Plastic response of Medicago sativa L. root system traits and cold resistance to simulated rainfall events

Climate change (rainfall events and global warming) affects the survival of alfalfa (Medicago sativa L.) in winter. Appropriate water management can quickly reduce the mortality of alfalfa during winter. To determine how changes in water affect the cold resistance of alfalfa, we explored the root system traits under different rainfall events and the effects on cold resistance in three alfalfa cultivars. These were exposed to three simulated rainfall events (SRE) × two phases in a randomized complete block design with six replications. The three cultivars were WL168, WL353 and WL440, and the three SRE were irrigation once every second day (D2), every four days (D4) and every eight days (D8). There were two phases: before cold acclimation and after cold acclimation. Our results demonstrated that a period of exposure to low temperature was required for alfalfa to achieve maximum cold resistance. The root system tended toward herringbone branching under D8, compared with D2 and D4, and demonstrated greater root biomass, crown diameter, root volume, average link length and topological index. Nevertheless, D8 had less lateral root length, root surface area, specific root length, root forks and fractal dimensions. Greater root biomass and topological index were beneficial to cold resistance in alfalfa, while more lateral roots and root forks inhibited its ability to survive winter. Alfalfa roots had higher proline, soluble sugar and starch content in D8 than in D2 and D4. In contrast, there was lower malondialdehyde in D8, indicating that alfalfa had better cold resistance following a longer irrigation interval before winter. After examining root biomass, root system traits and physiological indexes we concluded that WL168 exhibited stronger cold resistance. Our results contribute to greater understanding of root and cold stress, consequently providing references for selection of cultivars and field water management to improve cold resistance of alfalfa in the context of changes in rainfall patterns.

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

Plant and Soil ◽

10.1007/s11104-020-04626-w ◽

2020 ◽

Vol 453 (1-2) ◽

pp. 515-528 ◽

Cited By ~ 1

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.

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A Meta-Analysis of Modifications of Root System Traits of Crop Plants to Potassium (K) Deprivation

10.5772/intechopen.95044 ◽

2020 ◽

Author(s):

David Oscar Yawson ◽

Kwadwo Kusi Amoah ◽

Paul Agu Asare ◽

Josiah Techie-Menson ◽

Emmanuel Afutu ◽

...

Keyword(s):

Root System ◽

Root Length ◽

Root Biomass ◽

Cropping Systems ◽

Meta Analysis ◽

Cumulative Effect ◽

Tissue Level ◽

Crop Plants ◽

Growth Media ◽

K Fertilizer

Unlike nitrogen (N) and phosphorus (P), morphological responses of root systems of crop plants to potassium (K) dynamics in soils or growth media are only gaining currency. This is due to the realization of the instrumental role of K in several cellular and tissue level processes crucial for the growth, stress tolerance, metabolic functions, and yield of crop plants, and ultimately, food security and sustainable agriculture. This chapter used meta-analysis to synthesize the pooled evidence for modifications in several root system traits of different crop plants under conditions of K starvation in different growth media. In all, 37 studies that passed inclusion/exclusion criteria, from 1969 to 2019, were analyzed in aggregate and then disaggregated for root biomass, root length, and the number of roots. Three moderators were analyzed: type of soil or growth medium, crop, and K fertilizer applied in the included studies. The aggregated results show that the cumulative effect of K deprivation was a significant and large reduction (about 25.5 ± 15.0%) in the bulk of root system traits considered, which was slightly lower than the reduction in shoot- or yield-related traits. Reductions of approximately 38 ± 38.0% in root biomass and 23.2 ± 18.6% in root length were observed, and the magnitudes of reduction were comparable to those observed from the disaggregated data. Though reductions in root system traits due to K starvation occurred under both greenhouse/lab and field conditions, the cumulative reduction in the former was significantly larger than that of the latter. Among the moderators, the effect of type of soil (or growth media) and crop on the scale of modification of root system traits to K deprivation are stronger compared to the effect of type of K fertilizer applied. It is concluded that, overall, K deprivation leads to significant reductions in root system traits, especially root biomass and length in soils and perlite regardless of the type of K fertilizer applied. Attention should be given to K management in cropping systems to avoid K starvation, especially at the early and vegetative stages, and to improve K reserves in soils. Further attention should be given to the responses of root system traits to K supply when matching crops to soils.

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Effect of earthworms on mycorrhization, root morphology and biomass of silver fir seedlings inoculated with black summer truffle (Tuber aestivum Vittad.)

Scientific Reports ◽

10.1038/s41598-021-85497-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tina Unuk Nahberger ◽

Gian Maria Niccolò Benucci ◽

Hojka Kraigher ◽

Tine Grebenc

Keyword(s):

Root System ◽

Root Biomass ◽

Fine Root ◽

Abies Alba ◽

Fine Root Biomass ◽

Root Tip ◽

Silver Fir ◽

Tuber Aestivum ◽

Root Tips ◽

Root Parameters

AbstractSpecies of the genus Tuber have gained a lot of attention in recent decades due to their aromatic hypogenous fruitbodies, which can bring high prices on the market. The tendency in truffle production is to infect oak, hazel, beech, etc. in greenhouse conditions. We aimed to show whether silver fir (Abies alba Mill.) can be an appropriate host partner for commercial mycorrhization with truffles, and how earthworms in the inoculation substrate would affect the mycorrhization dynamics. Silver fir seedlings inoculated with Tuber. aestivum were analyzed for root system parameters and mycorrhization, how earthworms affect the bare root system, and if mycorrhization parameters change when earthworms are added to the inoculation substrate. Seedlings were analyzed 6 and 12 months after spore inoculation. Mycorrhization with or without earthworms revealed contrasting effects on fine root biomass and morphology of silver fir seedlings. Only a few of the assessed fine root parameters showed statistically significant response, namely higher fine root biomass and fine root tip density in inoculated seedlings without earthworms 6 months after inoculation, lower fine root tip density when earthworms were added, the specific root tip density increased in inoculated seedlings without earthworms 12 months after inoculation, and general negative effect of earthworm on branching density. Silver fir was confirmed as a suitable host partner for commercial mycorrhization with truffles, with 6% and 35% mycorrhization 6 months after inoculation and between 36% and 55% mycorrhization 12 months after inoculation. The effect of earthworms on mycorrhization of silver fir with Tuber aestivum was positive only after 6 months of mycorrhization, while this effect disappeared and turned insignificantly negative after 12 months due to the secondary effect of grazing on ectomycorrhizal root tips.

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Genome-wide association analysis unveils novel QTLs for seminal root system architecture traits in Ethiopian durum wheat

BMC Genomics ◽

10.1186/s12864-020-07320-4 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Admas Alemu ◽

Tileye Feyissa ◽

Marco Maccaferri ◽

Giuseppe Sciara ◽

Roberto Tuberosa ◽

...

Keyword(s):

Durum Wheat ◽

Root System ◽

System Architecture ◽

Root Length ◽

Dry Weight ◽

Root System Architecture ◽

High Density ◽

Soil Conditions ◽

Root Dry Weight ◽

Seminal Roots

Abstract Background Genetic improvement of root system architecture is essential to improve water and nutrient use efficiency of crops or to boost their productivity under stress or non-optimal soil conditions. One hundred ninety-two Ethiopian durum wheat accessions comprising 167 historical landraces and 25 modern cultivars were assembled for GWAS analysis to identify QTLs for root system architecture (RSA) traits and genotyped with a high-density 90 K wheat SNP array by Illumina. Results Using a non-roll, paper-based root phenotyping platform, a total of 2880 seedlings and 14,947 seminal roots were measured at the three-leaf stage to collect data for total root length (TRL), total root number (TRN), root growth angle (RGA), average root length (ARL), bulk root dry weight (RDW), individual root dry weight (IRW), bulk shoot dry weight (SDW), presence of six seminal roots per seedling (RT6) and root shoot ratio (RSR). Analysis of variance revealed highly significant differences between accessions for all RSA traits. Four major (− log10P ≥ 4) and 34 nominal (− log10P ≥ 3) QTLs were identified and grouped in 16 RSA QTL clusters across chromosomes. A higher number of significant RSA QTL were identified on chromosome 4B particularly for root vigor traits (root length, number and/or weight). Conclusions After projecting the identified QTLs on to a high-density tetraploid consensus map along with previously reported RSA QTL in both durum and bread wheat, fourteen nominal QTLs were found to be novel and could potentially be used to tailor RSA in elite lines. The major RGA QTLs on chromosome 6AL detected in the current study and reported in previous studies is a good candidate for cloning the causative underlining sequence and identifying the beneficial haplotypes able to positively affect yield under water- or nutrient-limited conditions.

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Shoot and Root Traits Underlying Genotypic Variation in Early Vigor and Nutrient Accumulation in Spring Wheat Grown in High-Latitude Light Conditions

Plants ◽

10.3390/plants10010174 ◽

2021 ◽

Vol 10 (1) ◽

pp. 174

Author(s):

Hui Liu ◽

Fabio Fiorani ◽

Ortrud Jäck ◽

Tino Colombi ◽

Kerstin A. Nagel ◽

...

Keyword(s):

Root System ◽

Leaf Area ◽

Spring Wheat ◽

High Latitude ◽

Root Length ◽

Nutrient Use Efficiency ◽

Root Traits ◽

Plant Production ◽

Nutrient Accumulation ◽

Early Vigor

Plants with improved nutrient use efficiency are needed to maintain and enhance future crop plant production. The aim of this study was to explore candidate traits for pre-breeding to improve nutrient accumulation and early vigor of spring wheat grown at high latitudes. We quantified shoot and root traits together with nutrient accumulation in nine contrasting spring wheat genotypes grown in rhizoboxes for 20 days in a greenhouse. Whole-plant relative growth rate was here correlated with leaf area productivity and plant nitrogen productivity, but not leaf area ratio. Furthermore, the total leaf area was correlated with the accumulation of six macronutrients, and could be suggested as a candidate trait for the pre-breeding towards improved nutrient accumulation and early vigor in wheat to be grown in high-latitude environments. Depending on the nutrient of interest, different root system traits were identified as relevant for their accumulation. Accumulation of nitrogen, potassium, sulfur and calcium was correlated with lateral root length, whilst accumulation of phosphorus and magnesium was correlated with main root length. Therefore, special attention needs to be paid to specific root system traits in the breeding of wheat towards improved nutrient accumulation to counteract the suboptimal uptake of some nutrient elements.

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EFFECTS OF ALUMINIUM ON THE ADVENTITIOUS ROOT SYSTEM, AERIAL BIOMASS AND GRAIN YIELD OF MAIZE GROWN IN THE FIELD AND IN A RHIZOTRON

Experimental Agriculture ◽

10.1017/s0014479706003620 ◽

2006 ◽

Vol 42 (3) ◽

pp. 351-366 ◽

Cited By ~ 4

Author(s):

J. J. COMIN ◽

J. BARLOY ◽

V. HALLAIRE ◽

F. ZANETTE ◽

P. R. M. MILLER

Keyword(s):

Grain Yield ◽

Root System ◽

Soil Solution ◽

Root Length ◽

Adventitious Root ◽

Adventitious Roots ◽

Total Root Length ◽

Al Tolerance ◽

Root Branching ◽

Four Levels

The aim of this work was to study the effects of soluble aluminium on the morphology and growth of the adventitious root system, aerial biomass and grain yield of maize (Zea mays). The analysis focuses on two hybrid cultivars (Al-sensitive HS7777 and Al-tolerant C525M). Experiments were carried out in the field and in a rhizotron in Curitiba, Paraná, Brazil. In the field, four levels of lime application were used: T0 = 0 t ha−1, T1 = 3.5 t ha−1, T2 = 7.0 t ha−1, and T3 = 10.5 t ha−1. Two levels were used in a rhizotron: T0 and T3. In the surface horizon (0–15 cm), the Al concentrations of the soil solution were: T0 = 15, T1 = 5.1, T2 = 4.4, and T3 = 3.1 μM. In the field, neither Al concentration in the soil solution nor cultivar affected the number of primary adventitious roots per internode or the total number of primary adventitious roots. However, root diameter, plant population and grain yield of the two cultivars confirmed the differences in Al tolerance between them. Al was observed to have an adverse effect on the grain yield from C525M, while low yields from HS7777, at all levels of Al, precluded any response to liming. In the rhizotron studies, Al concentration and cultivar affected the root branching and total root length. Cultivar C525M had more branches and total root length than HS7777, mainly at low concentrations of soil Al solution, leading to greater spatial colonization of the soil down to 0.9 m depth.

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Biomass allocation in tomato (Lycopersicon esculentum) plants grown under partial rootzone drying: enhancement of root growth

Functional Plant Biology ◽

10.1071/fp04020 ◽

2004 ◽

Vol 31 (10) ◽

pp. 971 ◽

Cited By ~ 84

Author(s):

Darren M. Mingo ◽

Julian C. Theobald ◽

Mark A. Bacon ◽

William J. Davies ◽

Ian C. Dodd

Keyword(s):

Lycopersicon Esculentum ◽

Root System ◽

Biomass Allocation ◽

Root Biomass ◽

Leaf Water ◽

Total Biomass ◽

Split Root ◽

Split Root System ◽

Partial Rootzone Drying ◽

And Control

Tomato (Lycopersicon esculentum Mill.) plants were grown in either a glasshouse (GH) or a controlled environment cabinet (CEC) to assess the effects of partial rootzone drying (PRD) on biomass allocation. Control and PRD plants received the same amounts of water. In control plants, water was equally distributed between two compartments of a split-root system. In PRD plants, only one compartment was watered while the other was allowed to dry. At the end of each drying cycle, wet and dry compartments were alternated. In the GH, total biomass did not differ between PRD and control plants after four cycles of PRD, but PRD increased root biomass by 55% as resources were partitioned away from shoot organs. In the CEC, leaf water potential did not differ between treatments at the end of either of two cycles of PRD, but stomatal conductance of PRD plants was 20% less at the end of the first cycle than at the beginning. After two cycles of PRD in the CEC, biomass did not differ between PRD and control plants, but PRD increased root biomass by 19% over the control plants. The promotion of root biomass in PRD plants was associated with the alternation of wet and dry compartments, with increased root biomass occurring in the re-watered compartment after previous exposure to soil drying. Promotion of root biomass in field-grown PRD plants may allow the root system to access resources (water and nutrients) that would otherwise be unavailable to control plants. This may contribute to the ability of PRD plants to maintain similar leaf water potentials to conventionally irrigated plants, even when smaller irrigation volumes are supplied.

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Root production, mortality and turnover in soil profiles as affected by clipping in a temperate grassland on the Loess Plateau

Journal of Plant Ecology ◽

10.1093/jpe/rtz039 ◽

2019 ◽

Vol 12 (6) ◽

pp. 1059-1072

Author(s):

Lin Wei ◽

Pengwei Yao ◽

Guanghua Jing ◽

Xiefeng Ye ◽

Jimin Cheng

Keyword(s):

Loess Plateau ◽

Soil Profile ◽

Root Length ◽

Root Biomass ◽

Turnover Rate ◽

Fine Root ◽

Root Production ◽

The Loess Plateau ◽

Soil Layers ◽

Root Mortality

Abstract Aims Clipping or mowing for hay, as a prevalent land-use practice, is considered to be an important component of global change. Root production and turnover in response to clipping have great implications for the plant survival strategy and grassland ecosystem carbon processes. However, our knowledge about the clipping effect on root dynamics is mainly based on root living biomass, and limited by the lack of spatial and temporal observations. The study aim was to investigate the effect of clipping on seasonal variations in root length production and mortality and their distribution patterns in different soil layers in semiarid grassland on the Loess Plateau. Methods Clipping was performed once a year in June to mimic the local spring livestock grazing beginning from 2014. The minirhizotron technique was used to monitor the root production, mortality and turnover rate at various soil depths (0–10, 10–20, 20–30 and 30–50 cm) in 2014 (from 30 May to 29 October) and 2015 (from 22 April to 25 October). Soil temperature and moisture in different soil layers were also measured during the study period. Important Findings Our results showed that: (i) Clipping significantly decreased the cumulative root production (P < 0.05) and increased the cumulative root mortality and turnover rates of the 0–50 cm soil profile for both years. (ii) Clipping induced an immediate and sharp decrease in root length production and an increase in root length mortality in all soil layers. However, with plant regrowth, root production increased and root mortality decreased gradually, with the root production at a depth of 30–50 cm even exceeding the control in September–October 2014 and April–May 2015. (iii) Clipping mainly reduced root length production and increased root length mortality in the upper 0–20 cm soil profile with rapid root turnover. However, roots at deeper soil layers were either little influenced by clipping or exhibited an opposite trend with slower turnover rate compared with the upper soil profile, leading to the downward transport of root production and living root biomass. These findings indicate that roots in deeper soil layers tend to favour higher root biomass and longer fine root life spans to maximize the water absorption efficiency under environmental stress, and also suggest that short-term clipping would reduce the amount of carbon through fine root litter into the soil, especially in the shallow soil profile.

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Effects of warming and fertilization interacting with intraspecific competition on fine root traits of Picea asperata

Journal of Plant Ecology ◽

10.1093/jpe/rtaa074 ◽

2020 ◽

Author(s):

Dan-Dan Li ◽

Hong-Wei Nan ◽

Chun-Zhang Zhao ◽

Chun-Ying Yin ◽

Qing Liu

Keyword(s):

Root Growth ◽

Climate Warming ◽

Tree Growth ◽

Root Length ◽

Root Biomass ◽

Fine Root ◽

Root Traits ◽

Root Surface ◽

Root Branching ◽

Picea Asperata

Abstract Aims Competition, temperature, and nutrient are the most important determinants of tree growth in the cold climate on the eastern Tibetan Plateau. Although many studies have reported their individual effects on tree growth, little is known about how the interactions of competition with fertilization and temperature affect root growth. We aim to test whether climate warming and fertilization promote competition and to explore the functional strategies of Picea asperata in response to the interactions of these factors. Methods We conducted a paired experiment including competition and non-competition treatments under elevated temperature (ET) and fertilization. We measured root traits, including the root tip number over the root surface (RTRS), the root branching events over the root surface (RBRS), the specific root length (SRL), the specific root area (SRA), the total fine root length and area (RL and RA), the root tips (RT) and root branching events (RB). These root traits are considered to be indicators of plant resource uptake capacity and root growth. The root biomass and the nutrient concentrations in the roots were also determined. Important Findings The results indicated that ET, fertilization and competition individually enhanced the nitrogen (N) and potassium (K) concentrations in fine roots, but they did not affect fine root biomass or root traits, including RL, RT, RA and RB. However, both temperature and fertilization, as well as their interaction, interacting with competition increased RL, RA, RT, RB, and nutrient uptake. In addition, the SRL, SRA, RTRS and RBRS decreased under fertilization, the interaction between temperature and competition decreased SRL and SRA, while the other parameters were not affected by temperature or competition. These results indicate that Picea asperata maintains a conservative nutrient strategy in response to competition, climate warming, fertilization, and their interactions. Our results improve our understanding of the physiological and ecological adaptability of trees to global change.

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Effect of nitrogen on the distribution of biomass and element composition of the root system of miscanthus × giganteus

Archives of Biological Sciences ◽

10.2298/abs141010017d ◽

2015 ◽

Vol 67 (2) ◽

pp. 547-560 ◽

Cited By ~ 2

Author(s):

Zeljko Dzeletovic ◽

Djordje Glamoclija

Keyword(s):

Root System ◽

Aboveground Biomass ◽

Root Biomass ◽

N Fertilization ◽

Element Composition ◽

Simple Experiment ◽

Miscanthus Giganteus ◽

Dry Biomass ◽

Macro And Micronutrients ◽

Mn Concentrations

Perennial bioenergy grass crops, despite a relatively similar production of aboveground biomass, show significant differences in the overall root biomass. Rhizomes play a key role in economizing nutrients in miscanthus. The aim of this research was to establish the effect of N (nitrogen) on the distribution of biomass and concentration of major macro- and micronutrients in the miscanthus root system, using simple experiment in pots. After two years of growth, the rhizomes and roots were taken out of the pots, cleaned of earth and analyzed. About 2/3 of the mass of the miscanthus root system consist of rhizome mass. The overall dry biomass of newly formed rhizomes and roots is decreased with the increase in the amount of applied N fertilization. Thereby, the N concentration in the entire root system, as well as in some of its parts, increased with the rise in applied amount of N. Our results show that increasing amounts of applied N consistently negatively correlate with P concentrations in the miscanthus root system, in contrast to Mn concentrations, with which they correlate positively.

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