scholarly journals Roots With Larger Specific Root Length and C: N Ratio Sustain More Complex Nematode Community

2021 ◽  
Author(s):  
Jingru Zhang ◽  
Zhengkun Hu ◽  
Chongzhe Zhang ◽  
Yiheng Tao ◽  
Xiaoyun Chen ◽  
...  
Keyword(s):  
Community Structure ◽  
Relative Abundance ◽  
Root Length ◽  
Root Length Density ◽  
Specific Root Length ◽  
Root Traits ◽  
Nematode Community ◽  
Soil Biodiversity ◽  
Root Area ◽  
Nematode Diversity

Abstract Aims Roots bridge above and belowground systems, and play a pivotal role in structuring root-associated organisms via influencing food resources and habitat conditions. Most studies focused on the relationships between plant identity and root-associated organisms, however, little is known about how root traits affect nematode communities within the rhizosphere. Methods We investigated the relationships between root traits of four plant species and nematode diversity, community structure and trophic complexity in an ex-arable field. Results While the relative abundance of herbivorous nematodes was negatively associated with specific root length (SRL), specific root area (SRA), root length density (RLD) and root C: N ratio, free-living nematodes were positively affected by these traits, implying a multifaceted effect of root traits on root-associated organisms. Importantly, we found that finer root systems promoted the complexity of the nematode community, by increasing the relative abundance of high trophic-level nematodes (i.e., omnivores and predators) and enhancing nematode diversity. Conclusion Our findings suggest that root traits could be reliable indicators of soil community structure and interactions, and provide new insights into soil biodiversity and functional maintenance.

scholarly journals Root Phenotyping for Drought Tolerance: A Review

Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 241 ◽  
Author(s):  
Allah Wasaya ◽  
Xiying Zhang ◽  
Qin Fang ◽  
Zongzheng Yan
Keyword(s):  
Drought Tolerance ◽  
Crop Yield ◽  
Root Length ◽  
Root Length Density ◽  
Canopy Temperature ◽  
Specific Root Length ◽  
Root Traits ◽  
Three Dimensions ◽  
Invasive Approach ◽  
Root Phenotyping

Plant roots play a significant role in plant growth by exploiting soil resources via the uptake of water and nutrients. Root traits such as fine root diameter, specific root length, specific root area, root angle, and root length density are considered useful traits for improving plant productivity under drought conditions. Therefore, understanding interactions between roots and their surrounding soil environment is important, which can be improved through root phenotyping. With the advancement in technologies, many tools have been developed for root phenotyping. Canopy temperature depression (CTD) has been considered a good technique for field phenotyping of crops under drought and is used to estimate crop yield as well as root traits in relation to drought tolerance. Both laboratory and field-based methods for phenotyping root traits have been developed including soil sampling, mini-rhizotron, rhizotrons, thermography and non-soil techniques. Recently, a non-invasive approach of X-ray computed tomography (CT) has provided a break-through to study the root architecture in three dimensions (3-D). This review summarizes methods for root phenotyping. On the basis of this review, it can be concluded that root traits are useful characters to be included in future breeding programs and for selecting better cultivars to increase crop yield under water-limited environments.

scholarly journals Drought Avoidance Traits in a Collection of Zoysiagrasses

HortScience ◽  
2018 ◽  
Vol 53 (11) ◽  
pp. 1579-1585 ◽  
Author(s):  
David Jespersen ◽  
Brian Schwartz
Keyword(s):  
Root Length ◽  
Root Biomass ◽  
Root Length Density ◽  
Warm Season ◽  
Specific Root Length ◽  
Root Traits ◽  
Plant Performance ◽  
Factors Affecting ◽  
Drought Avoidance ◽  
Turfgrass Quality

Drought avoidance is dictated by a collection of traits used to maintain tissue hydration levels and turgidity during water-limited conditions. These traits include deeper and more extensive rooting and the closure of stomata to limit the transpiration of water from leaves. Zoysiagrasses are a group of warm-season turfgrasses, including Zoysia japonica and Zoysia matrella, that are valued for their turfgrass quality; however, they are susceptible to drought relative to other warm-season turfgrass species. The objectives of the study were to determine 1) differences in drought avoidance among a collection of zoysiagrasses and 2) which drought avoidance traits contributed to these differences. Fifteen zoysiagrass genotypes were exposed to either drought or control conditions in a greenhouse environment. Overall performance was assessed by evaluating turfgrass quality and percentage green cover. Drought avoidance was estimated by measuring leaf hydration levels and drought avoidance traits [including stomatal conductance (gS)]; root traits such as total root biomass, specific root length (SRL), and root length density (RLD) were measured. Compared with commercial cultivars Meyer, Palisades, or Zeon, some experimental genotypes maintained greater turfgrass quality during drought, with experimental genotype ‘09-TZ-54-9’ having a quality rating of 7.8 after 20 days of drought compared with 5.3 in ‘Zeon’, 5.2 in ‘Meyer’, and 5.0 in ‘Palisades’. A range of belowground traits such as root biomass was also found to be associated with drought avoidance, with experimental ‘09-TZ-53-20’ having 1.03 total grams, and 2.39 total grams in ‘10-TZ-1254’, compared with 1.14, 1.66, and 3.44 total grams in ‘Meyer’, ‘Zeon’, and ‘Palisades’, respectively. Significant differences in drought avoidance were found among the 15 genotypes, with both belowground rooting traits and aboveground factors affecting transpiration influencing plant performance.

scholarly journals Effects of nitrogen addition on root traits and soil nitrogen in the long-term restored grasslands

2021 ◽  
Vol 67 (No. 9) ◽  
pp. 541-547
Author(s):  
Guanghua Jing ◽  
Zhikun Chen ◽  
Qiangqiang Lu ◽  
Liyan He ◽  
Ning Zhao ◽  
...  
Keyword(s):  
Root Length ◽  
Morphological Traits ◽  
Root Length Density ◽  
Microbial Biomass Carbon ◽  
Specific Root Length ◽  
Root Traits ◽  
N Deposition ◽  
Root Diameter ◽  
N Addition

Fine root traits are plastic and responsive to increased nitrogen (N) deposition. However, with the restoring of the ecosystem after grain for green, little research has been reported about the response of root traits in a long-term restored ecosystem to increased N deposition. Therefore, a successive N addition experiment was conducted in a long-term restored grassland on the Loess Plateau to analyse the effects of different N addition levels (0, 2.5, 5, 10, 20 g N/m<sup>2</sup>/year) on root morphological traits, soil carbon (C) and N. Our results showed that root morphological traits (except for root diameter) firstly increased and then declined, with the maximum in the N level of 5 g/m<sup>2</sup>/year. N addition significantly increased soil organic carbon, total nitrogen, ammonium nitrogen (NH<sub>4</sub><sup>+</sup>-N) and nitrate-nitrogen (NO<sub>3</sub><sup>–</sup>-N) with the increasing N addition level, especially in the soil surface layer. Specific root length and specific root area had remarkable negative correlations with NO<sub>3</sub><sup>–</sup>-N, while root diameter and root length density had positive correlations with soil availability N and soil microbial biomass carbon. This study indicated that plants could have the threshold response to adapt to the N addition and prefer to slowly grow rather than quickly invest and return in order to adapt to the environmental stress.  

Does a fungal species drive ectomycorrhizal root traits in Alnus spp.?

2009 ◽  
Vol 39 (10) ◽  
pp. 1787-1796 ◽  
Author(s):  
Ivika Ostonen ◽  
Leho Tedersoo ◽  
Triin Suvi ◽  
Krista Lõhmus
Keyword(s):  
Root Morphology ◽  
Root Length ◽  
Specific Root Length ◽  
Root Traits ◽  
Root Tip ◽  
Soil Parameters ◽  
Short Root ◽  
Root Area ◽  
Root Size ◽  
Specific Root Area

Ectomycorrhizal (EcM) fungi contribute significantly to the shaping of short-root morphology, playing an important role in balancing the costs and benefits of root growth and nutrient uptake and exchange in boreal forests. We aimed to assess the effect of various EcM fungal taxa on root traits at seven sites dominated by grey alder, Alnus incana (L.) Moench, and black alder, Alnus glutinosa (L.) Gaertn. Mean root size, specific root length, specific root area, root tissue density, and root-tip frequency of EcM short roots were measured in EcM anatomotypes in relation to the effects of host species, soil moisture level, and nutrient status. Redundancy analysis revealed that anatomotype, alder species, site, and soil parameters (N, P, K, Ca, and Mg concentrations, pH, organic-matter content) accounted for 42.3% (p < 0.001) of the total variation in EcM root morphology. Variation decreased in the following order: anatomotypes (27.9%) > soil parameters and sites (19.9%) > alder species (5.1%). EcM fungus species had the primary influence on EcM short-root size. EcM roots of the dominant anatomotype, Alnicola spp., had the highest specific root length and specific root area in both alder species. Short-root morphology depends most strongly on the fungal taxa involved, which indicates that the type of mycobiont has an important influence on the functional properties of fine roots.

Experimentally altered rainfall regimes and host root traits affect grassland arbuscular mycorrhizal fungal communities

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Suzanne Donn ◽  
Sally Power ◽  
Kirk Barnett ◽  
Jeff Powell
Keyword(s):  
Fungal Community ◽  
Community Assembly ◽  
Root Length ◽  
Specific Root Length ◽  
Root Traits ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Rainfall Regime ◽  
Precipitation Regimes ◽  
Rainfall Regimes

Future climate scenarios predict changes in rainfall regimes. These changes are expected to affect plants via effects on the expression of root traits associated with water and nutrient uptake. Associated microorganisms may also respond to these new precipitation regimes, either directly in response to changes in the soil environment or indirectly in response to altered root trait expression. We characterised arbuscular mycorrhizal (AM) fungal communities in an Australian grassland exposed to experimentally altered rainfall regimes. We used Illumina sequencing to assess the responses of AM fungal communities associated with four plant species sampled in different watering treatments and evaluated the extent to which shifts were associated with changes in root traits. We observed that altered rainfall regimes affected the composition but not the richness of the AM fungal communities, and we found distinctive communities in the increased rainfall treatment. We found no evidence of altered rainfall regime effects via changes in host physiology because none of the studied traits were affected by changes in rainfall. However, specific root length was observed to correlate with AM fungal richness, while concentrations of phosphorus and calcium in root tissue and the proportion of root length allocated to fine roots were correlated to community composition. Our study provides evidence that climate change and its effects on rainfall may influence AM fungal community assembly, as do plant traits related to plant nutrition and water uptake. We did not find evidence that host responses to altered rainfall drive AM fungal community assembly in this grassland ecosystem.

Sex-specifically responsive strategies to phosphorus availability combined with different soil nitrogen forms in dioecious Populus cathayana

2021 ◽  
Author(s):  
Xiucheng Liu ◽  
Yuting Wang ◽  
Shuangri Liu ◽  
Miao Liu
Keyword(s):  
Root Length ◽  
Root Length Density ◽  
Specific Root Length ◽  
P Uptake ◽  
Root Tip ◽  
P Availability ◽  
P Deficiency ◽  
Populus Cathayana ◽  
Leaf P ◽  
P Supply

Abstract Aims Phosphorus (P) availability and efficiency are especially important for plant growth and productivity. However, the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear. Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency, nitrate (NO3 −) and ammonium (NH4 +) supply. Important Findings Females had a greater biomass, root length density (RLD), specific root length (SRL) and shoot P concentration than males under normal P availability with two N supplies. NH4 + supply led to higher total root length, RLD and SRL but lower root tip number than NO3 − supply under normal P supply. Under P deficiency, males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization, exhibiting a better capacity to adaptation to P-deficiency than females. Under P deficiency, NO3 − supply increased leaf photosynthesis and PUE but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4 + supply. Females had a better potentiality to cope with P deficiency under NO3 − supply than NH4 + supply; the contrary was true for males. These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability, especially under NO3 − supply, while males adopt more efficient resource use and P remobilization to maximum their tolerance to P-deficiency.

scholarly journals Variability of root traits in common bean genotypes at different levels of phosphorus supply and ontogenetic stages

2014 ◽  
Vol 38 (4) ◽  
pp. 1170-1180 ◽  
Author(s):  
Roberto dos Santos Trindade ◽  
Adelson Paulo Araújo
Keyword(s):  
Common Bean ◽  
Root Length ◽  
Root Traits ◽  
Growth Stages ◽  
Phenotypic Variance ◽  
Root Mass ◽  
Root Area ◽  
Ontogenetic Stages ◽  
Growth Habits ◽  
Selection Of

Selection of common bean (Phaseolus vulgaris L.) cultivars with enhanced root growth would be a strategy for increasing P uptake and grain yield in tropical soils, but the strong plasticity of root traits may compromise their inclusion in breeding programs. The aim of this study was to evaluate the magnitude of the genotypic variability of root traits in common bean plants at two ontogenetic stages and two soil P levels. Twenty-four common bean genotypes, comprising the four growth habits that exist in the species and two wild genotypes, were grown in 4 kg pots at two levels of applied P (20 and 80 mg kg-1) and harvested at the stages of pod setting and early pod filling. Root area and root length were measured by digital image analysis. Significant genotype × P level and genotype × harvest interactions in analysis of variance indicate that the genotypic variation of root traits depended on soil nutrient availability and the stage at which evaluation was made. Genotypes differed for taproot mass, basal and lateral root mass, root area and root length at both P levels and growth stages; differences in specific root area and length were small. Genotypes with growth habits II (upright indeterminate) and III (prostrate indeterminate) showed better adaptation to limited P supply than genotypes of groups I (determinate) and IV (indeterminate climbing). Between the two harvests, genotypes of groups II and III increased the mass of basal and lateral roots by 40 and 50 %, respectively, whereas genotypes of groups I and IV by only 7 and 19 %. Values of the genotypic coefficient of determination, which estimates the proportion of phenotypic variance resulting from genetic effects, were higher at early pod filling than at pod setting. Correlations between shoot mass and root mass, which could indicate indirect selection of root systems via aboveground biomass, were higher at early pod filling than at pod setting. The results indicate that selection for root traits in common bean genotypes should preferentially be performed at the early pod-filling stage.

scholarly journals Novel approaches to improving growth of pasture legumes at low phosphorus levels

2014 ◽  
Vol 76 ◽  
pp. 197-202
Author(s):  
S.N. Nichols ◽  
J.R. Crush
Keyword(s):  
White Clover ◽  
Root Length ◽  
Specific Root Length ◽  
Root Traits ◽  
Dry Weight ◽  
Root Weight ◽  
Soil P ◽  
P Acquisition ◽  
Shoot Dry Weight ◽  
Use Efficiency

Abstract Strategies to reduce the economic and environmental costs of phosphate (P) fertiliser use in mixed pastures through plant breeding are focussed on inefficiencies in the legume component. One approach is breeding within white clover for root systems with improved P acquisition properties. Selection for root length per unit root weight (specific root length, SRL) showed that higher SRL plants could retain more biomass in the above ground fraction with decreasing soil P, whereas plants with lower SRL diverted more biomass to roots. Back cross 1 (BC1) generation interspecific hybrids between white clover and a wild relative, Trifolium uniflorum L., may possess additional root traits influencing P acquisition. In glasshouse experiments, some T. repens × T. uniflorum hybrids, back-crossed to white clover, also exhibited higher shoot dry weight than their white clover cultivar parents at low nutrient supply levels and low to intermediate soil Olsen P. This, combined with low internal P concentrations, suggests some BC1 hybrids may be more tolerant of low soil P than white clover. Differences in both P acquisition ability and internal P use efficiency may contribute to the observed yield differences. There are good prospects for delivery of new-generation clover cultivars with improved phosphate use efficiency to New Zealand farmers. Keywords: phosphorus, white clover, Trifolium uniflorum, interspecific

scholarly journals ROOT GROWTH OF CHINESE JUNIPER DURING THE FIRST THREE YEARS AFTER PLANTING

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1064e-1064 ◽  
Author(s):  
Edward F. Gilman ◽  
Michael E. Kane
Keyword(s):  
Root Growth ◽  
Root System ◽  
Root Length ◽  
Root Length Density ◽  
Root Diameter ◽  
Root Weight ◽  
Root Area ◽  
Black Plastic ◽  
Shoot Weight ◽  
Root Spread

Shoot and root growth were measured on Chinese juniper (Juniperus chinensis L.) Var. `Torulosa', `Sylvestris', `Pfitzeriana' and `Hetzii' 1, 2 and 3 years after planting into a simulated landscape from 10-liter black plastic containers. Mean diameter of the root system increased quadratically averaging 1, 2 m/year; whereas, mean branch spread increased at 0, 33 m/year, Three years after planting, root spread was 2, 75 times branch spread and roots covered an area 5.5 times that covered by the branches. Percentage of total root length located within the dripline of the plants remained fairly constant (71-77%) during the first 3 years following planting. Root length density per unit area increased over time but decreased with distance from the trunk. In the first 2 years after planting shoot weight increased faster than root `weight. However, during the third year after planting, the root system increased in mass and size at a faster rate than the shoots. Root length was correlated with root weight within root-diameter classes, Root spread and root area were correlated with trunk area, branch spread and crown area.

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