Field Competition Between Tall Morningglory and Soybean. II. Development and Distribution of Root Systems

Weed Science ◽  
1976 ◽  
Vol 24 (5) ◽  
pp. 454-460 ◽  
Author(s):  
H. D. Scott ◽  
L. R. Oliver
Keyword(s):  
Interspecific Competition ◽  
Root System ◽  
Intraspecific Competition ◽  
Root Length ◽  
Root Systems ◽  
Planting Density ◽  
Silt Loam ◽  
Soybean Root ◽  
Ipomoea Purpurea ◽  
Plant Densities

Studies of the development and distribution of root systems of intraspecific and interspecific competition were conducted between soybean [Glycine max.(L.) Merr. ‘Lee 68′] and tall morningglory [Ipomoea purpurea(L.) Roth]. Tall morningglory at three plant densities and soybean were grown for 2 yr on a Taloka silt loam. The greatest density of soybean and tall morningglory roots grown under intraspecific competition was in the surface 12 cm and in the center of the row. Greater values of root length and density were during the dryer season. The largest fraction of total root length at a given date also was in the surface 12 cm and decreased with depth. The fraction at a given depth was a dynamic property of the root system during the growing season. When compared with the soybean root system, tall morningglory roots were found at deeper depths and had greater root densities. Little expansion of the soybean root system was found after initiation of the soybean reproductive phase. During this phase, the tall morningglory root system was increasing at a faster rate of growth than the soybean root system. The greatest density of roots grown under interspecific competition also was in the surface 12 cm and at the center of the row. These values were less than those found under intraspecific competition. Root distribution and development are dynamic functions of growth stage, planting density, and plant species.

A biochemical study of BAS 517 using excised corn and soybean root systems

Weed Science ◽  
1999 ◽  
Vol 47 (1) ◽  
pp. 28-36
Author(s):  
Hwei-Yiing Li ◽  
Chester L. Foy
Keyword(s):  
Root System ◽  
Biochemical Study ◽  
Lipid Fraction ◽  
Root Systems ◽  
Water Soluble ◽  
Root Tips ◽  
Soybean Root ◽  
Corn Roots ◽  
Tracer Techniques ◽  
High Degree

The mode of action of BAS 517 in a susceptible plant species, corn, was investigated using an excised root system and14C-tracer techniques. The root system of a tolerant species, soybean, was used for comparison. When UL-14C- glucose was used as a precursor,14C incorporation into lipids was reduced in BAS 517-treated corn roots, although14C incorporation from UL-14C-glucose into lipids was relatively low. Inhibition of14C incorporation into water-soluble compounds was not definite because of a high degree of variability. Using14C-acetate as a precursor, 49, 43, and 34% of the recovered radioactivity was found in the lipid fractions of root tips treated with 0, 1.0, and 10 μM BAS 517, respectively. In nontreated soybean root tips, 47% of the recovered radioactivity was found in the lipid fraction compared to 49% in root tips treated with 10 μM BAS 517. Further analysis of lipids showed that BAS 517 inhibited the incorporation of14C from14C-acetate into phosphatidylethanolamine, a phospholipid, whereas the labeling of sterols in treated corn roots was not adversely affected. Acetyl CoA carboxylase extracted from root systems of corn and soybean showed different sensitivity to BAS 517, suggesting its role as the herbicide target site and as a basis for the selectivity.

scholarly journals Comparison of Root System Morphology of Cucurbit Rootstocks for Use in Watermelon Grafting

2018 ◽  
Vol 28 (5) ◽  
pp. 629-636 ◽  
Author(s):  
Matthew B. Bertucci ◽  
David H. Suchoff ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Christopher C. Gunter ◽  
...  
Keyword(s):  
Root System ◽  
Surface Area ◽  
Root Length ◽  
Dry Weight ◽  
Root Systems ◽  
Root Surface ◽  
Root Diameter ◽  
Root Surface Area ◽  
Diameter Class ◽  
Main Effect

Grafting of watermelon (Citrullus lanatus) is an established production practice that provides resistance to soilborne diseases or tolerance to abiotic stresses. Watermelon may be grafted on several cucurbit species (interspecific grafting); however, little research exists to describe root systems of these diverse rootstocks. A greenhouse study was conducted to compare root system morphology of nine commercially available cucurbit rootstocks, representing four species: pumpkin (Cucurbita maxima), squash (Cucurbita pepo), bottle gourd (Lagenaria siceraria), and an interspecific hybrid squash (C. maxima × C. moschata). Rootstocks were grafted with a triploid watermelon scion (‘Exclamation’), and root systems were compared with nongrafted (NG) and self-grafted (SG) ‘Exclamation’. Plants were harvested destructively at 1, 2, and 3 weeks after transplant (WAT), and data were collected on scion dry weight, total root length (TRL), average root diameter, root surface area, root:shoot dry-weight ratio, root diameter class proportions, and specific root length. For all response variables, the main effect of rootstock and rootstock species was significant (P < 0.05). The main effect of harvest was significant (P < 0.05) for all response variables, with the exception of TRL proportion in diameter class 2. ‘Ferro’ rootstock produced the largest TRL and root surface area, with observed values 122% and 120% greater than the smallest root system (‘Exclamation’ SG), respectively. Among rootstock species, pumpkin produced the largest TRL and root surface area, with observed values 100% and 82% greater than those of watermelon, respectively. These results demonstrate that substantial differences exist during the initial 3 WAT in root system morphology of rootstocks and rootstock species available for watermelon grafting and that morphologic differences of root systems can be characterized using image analysis.

scholarly journals Barley shoot biomass responds strongly to N:P stoichiometry and intraspecific competition, whereas roots only alter their foraging

2020 ◽  
Vol 453 (1-2) ◽  
pp. 515-528 ◽  
Author(s):  
Amit Kumar ◽  
Richard van Duijnen ◽  
Benjamin M. Delory ◽  
Rüdiger Reichel ◽  
Nicolas Brüggemann ◽  
...  
Keyword(s):  
Root System ◽  
Intraspecific Competition ◽  
Root Length ◽  
Root Biomass ◽  
Specific Root Length ◽  
Plant Performance ◽  
Shoot Biomass ◽  
P Availability ◽  
Soil Layers ◽  
N:P Stoichiometry

Abstract Aims Root system responses to the limitation of either nitrogen (N) or phosphorus (P) are well documented, but how the early root system responds to (co-) limitation of one (N or P) or both in a stoichiometric framework is not well-known. In addition, how intraspecific competition alters plant responses to N:P stoichiometry is understudied. Therefore, we aimed to investigate the effects of N:P stoichiometry and competition on root system responses and overall plant performance. Methods Plants (Hordeum vulgare L.) were grown in rhizoboxes for 24 days in the presence or absence of competition (three vs. one plant per rhizobox), and fertilized with different combinations of N:P (low N + low P, low N + high P, high N + low P, and high N + high P). Results Shoot biomass was highest when both N and P were provided in high amounts. In competition, shoot biomass decreased on average by 22%. Total root biomass (per plant) was not affected by N:P stoichiometry and competition but differences were observed in specific root length and root biomass allocation across soil depths. Specific root length depended on the identity of limiting nutrient (N or P) and competition. Plants had higher proportion of root biomass in deeper soil layers under N limitation, while a greater proportion of root biomass was found at the top soil layers under P limitation. Conclusions With low N and P availability during early growth, higher investments in root system development can significantly trade off with aboveground productivity, and strong intraspecific competition can further strengthen such effects.

scholarly journals Effect of parameter choice in root water uptake models – the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake

2014 ◽  
Vol 18 (10) ◽  
pp. 4189-4206 ◽  
Author(s):  
M. Bechmann ◽  
C. Schneider ◽  
A. Carminati ◽  
D. Vetterlein ◽  
S. Attinger ◽  
...  
Keyword(s):  
Root System ◽  
Water Uptake ◽  
Root Length ◽  
Hydraulic Properties ◽  
Three Dimensional ◽  
Root Systems ◽  
Root Water Uptake ◽  
Hydraulic Lift ◽  
Hydraulic Redistribution ◽  
Young Root

Abstract. Detailed three-dimensional models of root water uptake have become increasingly popular for investigating the process of root water uptake. However, they suffer from a lack of information on important parameters, particularly on the spatial distribution of root axial and radial conductivities, which vary greatly along a root system. In this paper we explore how the arrangement of those root hydraulic properties and branching within the root system affects modelled uptake dynamics, xylem water potential and the efficiency of root water uptake. We first apply a simple model to illustrate the mechanisms at the scale of single roots. By using two efficiency indices based on (i) the collar xylem potential ("effort") and (ii) the integral amount of unstressed root water uptake ("water yield"), we show that an optimal root length emerges, depending on the ratio between roots axial and radial conductivity. Young roots with high capacity for radial uptake are only efficient when they are short. Branching, in combination with mature transport roots, enables soil exploration and substantially increases active young root length at low collar potentials. Second, we investigate how this shapes uptake dynamics at the plant scale using a comprehensive three-dimensional root water uptake model. Plant-scale dynamics, such as the average uptake depth of entire root systems, were only minimally influenced by the hydraulic parameterization. However, other factors such as hydraulic redistribution, collar potential, internal redistribution patterns and instantaneous uptake depth depended strongly on the arrangement on the arrangement of root hydraulic properties. Root systems were most efficient when assembled of different root types, allowing for separation of root function in uptake (numerous short apical young roots) and transport (longer mature roots). Modelling results became similar when this heterogeneity was accounted for to some degree (i.e. if the root systems contained between 40 and 80% of young uptake roots). The average collar potential was cut to half and unstressed transpiration increased by up to 25% in composed root systems, compared to homogenous ones. Also, the least efficient root system (homogenous young root system) was characterized by excessive bleeding (hydraulic lift), which seemed to be an artifact of the parameterization. We conclude that heterogeneity of root hydraulic properties is a critical component for efficient root systems that needs to be accounted for in complex three-dimensional root water uptake models.

Characterization of soybean rooting depth in response to different environmental conditions

2020 ◽  
Author(s):  
◽  
Sulaiman Ahmed Ali
Keyword(s):  
Root System ◽  
Seed Yield ◽  
Soil Profile ◽  
Root Length ◽  
Root Traits ◽  
Root Systems ◽  
Field Conditions ◽  
Rooting Depth ◽  
Soybean Genotypes ◽  
Dry Down

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI-COLUMBIA AT REQUEST OF AUTHOR.] Soybean (Glycine max (L.) is currently grown throughout the world because it has been adapted to many environments and because of the high protein and oil content of the seeds. Water scarcity is responsible for the biggest crop losses worldwide and this is expected to worsen; thus, much attention is directed towards the development of drought tolerant crops. The root system is fundamentally important for plant growth and survival because of its role in water and nutrient uptake. Crops with deep roots can capture more soil resources, particularly water, to support shoot growth and yield formation. However, the investigation of root systems is difficult and remains challenging, especially under field conditions. Nonetheless, a better understanding of root system form and function is critical to develop strategies to breed for more stress-resilient crops for local production environments. Studies of soybean root systems in general, and rooting depth in particular have been limited. Thus, the aims of the research described in this dissertation were to (i) identify genotypic diversity in rooting depth and distribution of roots in the soil profile and relate these traits to above ground characteristics including yield under rainfed field conditions in a wide range of soybean genotypes, (ii) characterize, compare and contrast root systems of selected soybean genotypes grown under field- and greenhouse-conditions, and (iii) explore the influence of scion and rootstock genotype on root growth of contrasting soybean genotypes under well-watered and water deficit stress conditions. In the first series of experiments, a set of five soybean genotypes that represented contrasting root rooting depths and root elongation rates were selected based on greenhouse experiment and grown under rainfed field conditions. The core break method was used to assess root distributions of these genotypes in two years. The main goals of this experiment were to confirm genotypic variation for key root traits, including rooting depth and distribution, and to determine whether rooting depth is related to seed yield and selected shoot traits. This study confirmed significant variation among genotypes regarding their rooting depth and root distribution in the soil profile. Genotypes with greater maximum rooting depth also exhibited greater numbers of roots in the lower soil strata than shallower rooting genotypes, and rooting depth was positively correlated with seed yield. Confirmation of differences in rooting depth among these genotypes and the relationship with seed yield under field conditions establishes the suitability of the selected genotypes for physiological studies, studies of genetic mechanisms underpinning maximum rooting depth in soybean, and to confirm the potential for yield increase as a result of selection for deep rooting. A second study consisted of two greenhouse experiments to evaluate the effect of water availability on the rooting depth plasticity of deep- and shallow-rooted genotypes. Six contrasting genotypes were grown in PVC pipes under well-watered and dry-down conditions. The soil media was a mixture of soil and sand with a ratio of 4:1, respectively. Significant genotype, water treatment, and genotype by water treatment interaction effects were observed for maximum rooting depth. Maximum rooting depth increased in the dry-down compared to the well-watered treatment and induced a reallocation of root length from shallow strata to deeper regions in the profile for all genotypes. The extent of the difference in rooting depth between well-watered and dry-down treatments, measured as plasticity, was significantly different among genotypes. Thus, plasticity in maximum rooting depth appears to be under genetic control in soybean and may be a suitable target for breeding efforts aimed at increasing yields under drought. In a final study, the influence of scion and rootstock genotype on shoot growth and root system characteristics was examined in deep tubes in an automated rainout shelter. Plants were sown into 1.5- m deep tubes filled with a soil-sand mix (4:1) and grown under well-watered and dry-down conditions. Nine days after sowing, self and reciprocal grafts were made using the wedge grafting method. The dry-down treatment resulted in significantly increased rooting depth for all grafted as well as the non-grafted treatments compared to well-watered treatment. As expected, root length densities in the top 30 cm of the soil were greater for well-watered plants than plants in the dry-down treatment whereas the opposite was true for root length density at depth. Overall, whether self-grafted or serving as rootstock only, the deep-rooted genotype had a stimulatory effect on root growth in most soil strata, particularly under dry-down conditions. In general, limited differences observed among the grafting treatments suggest a small influence of the scion or rootstock genotype on the rooting depth and root distribution in the soil profile. However, grafting studies with additional genotypes should be conducted to explore whether this observation is specific to the genotype combination used in this study or whether it applies more generally for soybean. The experiments described in this dissertation lay the foundation for additional physiological and genetic studies. Further research is needed to ascertain the physiological mechanism behind the responses of contrasting genotypes, and to identify molecular markers and/or genes to facilitate incorporation of desirable root traits into a breeding program to increase yields and/or yield stability under drought conditions.

Distribution and density of the root system of macadamia on krasnozem soil and some effects of legume groundcovers on fibrous root density

2003 ◽  
Vol 43 (5) ◽  
pp. 503 ◽  
Author(s):  
D. J. Firth ◽  
R. D. B. Whalley ◽  
G. G. Johns
Keyword(s):  
Root System ◽  
Root Length ◽  
Root Length Density ◽  
Root Systems ◽  
Soil Cores ◽  
Fibrous Root ◽  
Proteoid Roots ◽  
Dry Conditions ◽  
Proteoid Root ◽  
Fibrous Roots

Whole-tree excavations, root-core and minirhizotron studies indicate that the grafted macadamia tree root system is relatively shallow and spreading, with a short taproot and most of the fibrous root system near the soil surface, while ungrafted trees have a longer taproot. The length of fibrous roots diminished with depth and distance from the trunk. This pattern is consistent with other fruit trees, in that the highest density is generally within 1 m of the trunk. Values obtained in core samples in this study were 4.97 (± 0.43) cm/cm3 and 1.67 (± 0.45) cm/cm3 for 0–10 cm and 10–20 cm at 0.5 m from the trunk, and 2.34 and 1.08 cm/cm3, respectively, at 1 m from the trunk at Clunes. These values were similar to those obtained in separate studies in 1991–93, involving assessments at 5�cm depth increments down to 15 cm, where mean root length densities were 2.0–3.5 cm/cm3 and 1.3–1.9 cm/cm3 at 0–5 cm and 5–15 cm depth, respectively, 1.4 m from the trunk. Root length under old trees in bare soil at Dorroughby and Clunes, using minirhizotrons (0.25–0.40 cm/cm2) and soil cores (1.14 and 3.50 cm/cm3, respectively), was similar to that found at other sites in the study area (minirhizotrons 0.28–0.33 cm/cm2; soil cores 1.25–2.80 cm/cm3). There is an apparent lower rate of decrease in root length density with increasing distance from the trunk at 10–20 cm compared with 0–10 cm. New root growth occurred predominantly in autumn, but some new fibrous roots were produced in early winter and spring. Proteoid roots were found in abundance in soil cores and adjacent to minirhizotron tubes and there were more of them in the root systems of younger trees at Clunes than with older trees at Dorroughby. Proteoid roots were found at a greater depth than previously recorded for other Proteaceae species, and appeared to retain their function in relatively dry conditions for more than a year. Non-proteoid fibrous roots at the minirhizotron surface appeared to be functional for about 1.5 years in relatively dry conditions, before decay after the onset of wet soil conditions.The effects of 2 newly established perennial legume groundcovers on the root systems of younger and older macadamia trees were studied over 2.5 years. In general, the presence of groundcover either had no effect on the growth of the macadamia roots or increased the root length density at some sampling dates and some depths. At Clunes, where the proteoid root length density was higher than at Dorroughby, the presence of groundcover was associated with higher proteoid root length density than that with bare ground. Arachis pintoi cv. Amarillo generally had a lower root length density than Lotus pedunculatus.

scholarly journals Differences in size and architecture of the potato cultivars root system and their tolerance to drought stress  

2017 ◽  
Vol 63 (No. 4) ◽  
pp. 159-164 ◽  
Author(s):  
Zarzyńska Krystyna ◽  
Boguszewska-Mańkowska Dominika ◽  
Nosalewicz Artur
Keyword(s):  
Drought Stress ◽  
Root System ◽  
Surface Area ◽  
Root Length ◽  
Tuber Yield ◽  
Root Systems ◽  
Potato Cultivars ◽  
Root Surface Area ◽  
Depth Range ◽  
Drought Conditions

Drought can cause substantial yield losses, particularly for crops with shallow root systems, such as potato (Solanum tuberosum). This study tested whether root system architecture could affect potato yield under drought conditions. The following parameters of the roots were measured: depth range, total length, total area, surface area, average diameter, and total dry weight of the root system. These parameters in soil layers were also measured at different depths. Five potato cultivars from a group of mid-early cultivars were examined in this study. The same cultivars were tested under two conditions: control with optimal irrigation and drought stress treatment without irrigation for three weeks after the end of tuberization to check the tuber yield. Significant differences were observed among cultivars in the size of the root system and its architecture. The biggest differences in the individual layers of soil profile related to the diameter of the root, the root length, and the surface area. Also a relationship between the size of the root system and yield of tubers was found. The strongest correlations involved the root length and the root surface area with the decrease in tuber yield under the drought, then the dry root mass with the decrease in yield. These correlations were negative: the higher the value of the parameter, the smaller the observed decrease in yield. This showed a relationship between root length and mass with the decrease of yield; this relationship was stronger for roots in deeper layers than in the shallowest layers. Therefore, this study indicates that breeding potato cultivars with deep root systems might improve tuber yields under drought conditions.

scholarly journals Propagation Techniques and Grafting Modify the Morphological Traits of Roots and Biomass Allocation in Avocado Trees

2016 ◽  
Vol 26 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Claudia Fassio ◽  
Ricardo Cautin ◽  
Alonso Pérez-Donoso ◽  
Claudia Bonomelli ◽  
Mónica Castro
Keyword(s):  
Root System ◽  
Biomass Allocation ◽  
Root Length ◽  
Morphological Traits ◽  
Root Length Density ◽  
Root Systems ◽  
Second Order ◽  
Total Length ◽  
Shoot Ratio ◽  
Root To Shoot Ratio

Root morphological traits and biomass allocation were studied in 2-year-old ‘Duke 7’ avocado (Persea americana) trees propagated using seedling and clonal techniques. The plants either were or were not grafted with the scion ‘Hass’. Whole tree excavation 1 year after planting revealed that the propagation technique affected the root growth angle of the main roots (third order roots), the root length density (defined as the total length of roots per volume of soil), and the number of first and second order roots present. The root system of clonal trees showed a typical morphology of rooted cuttings, with a crown of roots originating from a relatively short stem, resulting in a shallow root system. Clonal trees, compared with seedlings, produced main framework roots with shallower angles and more fine roots (first and second order roots) that increased the root length density (defined as the total length of roots per volume of soil). Nongrafted seedlings exhibited a main taproot and lateral roots with narrow angles that penetrated deeper into the soil and increased the aboveground biomass but had a lower root-to-shoot ratio than nongrafted clonal trees. The grafting of both clonal and seedling trees resulted in similar root architecture and revealed that grafting significantly decreased the soil volume explored and the shoot and root biomass. Although both root systems were shallow, grafted clonal trees had a higher root-to-shoot ratio than grafted seedlings. In this study, a distinct class of roots with large diameter and unbranched growth was more abundant in the root systems of clonal trees. These types of roots (previously undescribed in avocado trees), called pioneer roots, may enhance soil exploration in clonal trees.

scholarly journals Screening of Soybean Genotypes Based on Root Morphology and Shoot Traits Using the Semi-Hydroponic Phenotyping Platform and Rhizobox Technique

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 56
Author(s):  
Mohammad Salim ◽  
Yinglong Chen ◽  
Heng Ye ◽  
Henry T. Nguyen ◽  
Zakaria M. Solaiman ◽  
...  
Keyword(s):  
Root System ◽  
System Architecture ◽  
Root Length ◽  
Specific Root Length ◽  
Root Traits ◽  
Dry Weight ◽  
Root Systems ◽  
Root System Architecture ◽  
Flowering Stage ◽  
Soybean Genotypes

Root-system architecture is vital for improving soybean (Glycine max L.) growth and nutrient uptake. We characterised root-system architecture and shoot traits of 30 soybean genotypes in a semi-hydroponic system 35 days after sowing (DAS) and validated eight genotypes with contrasting root-system architecture in 1.5 m-deep rhizoboxes at the flowering stage. Among them, two genotypes were selected for evaluation through to maturity. Abundant variation (coefficient of variation values ≥ 0.25) was observed in 11 of 13 measured roots and shoot traits during the early growth stage. After late growth stages, strong positive correlations were found between root traits and shoot traits, except for specific root length and diameter. Seed yield and yield traits at final harvest significantly differed between two contrasting soybean genotypes. The large-rooted genotype had a higher harvest index than the small-rooted genotype. Soybean genotypes with larger root systems had a long time to flowering than those with smaller root systems. Genotypes with large-root systems had 106% more leaf area, and 245% more shoot dry weight than those with small systems, presumably due to high canopy photosynthesis to supply the demand for carbon assimilates to roots. Total root length, and root: shoot ratio-traits data collected in the rhizobox study, strongly correlated with the same traits in the semi-hydroponic phenotyping system. We found genetic variation and phenotypic plasticity in other root and shoot traits such as taproot depth, root dry weight, specific root length, and average root diameter among the tested genotypes. Phenology, particularly time to flowering, was associated with root system size. Some root and shoot traits in the semi-hydroponic phenotyping system at the seedling stage produced similar rankings at the later phenological (flowering) stage when grown in the soil-filled rhizoboxes. The soybean genotypes characterised by vastly different root traits could be used for further glasshouse and field studies to improve adaptation to drought and other specific environments.

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