Covariation in root traits of Leymus chinensis in response to grazing in steppe rangeland

2019 ◽  
Vol 41 (4) ◽  
pp. 313
Author(s):  
Wei Xiaoting ◽  
Zhong Mengying ◽  
Liu Yuehua ◽  
Wu Ruixin ◽  
Shao Xinqing
Keyword(s):  
Root Length ◽  
Topological Structure ◽  
Grazing Intensity ◽  
Root Traits ◽  
Root Surface ◽  
Leymus Chinensis ◽  
Root Surface Area ◽  
Total Root Length ◽  
Grazing Season ◽  
Heavy Grazing

Root traits are closely related to nutrient absorption and resource competition and can even influence plant recovery and community succession. Grazing can influence root traits directly through trampling and foraging, or indirectly by changing soil characteristics. In the present study, a grazing experiment that involved combinations of grazing season (from June to September) and intensity (rest, moderate and heavy) was conducted in steppe rangeland, Inner Mongolia, China to investigate how the root traits of Leymus chinensis respond to different grazing regimes in the case of aboveground miniaturisation after long-term overgrazing. Root traits such as root length, root surface area, specific root length, root tissue density, root links (unbranched parts of a root connecting either a tip and a branching point or two branching points) and root topological structure were scanned and analysed using Win-RHIZO image analysis software. The results showed that the size of L. chinensis plants was reduced in response to overgrazing, typically by a smaller plant height, total root length, root surface area, root volume, number of tips and number of links. However, root diameter and link length, branching angle and topological structure (herringbone or dichotomous) were unaffected by grazing. Most root traits showed strong correlations under moderate grazing intensity, but not under heavy grazing, indicating that grazing changed the relationships among root traits. Relationships between plant height and root traits (total root length and number of links) shifted from positive to negative as grazing intensity increased, and the trade-off between aboveground and belowground traits was an important adaptive strategy of L. chinensis under heavy grazing. Decreasing grazing intensity in the late grazing season could benefit plant recovery, and a rest in the early grazing season would mitigate root and shoot damage.

scholarly journals Phenotypic Diversity for Root Traits and Identification of Superior Germplasm for Root Breeding in Watermelon

HortScience ◽  
2020 ◽  
Vol 55 (8) ◽  
pp. 1272-1279
Author(s):  
Dennis N. Katuuramu ◽  
W. Patrick Wechter ◽  
Marcellus L. Washington ◽  
Matthew Horry ◽  
Matthew A. Cutulle ◽  
...  
Keyword(s):  
Root System ◽  
Surface Area ◽  
Root Length ◽  
Root Traits ◽  
Root Surface ◽  
Root Diameter ◽  
Root Surface Area ◽  
Total Root Length ◽  
Root Volume ◽  
Diverse Range

Root traits are an important component for productive plant performance. Roots offer immediate absorptive surfaces for water and nutrient acquisition and are thus critical to crop growth and response to biotic and abiotic stresses. In addition, roots can provide the first line of defense against soilborne pathogens. Watermelon crop performance is often challenged by inclement weather and environmental factors. A resilient root system can support the watermelon crop’s performance across a diverse range of production conditions. In this study, 335 four-day-old watermelon (Citrullus spp.) seedlings were evaluated for total root length, average root diameter, total root surface area, and total root volume. Total root length varied from 8.78 to 181 cm (20.6-fold variation), total surface area varied from 2 to 35.5 cm2, and average root diameter and total root volume had an 8- and 29.5-fold variation, respectively. Genotypes PI 195927 (Citrullus colocynthis) and PI 674448 (Citrullus amarus) had the largest total root length values. Accessions PI 674448 and PI 494817 (C. amarus) had the largest total root surface area means. Watermelon cultivars (Citrullus lanatus) had a relatively smaller root system and significantly fewer fibrous roots when compared with the roots of the other Citrullus spp. Positive genetic correlations were identified among total root length, total root surface area, and total root volume. This genetic information will be useful in future breeding efforts to select for multiple root architecture traits in watermelon. Germplasm identified in this study that exhibit superior root traits can be used as parental choices to improve watermelon for root traits.

scholarly journals Integrating GWAS and Gene Expression Analysis Identifies Candidate Genes for Root Morphology Traits in Maize at the Seedling Stage

Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 773 ◽  
Author(s):  
Wang ◽  
Wei ◽  
Li ◽  
Wang ◽  
Ge ◽  
...  
Keyword(s):  
Root System ◽  
Candidate Genes ◽  
Root Development ◽  
Root Length ◽  
Root Traits ◽  
Root Surface ◽  
Root Surface Area ◽  
Phenotypic Variance ◽  
Potential Candidate ◽  
Short Root

Root system plays an essential role in water and nutrient acquisition in plants. Understanding the genetic basis of root development will be beneficial for breeding new cultivars with efficient root system to enhance resource use efficiency in maize. Here, the natural variation of 13 root and 3 shoot traits was evaluated in 297 maize inbred lines and genome-wide association mapping was conducted to identify SNPs associated with target traits. All measured traits exhibited 2.02- to 21.36-fold variations. A total of 34 quantitative trait loci (QTLs) were detected for 13 traits, and each individual QTL explained 5.7% to 15.9% of the phenotypic variance. Three pleiotropic QTLs involving five root traits were identified; SNP_2_104416607 was associated with lateral root length (LRL), root surface area (RA), root length between 0 and 0.5mm in diameter (RL005), and total root length (TRL); SNP_2_184016997 was associated with RV and RA, and SNP_4_168917747 was associated with LRL, RA and TRL. The expression levels of candidate genes in root QTLs were evaluated by RNA-seq among three long-root lines and three short-root lines. A total of five genes that showed differential expression between the long- and short-root lines were identified as promising candidate genes for the target traits. These QTLs and the potential candidate genes are important source data to understand root development and genetic improvement of root traits in maize.

Potassium translocation combined with specific root uptake is responsible for the high potassium efficiency in vegetable soybean

2019 ◽  
Vol 70 (6) ◽  
pp. 516 ◽  
Author(s):  
Changkai Liu ◽  
Bingjie Tu ◽  
Xue Wang ◽  
Jian Jin ◽  
Yansheng Li ◽  
...  
Keyword(s):  
Uptake Rate ◽  
Root Length ◽  
Root Surface ◽  
Root Surface Area ◽  
Total Root Length ◽  
Vegetable Soybean ◽  
K Uptake ◽  
High Potassium ◽  
Source To Sink ◽  
Low K

Uptake of potassium (K) in crops depends mainly on the root system. Field, pot and hydroponic experiments were carried out to characterise root morphological traits and examine their roles in K uptake and utilisation of vegetable soybean (edamame) (Glycine max (L.) Merr.). Of 40 genotypes, two high K-efficiency (HKE) and two low K-efficiency (LKE) genotypes were identified and compared at two levels of K application: nil or 120 kg K2SO4 ha–1. HKE genotypes had shorter total root length and smaller root surface area and root volume than LKE genotypes, but responded earlier to low-K conditions by adjusting root architecture. In plants receiving nil K, total root length was increased by 10.4–21.8% for HKE genotypes but decreased by 5.5–9.5% for LKE genotypes at the V4 stage relative to plants receiving applied K. HKE genotypes were more efficient in redistributing K from source to sink tissue, especially from leaf. Of the total K in vegetative tissues, 35.0–46.4% was redistributed to seed in HKE genotypes, whereas only 19.7–28.2% was redistributed in LKE genotypes. HKE genotypes also had a higher specific K uptake rate (K uptake per unit root length), 1.6–1.7 times higher than LKE genotypes at the R5 stage. This indirectly indicated a stronger root K acquisition in HKE genotypes. This study suggests that future vegetable soybean improvement with greater K efficiency should be focused on the selection of higher K-redistribution rate and specific K-uptake rate.

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

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.

scholarly journals Interactions between stress response, carbohydrate metabolism, and defense pathways modulate rootstock root-dependent fire blight susceptibility in apple (Malus × domestica)

2019 ◽  
Author(s):  
Jugpreet Singh ◽  
Jack Fabrizio ◽  
Elsa Desnoues ◽  
Julliany Pereira Silva ◽  
Wolfgang Busch ◽  
...  
Keyword(s):  
Stress Response ◽  
Carbohydrate Metabolism ◽  
Fire Blight ◽  
Expression Patterns ◽  
Root Traits ◽  
Root Surface ◽  
Root Surface Area ◽  
Protein Kinase Activity ◽  
Root Mass ◽  
Molecular Relationships

Abstract Background Although it is known that resistant rootstocks facilitate management of fire blight disease, incited by Erwinia amylovora (Burr.) Winslow et al., of apple scion cultivars, the role of rootstock root traits in providing systemic defense against E. amylovora is unclear. In this study, the hypothesis that rootstocks of higher root mass provide higher tolerance to fire blight infection in apples is tested. Several apple scion cultivars grafted onto a single rootstock genotype and non-grafted ‘M.7’ rootstocks of varying root mass are used to assess phenotypic and molecular relationships between root traits of rootstocks and fire blight susceptibility of apple scion cultivars. Results It is observed that different root traits display significant (p < 0.05) negative correlations with fire blight susceptibility. In fact, root surface area partially dictates differential levels of fire blight susceptibility of ‘M.7’ rootstocks. Furthermore, contrasting changes in gene expression patterns of diverse molecular pathways accompany observed differences in levels of root-driven fire blight susceptibility. It is noted that a singular co-expression gene network consisting of genes from defense, carbohydrate metabolism, protein kinase activity, oxidation-reduction, and stress response pathways modulates root-dependent fire blight susceptibility in apple. In particular, WRKY75 and UDP-glycotransferase are singled-out as hub genes deserving of further detailed analysis. Conclusions It is proposed that low root mass may incite resource-limiting conditions to activate carbohydrate metabolic pathways, which reciprocally interact with plant immune system genes to elicit differential levels of fire blight susceptibility.

scholarly journals Plant Growth Regulator Effects on Germination and Root Traits of ‘Lambada’ and ‘Don Victor’ Onion Cultivars

HortScience ◽  
2017 ◽  
Vol 52 (12) ◽  
pp. 1759-1764
Author(s):  
Maria A. Macias-Leon ◽  
Daniel I. Leskovar
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Synergistic Effects ◽  
Field Performance ◽  
Root Traits ◽  
Root Surface ◽  
Root Diameter ◽  
Root Surface Area ◽  
Relative Growth ◽  
Relative Growth Rates

Onions (Allium cepa L.) are easily outcompeted by weeds because of slow germination and relative growth rates. Therefore, high percentage of seed germination and root vigor are important traits to improve field performance. The effects of exogenous plant growth regulators (PGRs), 2-chloroethylphosphonic acid (ethephon, Eth), indole-3-acetic acid (IAA), trans-zeatin (tZ), and 1-aminocyclopropane-1-carboxylic acid (ACC) were evaluated on the germination and root growth of ‘Don Victor’ (yellow) and ‘Lambada’ (red) onion seedlings. Seeds were soaked for 10 hours in hormonal solutions and water (hydro-priming). Seed germination improved with Eth (30 and 100 μm), Eth (100 μm) + IAA (10 μm), and IAA (3 μm) treatments. Root surface area (RSA) increased in response to Eth at 30 and 100 μm, Eth + IAA, and 3 μm IAA. Root length (RL) and root diameter (RD) were enhanced by 1 μm tZ and 100 μm ACC. Eth reduced RL and RD, whereas IAA showed no effects. A subsequent experiment evaluated synergistic effects of different PGRs. Treatment of seeds with ACC (250 μm) + tZ (0.5 μm) and ACC (250 μm) + tZ (0.5 μm) + Eth (20 μm) enhanced RL and RD. RSA was unaffected by ACC + tZ + Eth. The results suggest that exogenous PGRs could be useful to enhance germination, RL, and RSA of onion seedlings.

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 Study on measurement method for apple root morphological parameters based on Labview

Plant Methods ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Yu Liu ◽  
Ji Qian ◽  
Xin Yang ◽  
Bao Di ◽  
Juan Zhou
Keyword(s):  
Root System ◽  
Surface Area ◽  
Relative Error ◽  
Root Length ◽  
Average Diameter ◽  
Root Surface ◽  
Root Diameter ◽  
Root Surface Area ◽  
Root Volume ◽  
Seedling Roots

Abstract Background Traditional measurements of apple seedling roots often rely on manual measurements and existing root scanners on the market. Manual measurement requires a lot of labor and time, and subjective reasons may cause the uncertainty of data; root scanners have limited scanning size and expensive. In case of fruit roots, coverage and occlusion issues will occur, resulting in inaccurate results, but our research solved this problem. Results The background plate was selected according to the color of the seedling roots; the image of the roots of the collected apple seedlings was preprocessed with Vision Development Module by combining image and Labview. The root surface area, average root diameter, root length and root volume of apple seedlings were measured by combining root characteristic parameters algorithm. In order to verify the effectiveness of the proposed method, a set of measurement system for root morphology of apple seedlings was designed, and the measurement result was compared with the Canadian root system WinRHIZO 2016 (Canada). With application of SPSS v22.0 analysis, the significance P > 0.01 indicated that the difference was not significant. The relative error of surface area was less than 0.5%. The relative error of the average diameter and length of the root system was less than 0.1%, and the relative error of the root volume was less than 0.2%. Conclusions It not only proved that the root surface area, average root diameter, root length and root volume of apple seedlings could be accurately measured by the method described herein, which was handy in operation, but also reduced the cost by 80–90% compared with the conventional scanner.

Stand morphology of Townsville lucerne (Stylosanthes humilis) : Seasonal growth and root development

1968 ◽  
Vol 8 (34) ◽  
pp. 533 ◽  
Author(s):  
BWR Torssell ◽  
JE Begg ◽  
CW Rose ◽  
GF Byrne
Keyword(s):  
Root Length ◽  
Lateral Roots ◽  
Heavy Rain ◽  
Root Surface ◽  
Root Surface Area ◽  
General Description ◽  
Seasonal Growth ◽  
Wet Season ◽  
Average Growth ◽  
Stylosanthes Humilis

This paper describes the seasonal growth and morphology of a four-year-old pasture of Townsville lucerne (Stylosanthes humilis) used in a detailed microenvironmental study conducted at Katherine, N.T., during the 1966-67 wet season. Rapid germination and penetration of the tap root followed an early storm rain of 38 mm at the end of September, and most of the seedlings survived the next seven weeks without rain. A second germination followed heavy rain at the end of November, and by the end of December the main development of lateral roots commenced and the rate of shoot development increased. The highest average growth rate, 31 g/m2/day for the period March 31-April 14, was after the last rain of the season and preceded by ten weeks of above average rainfall. Growth continued for a further two weeks while the roots continued to deplete available soil water. During the main period of growth, approximately 80 per cent of root length and 70 per cent of root surface area was in the top 30 cm of soil. The density of root length varied very little below 30 cm. Growth and development are discussed in relation to grass competition and drought adaptation, and fitted to a general description of the life cycle of Townsville lucerne under northern Australian conditions.

scholarly journals Determination of root properties of saplings belong to two boxwood species (Buxus sempervirens and Buxus balearica) by image processing technique

2021 ◽  
pp. 20-24
Author(s):  
Ömer Sarı
Keyword(s):  
Surface Area ◽  
Root Length ◽  
Root Surface ◽  
Root Diameter ◽  
Image Processing Technique ◽  
Root Surface Area ◽  
Root Tips ◽  
Root Volume ◽  
Buxus Sempervirens ◽  
Second Year

The study was carried out to determine the root architectural characteristics of the one-year saplings of two species of boxwood (Buxus sempervirens L. and Buxus balearica Lam.), which are endangered and natural plants of Turkey, in the greenhouse environment using the WinRhizo root analysis program and scanner. Total root length (cm), root surface area (cm2), root volume (cm3), average root diameter (mm), number of tips, number of forks and number of root crossings were determined in the study. According to the results of the study, the increase in temperature and decrease in humidity values in the second year of both species were effective on the root architectural features. As a result of this effect, the second year root length (3810 cm), number of root tips (2299), number of forks (7007) and number of root crossings (696) increased, root diameter (1.4 mm), root surface area (2158 cm2) and root volume (8 cm3) decreased. As a result, it has been concluded that species can make changes in their root parameters to adapt to different conditions and their adaptability is high. In general, the best results in root architectural parameters were obtained from Buxus balearica on the basis of species.

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