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

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.

Download Full-text

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

Plant Methods ◽

10.1186/s13007-019-0535-4 ◽

2019 ◽

Vol 15 (1) ◽

Cited By ~ 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.

Download Full-text

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

HortTechnology ◽

10.21273/horttech04098-18 ◽

2018 ◽

Vol 28 (5) ◽

pp. 629-636 ◽

Cited By ~ 4

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.

Download Full-text

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

Turkish Journal of Food and Agriculture Sciences ◽

10.14744/turkjfas.2021.005 ◽

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.

Download Full-text

The Role of Root Morphology and Pulling Direction in Pullout Resistance of Alfalfa Roots

Frontiers in Plant Science ◽

10.3389/fpls.2021.580825 ◽

2021 ◽

Vol 12 ◽

Author(s):

Qihong Yang ◽

Chaobo Zhang ◽

Pengchong Liu ◽

Jing Jiang

Keyword(s):

Root System ◽

Surface Area ◽

Root Length ◽

Pullout Test ◽

Root Surface ◽

Root Diameter ◽

Root Surface Area ◽

Pullout Resistance ◽

Significant Difference ◽

Morphological Indices

There is a growing consensus on soil conservation by mechanics of plant root system. In order to further study how root system exerts its mechanical properties during soil reinforcing process and which morphological indicator is suitable for reflecting pullout resistance, in-situ vertical pullout test (VPT) and 45° oblique pullout test (OPT) were performed on alfalfa (Medicago sativa L.) roots in the loess area. The results showed that the failure mode of alfalfa roots was pulling out in this study. The peak pullout resistance of the roots increased with root diameter, root length and root surface area, and power law relationships were observed between the pullout resistance and the morphological indices: root diameter, root length and root surface area. The maximum gray relational degree of the morphological indices was 0.841 (VPT) and 0.849 (OPT) for root surface area, suggesting that root surface area was a more significant root morphological index affecting root pullout resistance than root diameter and root length, and was more suitable for characterizing the difference in peak pullout resistance of roots with different size. The index could be used to validate the methods for predicting root pullout capacity. The value of peak pullout resistance was 17.2 ± 2.3 N in VPT test and 28.2 ± 3.8 N (mean ± SE) in OPT test, and a significant difference was observed between the two tests, which showed that the pulling direction significantly affected the peak pullout resistance of alfalfa roots. Vertical pullout test, giving the safety margin, was suggested to determine root pullout resistance for estimate of root reinforcement.

Download Full-text

Root morphological, Cd accumulation and tolerance characteristics of 2 Dianthus caryophyllus cultivars under Cd stress

E3S Web of Conferences ◽

10.1051/e3sconf/202127104012 ◽

2021 ◽

Vol 271 ◽

pp. 04012

Author(s):

Jiong Wu ◽

Changdi Ke ◽

Yanqun Zu ◽

Yu Din ◽

Taiting Li

Keyword(s):

Surface Area ◽

Root Exudates ◽

Root Length ◽

Dianthus Caryophyllus ◽

Cadmium Stress ◽

Root Surface ◽

Root Diameter ◽

Root Surface Area ◽

Root Volume ◽

Projected Area

For studying the physiological response of two different Dianthus caryophyllus cultivars on Cd stress, pot experiment was carried out to measure proline and glutathione in leaves, five types of organic acids in root exudates (oxalic acid, malic acid, acetic acid, tartaric acid, citric acid), soluble sugars and free amino acids, root length, root surface area, root volume, root projected area and Cadmium content in soil, plant roots and aboveground. According to the effects of cadmium stress on the physiological and biochemical characteristics of two Dianthus caryophyllus, the results showed that: the growth of two cultivars are affected, “Master” and “Xiao Yan” are manifested as plant height, leaf, flower buds and biomass decreased, but the “Master” by the stronger inhibitory effect. The root length, total root surface area, total root projected area, and average root diameter of the “Master” increased under cadmium stress, but the root volume decreased. However, the root length, total root surface area, root volume, and root projected area of the “Xiao Yan” under cadmium stress decreased, while the average root diameter increased. The glutathione in the leaves of the two cultivars decreased, the proline content of the leaves of the “Xiao Yan” increased, while that of the “Master” decreased. In the root exudates, the free amino acid content of the two cultivars are reduced, and the secretion of organic acids is also inhibited (except for the citric acid secreted in the “Master”), while the soluble sugar content in the root exudates is expressed as “Xiao Yan” increased, and the “Master” decreased. According to the physiological response to the two cultivars under cadmium stress, the “Xiao Yan” is more suitable for soil restoration in the mining area of Lanping area.

Download Full-text

Complete root specimen of plants grown in soil-filled root box: sampling, measuring, and staining method

Plant Methods ◽

10.1186/s13007-021-00798-3 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Takuya Koyama ◽

Shun Murakami ◽

Toshihiko Karasawa ◽

Masato Ejiri ◽

Katsuhiro Shiono

Keyword(s):

Root System ◽

Surface Area ◽

Visual Information ◽

Physiological Function ◽

Physiological Activity ◽

Root Traits ◽

Arbuscular Mycorrhizal ◽

Spatial Arrangement ◽

Root Surface ◽

Root Surface Area

Abstract Background Detailed datasets containing root system and its architecture in soil are required to improve understanding of resource capture by roots. However, most of the root study methods have paid little attention to make and preserve whole root specimens. This study introduces root system sampling equipment that makes the entire root specimen with minimum impairment and without displacement of the spatial arrangement of the root system in root boxes. The objectives are to assess: whether the equipment can rapidly sample the entire root system; whether root surface area is measurable from a scanned digital image of the root specimen; and whether staining of the entire root specimens would provide multidimensional visual information on the interaction between soil and physiological function of root system architecture (RSA). For validation, we examined the root response of two soybean cultivars to arbuscular mycorrhizal (AM) inoculation and the effect of waterlogging stress on the physiological activity of buckwheat RSA. Results The root boxes allowed soybean and buckwheat plants to grow uniformly across the replications. Both species showed significant differences between cultivars and/or among treatments in shoot and root traits. The equipment enabled to sample the whole-root specimens of soybean and buckwheat, where the tips of the fine roots were alive (diameter < 0.2 mm). Also, the whole root specimens of soybean were made in about 7 min. The root surface area calculated from the scanned soybean specimens showed a significant correlation with that calculated from the roots spread out in water (a common method). Staining of the soybean root specimens enabled us to observe the localized root proliferation induced by AM colonization. Moreover, staining of the buckwheat root specimens made it possible to examine the respiratory activity of each root at different depths. Conclusions The present method realized: fast and accurate production of the whole root specimen and precise calculation of the specimens’ root surface area. Moreover, staining of the root specimens enabled analyzing the interaction between soil and physiological function of RSA. The evaluation of root traits, using our methods, will contribute to developing agronomic management and breeding program for sustainable food production.

Download Full-text

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

Genes ◽

10.3390/genes10100773 ◽

2019 ◽

Vol 10 (10) ◽

pp. 773 ◽

Cited By ~ 1

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.

Download Full-text

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

The Rangeland Journal ◽

10.1071/rj18099 ◽

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.

Download Full-text

Improvements in the Root Morphology, Physiology, and Anatomy of Platycladus orientalis Seedlings from Air-root Pruning

HortScience ◽

10.21273/hortsci13375-18 ◽

2018 ◽

Vol 53 (12) ◽

pp. 1750-1756

Author(s):

Zhipei Feng ◽

Xitian Yang ◽

Hongyan Liang ◽

Yuhua Kong ◽

Dafeng Hui ◽

...

Keyword(s):

Root System ◽

Surface Area ◽

Root Length ◽

Specific Root Length ◽

Experimental Period ◽

Root Surface ◽

Root Surface Area ◽

Root Pruning ◽

Root Tips ◽

Platycladus Orientalis

Air-root pruning (AP) has been identified as an effective technique for enhancing root growth and development. However, little information is available regarding the temporal changes in the root system of Platycladus orientalis (L.) Franco under AP. We performed integrated morphological, physiological, and anatomical analyses of the roots in P. orientalis seedlings that had been air-root pruned for 120, 150, and 190 days. Our results found that the whole root length, number of root tips, and root surface area of AP seedlings at 120, 150, and 190 days were higher than those of the non–root-pruned (NP) seedlings (P < 0.05), but the average root diameter did not differ significantly between the treatments. Compared with NP treatment, AP increased the root length, surface area, number of tips, and specific root length of the ≤0.5 mm diameter roots in P. orientalis during the experimental periods (P < 0.05), but those of 0.5- to 1-mm-diameter roots were only increased on day 190 (P < 0.05). The AP plants also exhibited higher root vitality and proportion of live fine roots than the NP plants (P < 0.05). Our anatomical evaluation of the ≤0.5 mm roots and taproots revealed features that could account for the morphological differences found between the AP and NP plants. In conclusion, our results indicate that air-root pruning induced changes in the roots that promote the root system development in P. orientalis compared with the NP treatment during the experimental period. These results thus provide experimental evidence to support the use of AP in P. orientalis seedlings.

Download Full-text

ROOTING OF Inga edulis Mart. (LEGUMINOSAE-MIMOSOIDEAE) MINI-CUTTINGS

FLORESTA ◽

10.5380/rf.v50i1.61297 ◽

2019 ◽

Vol 50 (1) ◽

pp. 1091

Author(s):

Marciana Christo Berude ◽

Emanuel França Araújo ◽

Bruna Tomaz Sant'Ana ◽

Rodrigo Sobreira Alexandre ◽

Elzimar De Oliveira Gonçalves

Keyword(s):

Surface Area ◽

Root Length ◽

Dry Matter ◽

Weighted Average ◽

Specific Root Length ◽

Root Surface ◽

Root Surface Area ◽

Root Volume ◽

Inga Edulis ◽

Fine Root Length

Seeds of the species Inga edulis are recalcitrant and lose viability quickly, which restricts seedling production at only a certain time of the year. Thus, this study aimed to analyze the potential of mini-cutting and the influence of different indole-3-butyric acid (IBA) concentrations on the vegetative propagation of Inga edulis. The vegetative material was collected from juvenile plants from a clonal mini-garden. The experiment was carried out in a completely randomized design, with five replications and each experimental unit with eight cuttings. Treatments consisted of different IBA concentrations (0, 1000, 2000, 4000, and 8000 mg kg−1). The percentage of live and rooted mini-cuttings, number of roots emitted from the base, longest root length, total number of roots, fine root length, total root length, root surface area, weighted average root diameter, root volume, shoot dry matter, root dry matter, total dry matter, specific root length, specific root surface area, and root density were analyzed after 45 days in a greenhouse. All Inga edulis mini-cuttings survived, and rooting was over 85%. IBA concentrations had no significant effect on most of the analyzed variables. However, exogenous auxin concentration between 2000 and 4636.96 mg kg−1 provided mini-cuttings with a higher number of roots, surface area, and root volume. Rooting of juvenile Inga edulis mini-cuttings may occur without the use of IBA.

Download Full-text