateral roots in top soil (type C). We identified the presence of both low and high lodging in sunflower lines with different types of root systems. At the same time, there is a tendency towards higher lodging in lines with root system types B and C. The line SL12 3660 showed the maximum lodging resistance during two years of observations. It may be of interest for further work as a possible source of a lodging resistance trait.

scholarly journals Changes in Tree Root Architecture Resulting from Field Nursery Production Practices1

2020 ◽  
Vol 38 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Gary Watson ◽  
Angela Hewitt
Keyword(s):  
Root Architecture ◽  
Lateral Roots ◽  
Acer Rubrum ◽  
Root Systems ◽  
Root Pruning ◽  
Main Root ◽  
White Birch ◽  
Field Nursery ◽  
Nursery Production ◽  
Production Practices

Abstract Nursery production practices subject tree root systems to mechanical and environmental factors that are not imposed on plants regenerated naturally from seed. Architecture of undisturbed root systems of nine trees species commonly planted in urban landscapes was compared to root architecture of these tree species produced using common field nursery production practices. When young nursery production seedlings are root-pruned prior to replanting, the loss of the lower portion of the main root and lateral roots emerging from it, and initiation of adventitious roots from the cut end, alter the root system architecture. Nursery production plants have 7 to 48 percent fewer natural lateral roots that could develop into flare roots than undisturbed plants. New roots initiated from the cut end of the main root on nursery production plants can substitute for the loss of lateral roots, if accepted practices are followed. Root architecture of trees is established early. With minor exceptions attributed to the loss of small roots less than 1 mm diameter, there were no significant changes in the number of lateral roots over the 4 year period in both nursery production and undisturbed plants. This consistent number of roots also suggests that pruning the main root did not stimulate additional lateral roots above the pruning cut. Root architecture of liner stock produced in nurseries can be equivalent to undisturbed root systems. Index words: Structural roots, root pruning, bare root, root depth, taproot, root flare. Species used in this study: Norway maple (Acer platanoides L.); green ash (Fraxinus pennsylvanica Marsh.); littleleaf linden (Tilia cordata L.); red maple (Acer rubrum L.); European white birch (Betula pendula Roth.); Kentucky coffee tree (Gymnocladus dioicus L.); domestic apple (Malus spp.); red oak (Quercus rubra L.); Siberian elm (Ulmus pumila Jacq.).

scholarly journals Influence of Root Morphology on Ecological Slope Protection

2020 ◽  
Vol 198 ◽  
pp. 04036
Author(s):  
JI Xiaolei ◽  
XU Lanlan ◽  
YANG Guoping
Keyword(s):  
Root Morphology ◽  
Lateral Root ◽  
Lateral Roots ◽  
Soil Mass ◽  
Soil Reinforcement ◽  
Main Root ◽  
Protection Effect ◽  
Included Angle ◽  
Theoretical Support ◽  
Object Based

Ecological slope protection is of great importance for preventing the water and soil loss on bare slopes, improving the ecological environment, and realizing the sustainable ecosystem development. The root-soil composite slope consisting of homogenous soil mass and oleander root system was taken as the study object. Based on the mechanics principle of soil reinforcement by roots in ecological slope protection, the influences of the lateral root quantity of plants and included angle between main root and lateral root on the slope protection were investigated via the finite element (FE) software ABAQUS. The simulation results show that the larger the quantity of lateral roots, the more obvious the displacement reduction of the soil mass on the slope surface will be. The slope protection effect varies with the root morphology, the included angle between main root and lateral root is an important factor influencing the slope protection effect of plants, and the slope protection effect at included angle of 30° is apparently superior to that at 90°. The research results can provide a theoretical support for the plant selection in the ecological slope protection.

scholarly journals Root biomass of beech as a factor influencing the wind tree stability 

2019 ◽  
Vol 48 (No. 12) ◽  
pp. 549-564 ◽  
Author(s):  
J. Kodrík ◽  
M. Kodrík
Keyword(s):  
Root System ◽  
Groundwater Level ◽  
Negative Impact ◽  
Lateral Roots ◽  
Root Systems ◽  
Static Stability ◽  
Soil Conditions ◽  
Tree Stability ◽  
Ground Biomass ◽  
Below Ground

Beech is, thanks to its root system, in general considered to be a wind-resistant woody plant species. Nevertheless, the research on beech root systems has revealed that it is not possible to mechanically divide the woody plants into deep rooted and shallow rooted, because their root systems are modified according to various stand conditions. The root system shape, growth and development are mostly influenced by soil conditions and groundwater level. In the case of a high groundwater level beech root systems do not form tap roots and the lateral roots are rather thin and weak. Important factor for the tree static stability is number of roots with diameter 3–10 cm. The most important for the tree stability are roots with diameter over 10 cm. Wood-destroying fungi have strong negative impact on tree static stability. There are differences between beech below-ground biomass growing in soils rich in nutrients and poor in nutrients. The total below-ground biomass of the beech stands poor in nutrients is higher.

Lateral Root Pruning of Sitka Spruce and Western Hemlock Seedlings

1972 ◽  
Vol 2 (3) ◽  
pp. 223-227 ◽  
Author(s):  
S. Eis ◽  
J. R. Long
Keyword(s):  
Lateral Root ◽  
Lateral Roots ◽  
Root Systems ◽  
Growing Season ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Short Length ◽  
Western Hemlock ◽  
Root Pruning

Roots of Sitka spruce (Picea sitchensis) and western hemlock (Tsugaheterophylla) seedlings were side pruned in nursery beds at semimonthly intervals to produce dense and compact root systems. Root pruning early in the growing season stimulated the growth of existing roots and also initiated new roots. The densest root systems were produced by pruning before the end of June. However, because of the short length of lateral roots on seedlings early in their second growing season, pruning equidistant between rows 18 cm apart was ineffective. The best compromise appeared to be to prune spruce at the beginning of July, and hemlock around the middle of July. Earlier pruning equidistant between rows can be effective on larger seedlings during their third growing season. If early pruning is carried out on 2 + 0 seedlings, a pruning distance of about 6 cm from the row is recommended.

Bayoud disease of date palm: ultrastructure of root infection through pneumatodes

1986 ◽  
Vol 64 (8) ◽  
pp. 1703-1711 ◽  
Author(s):  
Rosa Belarbi-Halli ◽  
François Mangenot
Keyword(s):  
Cell Walls ◽  
Date Palm ◽  
Root Colonization ◽  
Phoenix Dactylifera ◽  
Root Infection ◽  
Intercellular Spaces ◽  
Main Root ◽  
The Matrix ◽  
Bayoud Disease ◽  
Root Apices

Young axenically grown plants of date palm, Phoenix dactylifera cv. Deglet-nour, were inoculated with Fusarium oxysporum Schl. f. sp. albedinis (Killian et Maire) Gordon, using conidia applied either on the pneumatode-free main root or on the pneumatodes of rootlets. After incubation for 15 days, infection was successful only in the latter case. The fungus grew inside the aerenchyma and clung tightly to the cell walls, the wartlike outgrowths, and the matrix present in the intercellular spaces. These structures were more or less altered in the presence of the hyphae. The fungus proceeded both intercellularly and intracellularly through the cortex. A dense hyphal sheet was observed facing the suberized endodermis, but the fungus somehow made its way into the stele. Penetrations of thick-walled cells commonly occurred through pits. Root colonization was slower toward the root apices than toward the base. After 15 days, the fungus was present at least 8 cm above the inoculation point at the base of the root.

scholarly journals Morpho-anatomical features of underground systems in six Asteraceae species from the Brazilian Cerrado

2011 ◽  
Vol 83 (3) ◽  
pp. 981-992 ◽  
Author(s):  
Beatriz Appezzato-da-Glória ◽  
Graziela Cury
Keyword(s):  
Environmental Conditions ◽  
Lateral Roots ◽  
Adaptive Strategy ◽  
Herbaceous Species ◽  
Bud Bank ◽  
Brazilian Cerrado ◽  
Neotropical Savanna ◽  
Anatomical Features ◽  
Paulo State ◽  
Vegetation Regeneration

In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. This study aims to analyse the morpho-anatomy of underground systems of six species of Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner and Vernonia megapotamica Spreng.), to describe these structures and to verify the occurrence and origin of shoot buds, and to analyse the presence of reserve substances. Individuals sampled in Cerrado areas in São Paulo State showed thick underground bud-bearing organs, with adventitious or lateral roots and presence of fructans. Xylopodium was found in all studied species, except for Trixis nobilis, which had stem tuber. The presence of fructans as reserve, and the capacity of structures in the formation of buds indicate the potential of herbaceous species of Asteraceae in forming a viable bud bank for vegetation regeneration in the Brazilian Cerrado.

scholarly journals GLO-Roots: an imaging platform enabling multidimensional characterization of soil-grown root systems

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Rubén Rellán-Álvarez ◽  
Guillaume Lobet ◽  
Heike Lindner ◽  
Pierre-Luc Pradier ◽  
Jose Sebastian ◽  
...  
Keyword(s):  
Gene Expression ◽  
Imaging System ◽  
Expression Patterns ◽  
Local Environment ◽  
Root Systems ◽  
Root System Architecture ◽  
Spatial Integration ◽  
Adaptive Responses ◽  
Physiological Relevance ◽  
Great Utility

Root systems develop different root types that individually sense cues from their local environment and integrate this information with systemic signals. This complex multi-dimensional amalgam of inputs enables continuous adjustment of root growth rates, direction, and metabolic activity that define a dynamic physical network. Current methods for analyzing root biology balance physiological relevance with imaging capability. To bridge this divide, we developed an integrated-imaging system called Growth and Luminescence Observatory for Roots (GLO-Roots) that uses luminescence-based reporters to enable studies of root architecture and gene expression patterns in soil-grown, light-shielded roots. We have developed image analysis algorithms that allow the spatial integration of soil properties, gene expression, and root system architecture traits. We propose GLO-Roots as a system that has great utility in presenting environmental stimuli to roots in ways that evoke natural adaptive responses and in providing tools for studying the multi-dimensional nature of such processes.

Modeling in-situ pine root decomposition using data from a 60-year chronosequence

2002 ◽  
Vol 32 (9) ◽  
pp. 1675-1684 ◽  
Author(s):  
Kim H Ludovici ◽  
Stanley J Zarnoch ◽  
Daniel D Richter
Keyword(s):  
Loblolly Pine ◽  
Lateral Root ◽  
Lateral Roots ◽  
Nutrient Release ◽  
Root Systems ◽  
Root Decomposition ◽  
Good Precision ◽  
Clear Cut ◽  
Stump Diameter

Because the root system of a mature pine tree typically accounts for 20–30% of the total tree biomass, decomposition of large lateral roots and taproots following forest harvest and re-establishment potentially impact nutrient supply and carbon sequestration in pine systems over several decades. If the relationship between stump diameter and decomposition of taproot and lateral root material, i.e., wood and bark, can be quantified, a better understanding of rates and patterns of sequestration and nutrient release can also be developed. This study estimated decomposition rates from in-situ root systems using a chronosequence approach. Nine stands of 55- to 70-year-old loblolly pine (Pinus taeda L.) that had been clear-cut 0, 5, 10, 20, 25, 35, 45, 55, and 60 years ago were identified on well-drained Piedmont soils. Taproot and lateral root systems were excavated, measured, and weighed. Although more than 50% of the total root mass decomposed during the first 10 years after harvest, field excavations recovered portions of large lateral roots (>5 cm diameter) and taproots that persisted for more than 35 and 60 years, respectively. Results indicate that decomposition of total root biomass, and its component parts, from mature, clear-cut loblolly pine stands, can be modeled with good precision as a function of groundline stump diameter and years since harvest.

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