root diameter
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Author(s):  
Vivian Ronquete ◽  
Alexandre Sigrist de Martin ◽  
Karin Zuim ◽  
Thais Machado de Carvalho Coutinho ◽  
Eduardo Fagury Videira Marceliano ◽  
...  

Abstract Objective This study compared the ProTaper Next (PTN; Dentsply Sirona, Tulsa, Oklahoma, United States) and HyFlex EDM (HEDM; Coltene/Whaledent AG, Alstätten, Switzerland) systems using micro–computed tomography (CT). Materials and Methods Twenty-one mesial roots classified as Vertucci's type IV from extracted mandibular first molars with curvatures between 20 and 40 degrees were selected. The teeth were scanned using a micro-CT before and after root canal preparation by both systems, applied to the same root, in alternating canals. The following parameters were analyzed: canal centering, apical transportation, root canal diameter/root diameter. Results No statistically significant differences between both systems were observed for any of the assessed morphological parameters (p > 0.05). All canals presented diameter enlargement of more than 40% in relation to root diameter in the cervical and middle segments. No statistically significant difference was noted between the HEDM and PTN groups. The wear percentage for the HEDM group in the cervical and middle thirds were 49.66 ± 8.65 and 46.48 ± 14.29, respectively, and 51.02 ± 11.81 and 45.48 ± 10.79 for the PTN group, respectively. Conclusion Both systems displayed similar mandibular molar mesial canals preparation, with no differences noted for any of the assessed parameters. Both groups showed increased canal diameter in the cervical and middle thirds by more than 40%.


2022 ◽  
Vol 12 ◽  
Author(s):  
Cunguo Wang ◽  
Ivano Brunner ◽  
Junni Wang ◽  
Wei Guo ◽  
Zhenzhen Geng ◽  
...  

Trees can build fine-root systems with high variation in root size (e.g., fine-root diameter) and root number (e.g., branching pattern) to optimize belowground resource acquisition in forest ecosystems. Compared with leaves, which are visible above ground, information about the distribution and inequality of fine-root size and about key associations between fine-root size and number is still limited. We collected 27,573 first-order fine-roots growing out of 3,848 second-order fine-roots, covering 51 tree species in three temperate forests (Changbai Mountain, CBS; Xianrendong, XRD; and Maoershan, MES) in Northeastern China. We investigated the distribution and inequality of fine-root length, diameter and area (fine-root size), and their trade-off with fine-root branching intensity and ratio (fine-root number). Our results showed a strong right-skewed distribution in first-order fine-root size across various tree species. Unimodal frequency distributions were observed in all three of the sampled forests for first-order fine-root length and area and in CBS and XRD for first-order fine-root diameter, whereas a marked bimodal frequency distribution of first-order fine-root diameter appeared in MES. Moreover, XRD had the highest and MES had the lowest inequality values (Gini coefficients) in first-order fine-root diameter. First-order fine-root size showed a consistently linear decline with increasing root number. Our findings suggest a common right-skewed distribution with unimodality or bimodality of fine-root size and a generalized trade-off between fine-root size and number across the temperate tree species. Our results will greatly improve our thorough understanding of the belowground resource acquisition strategies of temperate trees and forests.


2022 ◽  
Vol 6 (1) ◽  
pp. 1-4
Author(s):  
Shah Masaud Khan ◽  
Abid Ali ◽  
Ijaz Hussain ◽  
Muhammad Saeed ◽  
Izhar Hussain ◽  
...  

The research was carried out on the “Evaluation of Radish genotypes with special study on sowing geometry at Agricultural Research Institute, Tarnab Peshawar”. The experiment was laid out in randomized complete block design having three replications. The experiment comprised with two factors, one was sowing dates(19th Oct., 4th., Nov., and 19th Nov) and the other was different genotypes (Mino, Local Red and Local White). The data were recorded on Days to germination, Germination (%), Days to edible maturity, Number of leaves plant-1, Leaf length plant-1 (cm), Root length plant-1 (cm), Root diameter plant-1 (cm), root fresh weight (g), Plot weight (kg) and yield (t ha-1). Sowing dates significantly affected all yield parameters. Sowing of radish on 19th October has more number of Leaves (17.44 leaves) plant-1, Leaf length plant(22.611 cm), root length plant-1(24.058 cm), root diameter plant-1(3.12 cm) fresh root weight (503.95g), the maximum plot weight (50.90 kg plot-1) and higher yield (62.36t ha-1) was observed whereas the crop sown on 19th November showed the minimum days to germination (8.88 days), germination percentage (96.88%) and minimum days to maturity (53 days). Among genotypes Mino take minimum days to germinate(8.22 days), maximum germination percentage (99.22), minimum days to maturity (52.778), maximum number of leaves (19.44 leaves), leaf length (23.422 cm), greater root length (24.588 cm), maximum root diameter (3.53 cm), higher root fresh weight (536.62g), higher weight per plot (52.22 kg) and maximum yield (63.54t ha-1). The results emphasized that the suitable time of sowing for Mino genotype is 19th October for Peshawar.


Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1797
Author(s):  
Zuwang Li ◽  
Zhi Liu ◽  
Guoqiang Gao ◽  
Xinlei Yang ◽  
Jiacun Gu

Tree age has an important effect on the form and function of fine roots. Previous studies have focused on the variations in root morphological and chemical traits among tree ages, while less attention has been given to the physiological traits, impeding a full understanding of the relationship between root resource acquisition strategy and tree age. Here, we measured root morphological (diameter, specific root length, specific root area and tissue density), chemical (nitrogen concentration) and physiological (respiration and exudation rate) traits of young, middle-aged and mature trees of Fraxinus mandshurica in a temperate secondary forest in northeastern China. Our overall aim was to determine how root traits and related resource acquisition strategy change with tree age. The results showed that from young to mature trees, root diameter gradually increased, but specific root length, specific root area, root nitrogen concentration, respiration and exudation rates all decreased, and the significant differences were mainly found between young and mature trees. Pearson’s correlation analysis revealed that the relationships of root respiration and exudation rates to root morphological and chemical traits depended on tree age and the specific traits examined, but these correlations were all significant except for root tissue density when the data were pooled across all tree age classes. Principal component analysis (PCA) showed that the conservative traits represented by root diameter, and the acquisitive traits such as root respiration and exudation rates and related morphological and chemical traits, occupied two ends of the first axis, respectively, while root tissue density occupied one end of the second axis, partially confirming the conceptual framework of “root economics space”. Standardized major axis (SMA) analysis of root exudation and respiration rates showed that young trees allocated more root carbon flux to the formation of root exudation, compared to middle-aged and mature trees. Our findings suggest that root resource acquisition strategy in F. mandshurica appears to shift from an absorptive to conservative strategy associated with increasing tree age, which may have substantial consequences for individual growth and interspecific competition, as well as belowground carbon allocation in ecosystems.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mengmeng Wang ◽  
Shu Zhou ◽  
Junyang Lu ◽  
Anqi Xu ◽  
Yuan Huang ◽  
...  

Low-temperature stress is the main limiting factor of cucurbit crop cultivation as it affects crop yield and quality. The identification of genes involved in cold tolerance is a crucial aspect of pumpkin rootstock breeding. Here, we examined the function of a pumpkin Regulator of Chromosome Condensation 1 (CmRCC1) gene in the root development and cold stress responses of tobacco (Nicotiana benthamiana). CmRCC1 expression was differentially induced in pumpkin root, stem, and leaf under cold stress. Transient transformation showed that CmRCC1 is located in the nucleus. CmRCC1 overexpression in tobacco increased the gravitropic set-point angle in lateral roots, as well as root diameter and volume. The expression of auxin polar transport factors, PIN1 and PIN3, decreased and increased in CmRCC1-overexpressed plants, respectively. Yeast two-hybrid verification and luciferase complementation imaging assay showed that CmRCC1 interacts with CmLAZY1. Furthermore, the decreases in maximum quantum yield of PS II, the effective quantum yield of PS II, and electron transfer rate and the increases in quantum yield of nonregulated energy dissipation and malondialdehyde content were compromised in transgenic plants compared with wild-type plants under cold stress. The results suggest that CmRCC1 plays an important role in the regulation of root architecture and positively modulates cold tolerance.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wen Luo ◽  
Xiaoyu Zai ◽  
Jieyu Sun ◽  
Da Li ◽  
Yuanli Li ◽  
...  

Root diameter and rooting depth lead to morphological and architectural heterogeneity of plant roots; however, little is known about their effects on root-associated microbial communities. Bacterial community assembly was explored across 156 samples from three rhizocompartments (the rhizosphere, rhizoplane, and endosphere) for different diameters (0.0–0.5 mm, 0.5–1.0 mm, 1.0–2.0 mm, and>2.0 mm) and depths (0–5 cm, 5–10 cm, 10–15 cm, and 15–20 cm) of soybean [Glycine max (L.) Merrill] root systems. The microbial communities of all samples were analyzed using amplicon sequencing of bacterial 16S rRNA genes. The results showed that root diameter significantly affected the rhizosphere and endosphere bacterial communities, while rooting depth significantly influenced the rhizosphere and rhizoplane bacterial communities. The bacterial alpha diversity decreased with increasing root diameter in all three rhizocompartments, and the diversity increased with increasing rooting depth only in the rhizoplane. Clearly, the hierarchical enrichment process of the bacterial community showed a change from the rhizosphere to the rhizoplane to the endosphere, and the bacterial enrichment was higher in thinner or deeper roots (except for the roots at a depth of 15–20 cm). Network analysis indicated that thinner or deeper roots led to higher bacterial network complexity. The core and keystone taxa associated with the specific root diameter class and rooting depth class harbored specific adaptation or selection strategies. Root diameter and rooting depth together affected the root-associated bacterial assembly and network complexity in the root system. Linking root traits to microbiota may enhance our understanding of plant root-microbe interactions and their role in developing environmentally resilient root ecosystems.


Author(s):  
Igor N. de Castro ◽  
Silvânio R. dos Santos ◽  
Marcelo R. dos Santos ◽  
Polyanna M. de Oliveira ◽  
Ignacio Aspiazú ◽  
...  

ABSTRACT Knowledge of the cactus pear root distribution system can improve management of the plant by defining the areas of soil best suited to fertilizer application and the installation of soil moisture sensors under irrigation. Thus, the aim of the present study was to assess the root distribution of cactus pear genotypes under different water replacement levels. To that end, a field experiment was conducted in a randomized block design, using genetic material from two cactus pear genotypes (Opuntia fícus-indica Mill. and Nopalea cochenillifera Salm-Dyck) and six water replacement levels based on reference evapotranspiration - ET0 (T1, no irrigation; T2, 15%; T3, 30%; T4, 45%; T5, 60% and T6, 75% of ET0), arranged in split-plot, with irrigation treatments allocated to the plots and the genetic material to the sub-plots, and three replicates. The roots of the cultivars were collected for analysis of root length density (RLD) 390 days after planting. The RDL of very fine roots declines as depth and distance from the plant base increases and total, fine, small and medium RDL rise at higher water replacement levels; 75% of ET0 near the plant base increases RDL; all the root diameter classes are concentrated at a distance of 0-0.20 m from the plant base and depth of 0.10 to 0.25 m; the RDL percentage is higher for the Gigante genotype and Miuda exhibits better root distribution.


2021 ◽  
Vol 10 (6) ◽  
pp. 3452-3459
Author(s):  
Mohd Khairi Nordin ◽  
Mohammad Farid Saaid ◽  
Nooritawati Md Tahir ◽  
Ahmad Ihsan Mohd Yassin ◽  
Megat Syahirul Amin Megat Ali

Precision agriculture aims to maximize yield with optimum resources. Vast majority of natural systems are acknowledged as complex and non-linear. However, prior to formulation of precise models, linearity tests are performed to validate plant behavior. This study has presented proof that the water uptake system in monopodial orchid is indeed non-linear. The change in physical growth of root and stem due to temperature and relative humidity factors are observed. The work focused on Ascocenda Fuchs Harvest Moon x (V. Chaophraya x Boots) orchid hybrid. Three complementary methods are presented: linearity tests through 1) regression fitting; 2) scatter plots; and 3) cross-correlation function tests. Root diameter, stem diameter, temperature, and relative humidity are logged at 15 minutes interval for a duration of 71 days. The polynomial equations derived for root diameter and stem diameter changes attained strong regression coefficients. The non-linear behavior is further confirmed by the scatter plots where no linear associations are present between the independent and dependent variables. Subsequently, the cross-correlation function tests conducted on temperature-root diameter, temperature-stem diameter, relative humidity-root diameter, and relative humidity-stem diameter combinations also revealed weak correlation. Despite using different techniques, the behavior of physical changes has been consistently proven to be non-linear.


2021 ◽  
Author(s):  
Daba Etana ◽  
Amsalu Nebiyu ◽  
Zeleke Wondimmu ◽  
Morgan L. Ruelle

Abstract Aims Common bean is an important source of food and fodder and is used to improve soil fertility when integrated in cropping systems through intercropping or rotation. Although widely grown by smallholders in Ethiopia, its productivity is constrained by several factors including soil acidity, which limits nutrient availability and uptake. The negative effects of soil acidity may be mediated by root system morphology and structure. Therefore, the aim of this study was to determine if root traits in common bean are associated with tolerance to soil acidity. Methodology The study was laid out in a split-plot design, whereby soil amendment practices with phosphorus (+P or -P) and liming (+lime or –lime) and their combinations were assigned to main plots and varieties to subplots. Two improved varieties (Nasir and Deme) and two farmers’ varieties (Polpole and Pantarkin) of common bean were evaluated under each soil amendment practice. Results Farmers’ variety Polpole produced significantly (p< 0.05) more hypocotyl roots (14.17) with a wider hypocotyls angle (5.87°) than other varieties. In addition, Polpole had a larger tap root diameter (2.57 mm) and length (34.10 cm) in plots amended with P. The improved variety Deme showed a higher number of basal roots (14.0) and basal root whorls (4.20) as well as lower basal root angle (0-15°) in plots amended with P and lime. Analyses demonstrate that common bean varieties differ in their ability to tolerate soil acidity due to differences in their root morphological and structural traits. Conclusion The results suggest an opportunity to identify and further develop acid tolerant varieties for low input farming systems to improve and enhance bean productivity and efficiency of the agro ecosystem at large.


Author(s):  
Mepivoseth Castelán-Estrada ◽  
Emeterio Payró de la Cruz ◽  
Guadalupe De los Santos-López ◽  
Samuel Córdova-Sánchez ◽  
Juan F. Gómez-Leyva ◽  
...  

E Objective: A study was carried out in the Ingenio Santa Rosalía sugar mill supply area with the aim of identifying the soil subunits cultivated with sugar cane and to quantify the degree of mycorrhization of Saccharum officinarum. Design/Methodology/Approach: Rhizosphere samples were collected at a depth of 0-30 cm and root segments with diameters of ≤ 1 mm and 1-2.0 mm were studied. The intersect method and the fungal structures method were comparatively analyzed to determine the mycotrophic state of the roots. The study also quantified the number of spores in the soils and classified the morpho-species of vesicular-arbuscular mycorrhiza (VAM). Results: The results show that seven soil subunits exist in the area, but the intersect method did not detect differences in colonization by root diameter or by root colonization ( = 68.5%). For its part, the fungal structures method showed differences in colonization between soil subunits ( = 69.5%), being higher in thin roots, and statistical differences wer found for vesicles and spores. At the sites, an average of 696 spores was quantified per 100 g of soil, which indicates a high presence of vesicular-arbuscular mycorrhizal fungi in the study area. Finally, six species of mycorrhizae were identified, of which four are present in various soil subunits: Glomus aff. deserticola, Glomus etunicatum, Glomus viscosum, and Paraglomus occultum. Study Limitations/Implications: This was an exploratory study that indicates the potential of VAM. Findings/Conclusions: The presence of hyphae, vesicles, arbuscules, and spores indicates that there is an active mycotrophic process between VAM and sugarcane cultivation in the soils of the study area.


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