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 Effect of Transplanting Practices on Growth and Water Relations of ‘Colt’ Cherry Trees During Reestablishment

1989 ◽  
Vol 7 (1) ◽  
pp. 41-45 ◽  
Author(s):  
T.G. Ranney ◽  
N.L. Bassuk ◽  
T.H. Whitlow
Keyword(s):  
Growth Rate ◽  
Water Loss ◽  
Dry Weight ◽  
Root Surface ◽  
Area Ratio ◽  
Root Surface Area ◽  
Plant Water ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Cherry Trees

Abstract Dormant pruning, a film antitranspirant, and soil-applied paclobutrazol were evaluated as transplanting treatments in newly transplanted ‘Colt’ cherry trees under irrigated and water-stressed conditions. Under irrigated conditions all three treatments were effective in reducing plant water loss. However, all three treatments resulted in large reductions in mean growth rate, mean relative growth rate, root dry weight, and root surface area. The pruning treatment had no effect on the leaf area:root area ratio whereas the antitranspirant treatment resulted in an increased leaf area:root area ratio, a response considered undesirable. Paclobutrazol decreased the leaf area:root area ratio but also induced abnormal radial enlargement of plant roots. Under water-stressed conditions all three treatments were effective in reducing plant water loss and were successful in delaying plant water stress. Both pruned and antitranspirant treated plants had improved relative growth rates as compared to the controls.

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 Phytase-Producing Rahnella aquatilis JZ-GX1 Promotes Seed Germination and Growth in Corn (Zea mays L.)

2021 ◽  
Vol 9 (8) ◽  
pp. 1647
Author(s):  
Gui-E Li ◽  
Wei-Liang Kong ◽  
Xiao-Qin Wu ◽  
Shi-Bo Ma
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Biomass Accumulation ◽  
Root Surface ◽  
Phosphorus Concentration ◽  
Maize Seedlings ◽  
Total Phosphorus Concentration ◽  
Rahnella Aquatilis ◽  
Maize Seeds

Phytase plays an important role in crop seed germination and plant growth. In order to fully understand the plant growth-promoting mechanism by Rahnella aquatilis JZ-GX1，the effect of this strain on germination of maize seeds was determined in vitro, and the colonization of maize root by R. aquatilis JZ-GX1 was observed by scanning electron microscope. Different inoculum concentrations and Phytate-related soil properties were applied to investigate the effect of R. aquatilis JZ-GX1 on the growth of maize seedlings. The results showed that R. aquatilis JZ-GX1 could effectively secrete indole acetic acid and had significantly promoted seed germination and root length of maize. A large number of R. aquatilis JZ-GX1 cells colonized on the root surface, root hair and the root interior of maize. When the inoculation concentration was 107 cfu/mL and the insoluble organophosphorus compound phytate existed in the soil, the net photosynthetic rate, chlorophyll content, phytase activity secreted by roots, total phosphorus concentration and biomass accumulation of maize seedlings were the highest. In contrast, no significant effect of inoculation was found when the total P content was low or when inorganic P was sufficient in the soil. R. aquatilis JZ-GX1 promotes the growth of maize directly by secreting IAA and indirectly by secreting phytase. This work provides beneficial information for the development and application of R. aquatilis JZ-GX1 as a microbial fertilizer in the future.

scholarly journals Effect of Aqueous Neem Leaf Extracts in Controlling Fusarium Wilt, Soil Physicochemical Properties and Growth Performance of Banana (Musa spp.)

2021 ◽  
Vol 13 (22) ◽  
pp. 12335
Author(s):  
Ung Yi ◽  
Sakimin Siti Zaharah ◽  
Siti Izera Ismail ◽  
Mohamed Hanafi Musa
Keyword(s):  
Physicochemical Properties ◽  
Growth Performance ◽  
Fusarium Wilt ◽  
Root Surface ◽  
Root Diameter ◽  
Plant Diseases ◽  
Root Surface Area ◽  
Soil Physicochemical Properties ◽  
Leaf Extracts ◽  
Root Shoot Ratio

Neem leaf extracts (NLEs) have frequently been used to inhibit plant diseases and for the development of bio-fertilizer, leading to the commercial exploitation of this tree. However, previous studies have indicated contradictory outcomes when NLE was used as an antifungal disease treatment and bio-fertilizer applied through the soil on several crops, including banana. Therefore, the present investigation was undertaken to examine the physicochemical properties of soil, the growth performance of crops, and the severity of diseases caused by Fusarium oxysporum (Foc) on Cavendish bananas treated with aqueous NLE. Banana plants associated with the fungus were significantly affected by high disease severity and symptoms index (external leaves and internal rhizome), a high infection percentage of Fusarium wilt (%), dropping off of leaves as well as rotting of the root. Meanwhile, it was observed that the application of extract significantly improved the crop height, stem diameter, root size and distribution (root surface area, root diameter, and root volume), root–shoot ratio, as well as the soil physicochemical properties (CEC, N, p, K, Ca, and Mg), which enhanced resistance to Fusarium wilt diseases. We conclude that the application of NLE solution promotes better growth of Cavendish banana plants, soil physicochemical properties, and resistance to Fusarium wilt infection.

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 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.

Differential Root Morphology between Metallicolous and Non-Metallicolous Populations of Rumex japonicus under Copper Stress

2013 ◽  
Vol 726-731 ◽  
pp. 81-84
Author(s):  
Wu Xing Huang ◽  
Cong Ren ◽  
Jing Qing Gao
Keyword(s):  
Root Morphology ◽  
Root Surface ◽  
Root Diameter ◽  
Copper Stress ◽  
Shoot Biomass ◽  
Root Surface Area ◽  
Cu Stress ◽  
Root Shoot Ratio ◽  
Rumex Japonicus ◽  
Two Populations

Two Rumex japonicus populations, one from copper (Cu) mine and the other from uncontaminated site, were studied for root morphology and biomass under Cu stress. Main root length and number of tips of the two populations were both significantly inhibited by Cu treatments. However, those of metallicolous population (MP) were higher than non-metallicolous population (NMP) under Cu stress. Cu treatments significantly inhibited root surface area in NMP while MP showed little difference from control. Cu treatments inhibited average root diameter and root/shoot ratio in NMP, but those in MP were significantly higher than control. Cu treatments significantly inhibited shoot biomass and root biomass in NMP. These results suggested that more assimilates allocated to root and the average root diameter increased under Cu stress to form a greater and stronger root might be partly reasons why R. japonicus can colonize the Cu enriched soils.

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.

Root morphological characteristics of host species having distinct mycorrhizal dependency

1991 ◽  
Vol 69 (3) ◽  
pp. 671-676 ◽  
Author(s):  
A. Manjunath ◽  
M. Habte
Keyword(s):  
Root Hair ◽  
Morphological Characteristics ◽  
Root Surface ◽  
P Uptake ◽  
Root Diameter ◽  
Root Surface Area ◽  
Root Mass ◽  
Hair Length ◽  
Mycorrhizal Dependency ◽  
Root Characteristics

Greenhouse and growth chamber investigations were undertaken using selected Leucaena and Sesbania species to determine the extent to which root morphological characteristics and rhizosphere acid production could explain differences in mycorrhizal dependency of host plants. Compared with the moderately to very highly mycorrhizal-dependent Leucaena species, the marginally to moderately dependent Sesbania species were characterized by higher root mass, higher root density, higher root surface area, higher root length, smaller root diameter, higher percentage of root hair incidence, higher shoot to root ratio, and higher total P uptake. The two groups of species were not consistently different from each other with respect to mycorrhizal colonization level, root hair diameter, root hair length, P uptake per unit root surface area, and acid production in agar media. A stepwise regression model in which mycorrhizal dependency (MD) was used as the dependent variable and root characteristics as independent variables suggested that root mass, root hair length, root diameter, root density, and root hair incidence were important determinants of MD, with root mass accounting for 65.5% of the variability. The results suggest that differences in the mycorrhizal dependency of host species can be largely predicted from root characteristics data. Key words: Brassica, Leucaena, Sesbania, P uptake, root hair, root mass.

Carbon and nitrogen allocation patterns of Douglas-fir seedlings fertilized with nitrogen in autumn. II. Field performance

1986 ◽  
Vol 16 (5) ◽  
pp. 903-909 ◽  
Author(s):  
H. A. Margolis ◽  
R. H. Waring
Keyword(s):  
Free Amino ◽  
Shoot Growth ◽  
Field Performance ◽  
Growing Season ◽  
Frost Damage ◽  
Douglas Fir ◽  
Summer Drought ◽  
Tree Roots ◽  
Relative Growth ◽  
Relative Growth Rates

October-fertilized and unfertilized 2-0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were outplanted the following February. Half of each planting block was seeded with grass to induce water stress during the typical summer drought. Sucrose was applied to soil around each seedling to limit availability of nitrogen to tree roots. Fertilized seedlings broke bud 9–10 days earlier, produced more shoot growth, and, as shown in later harvests, had higher relative growth rates than unfertilized seedlings. However, initial differences in growth response were due primarily to the earlier budbreak. Seedlings growing with grass had predawn water potentials of −1.5 MPa by early August; by September 3, unfertilized seedlings growing with grass were significantly more stressed than any others. Although free amino acid and total nitrogen concentrations were higher in fertilized than unfertilized seedlings when planted, they became equal by the end of one growing season. However, fertilized seedlings contained more free amino acids and nitrogen because of their greater size. Grass competition affected both seedling nitrogen and carbohydrate chemistry. After one growing season, fertilized seedlings had greater height increment, shoot growth, leaf area, relative growth rate, and production per unit nitrogen. Although autumn fertilization benefited these Douglas-fir seedlings, negative effects could result from carbohydrate depletion because of increased respiration or from frost damage because of earlier budbreak.

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