scholarly journals Early Growth and Development of Pawpaw [Asimina triloba (L.) Dunal] Seedlings in the Greenhouse as Influenced by Shade and Root-zone Modification

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 532E-533
Author(s):  
Desmond R. Layne ◽  
L.N. Peters
Keyword(s):  
Growth And Development ◽  
Lateral Root ◽  
Root Zone ◽  
Plant Biomass ◽  
Lateral Roots ◽  
Incident Light ◽  
Light Level ◽  
Control Treatment ◽  
Whole Plant ◽  
Split Plot

This experiment was designed to determine the optimal light level for growing pawpaw seedlings in the greenhouse. In addition, we wanted to determine if modifying the root-zone would positively impact pawpaw seedling growth and development. Experimental treatments were imposed from seed sowing until the plants were destructively harvested. The experimental design was a split-plot, where blocking was done by position in the greenhouse. The main plot of the experiment was shade. This was accomplished by growing seedlings under a wooden frame covered with shadecloth to reduce incident light intensity received by the plant by 30%, 55%, 80%, or 95%. The control treatment was 0% shade or ambient greenhouse light level. The split-plot was root-zone modification. Half of all growing containers were untreated (control) while the other half were painted with SpinOut™, a commercially available product used to reduce root spiraling in nursery containers. There were 40 replicate seedlings per experimental treatment combination per block. Seedling shoot length and unfolded leaf number was recorded twice a week from seedling emergence until destructive harvest. Whole-plant leaf area was also determined. Leaves, stems, and tap and lateral roots were separated and dried to determine biomass partitioned to the respective organs. Up to 55% shade did not significantly reduce whole-plant biomass, while plants at 80% and 95% shade were stunted. Shade in the greenhouse is not required as was previously thought. Specific leaf mass and lateral root mass decreased as shade increased. Neither tap or lateral root dry weights were significantly affected by root-zone modification. New recommendations for container production of pawpaws in the greenhouse will be discussed.

scholarly journals Mitigation of Nickel Toxicity and Growth Promotion in Sesame through the Application of a Bacterial Endophyte and Zeolite in Nickel Contaminated Soil

2020 ◽  
Vol 17 (23) ◽  
pp. 8859 ◽  
Author(s):  
Muhammad Naveed ◽  
Syeda Sosan Bukhari ◽  
Adnan Mustafa ◽  
Allah Ditta ◽  
Saud Alamri ◽  
...  
Keyword(s):  
Plant Growth ◽  
Contaminated Soil ◽  
Root Zone ◽  
Plant Biomass ◽  
Growth Promotion ◽  
Research Work ◽  
Control Treatment ◽  
Soil Conditions ◽  
Combined Application ◽  
Bioavailable Fraction

Nickel (Ni) bioavailable fraction in the soil is of utmost importance because of its involvement in plant growth and environmental feedbacks. High concentrations of Ni in the soil environment, especially in the root zone, may retard plant growth that ultimately results in reduced plant biomass and yield. However, endophytic microorganisms have great potential to reduce the toxicity of Ni, especially when applied together with zeolite. The present research work was conducted to evaluate the potential effects of an endophytic bacterium Caulobacter sp. MN13 in combination with zeolite on the physiology, growth, quality, and yield of sesame plant under normal and Ni stressed soil conditions through possible reduction of Ni uptake. Surface sterilized sesame seeds were sown in pots filled with artificially Ni contaminated soil amended with zeolite. Results revealed that plant agronomic attributes such as shoot root dry weight, total number of pods, and 1000-grains weight were increased by 41, 45, 54, and 65%, respectively, over control treatment, with combined application of bacteria and zeolite in Ni contaminated soil. In comparison to control, the gaseous exchange parameters (CO2 assimilation rate, transpiration rate, stomatal- sub-stomatal conductance, chlorophyll content, and vapor pressure) were significantly enhanced by co-application of bacteria and zeolite ranging from 20 to 49% under Ni stress. Moreover, the combined utilization of bacteria and zeolite considerably improved water relations of sesame plant, in terms of relative water content (RWC) and relative membrane permeability (RMP) along with improvement in biochemical components (protein, ash, crude fiber, fat), and micronutrients in normal as well as in Ni contaminated soil. Moreover, the same treatment modulated the Ni-stress in plants through improvement in antioxidant enzymes (AEs) activities along with improved Ni concentration in the soil and different plant tissues. Correlation and principal component analysis (PCA) further revealed that combined application of metal-tolerant bacterium Caulobacter sp. MN13 and zeolite is the most influential strategy in alleviating Ni-induced stress and subsequent improvement in growth, yield, and physio-biochemical attributes of sesame plant.

scholarly journals Effects of phosphorus, indolebutyric acid and naphthylphthalamic acid on the lateral root growth of Poncirus trifoliata

2021 ◽  
Vol 8 (9) ◽  
pp. 13-16
Author(s):  
Gong Tian-zhi ◽  
Zhang De-jian
Keyword(s):  
Lateral Root ◽  
Plant Biomass ◽  
Poncirus Trifoliata ◽  
Control Treatment ◽  
Auxin Signaling ◽  
Trifoliate Orange ◽  
Indolebutyric Acid ◽  
Auxin Signaling Pathway ◽  
Key Factor ◽  
Naphthylphthalamic Acid

To explore the influence of phosphorus (P), indolebutyric acid (IBA, Auxin) and Naphthylphthalamic acid (NPA, Auxin transport inhibitor) on plant lateral root (LR) formation, Poncirus trifoliata seedlings at two P levels, low P (LP) and control treatment (CK), which was applied with IBA and NPA, and the regulative effects of P level, IBA and NPA on LR formation of trifoliate orange were investigated. The results showed that LP level significantly reduced the plant biomass, LR number and length. NPA significantly decreased the plant biomass, LR number and length, while IBA did not significantly influence these parameters. These data suggested that auxin signaling pathway could be involved in the regulation of P level on LR formation, and the auxin transportation should be the key factor in LR formation of trifoliate orange.

scholarly journals Induction of Lateral Root Structure Formation on Petunia Roots: A Novel Effect of GMI1000 Ralstonia solanacearum Infection Impaired in Hrp Mutants

2006 ◽  
Vol 19 (6) ◽  
pp. 597-606 ◽  
Author(s):  
Lena Zolobowska ◽  
Frédérique Van Gijsegem
Keyword(s):  
Ralstonia Solanacearum ◽  
Lateral Root ◽  
Plant Pathogens ◽  
Lateral Roots ◽  
Root Tips ◽  
Whole Plant ◽  
Systemic Spread ◽  
Mutant Strains ◽  
Architecture Development ◽  
Lateral Structures

Ralstonia solanacearum is a soilborne plant pathogen that invades its host via roots. As in many gram-negative bacterial plant pathogens, the R. solanacearum Hrp type III secretion system is essential for interactions of the bacterium with plants; however, the related mechanisms involved in disease expression are largely unknown. In this work, we examined the effects of infection by R. solanacearum GMI1000 and Hrp mutants on the root system of petunia plants. Both the wild-type and mutant strains disturbed the petunia root architecture development by inhibiting lateral root elongation and provoking swelling of the root tips. In addition, GMI100 but not the Hrp mutants induced the formation of new root lateral structures (RLS). This ability is shared by other, but not all, R. solanacearum strains tested. Like lateral roots, these new structures arise from divisions of pericycle founder cells which, nevertheless, exhibit an abnormal morphology. These RLS are efficient colonization sites allowing extensive bacterial multiplication. However, they are not required for the bacterial vascular invasion that leads to the systemic spread of the bacterium through the whole plant, indicating that, instead, they might play a role in the rhizosphere-related stages of the R. solanacearum life cycle.

scholarly journals The Effect of Deficit Irrigation Strategies on the Efficiency From Plant to Essential Oil Production in Peppermint (Mentha piperita L.)

2021 ◽  
Vol 3 ◽  
Author(s):  
Ali Akbarzadeh ◽  
Ali Shahnazari
Keyword(s):  
Essential Oil ◽  
Deficit Irrigation ◽  
Root Zone ◽  
Water Productivity ◽  
Control Treatment ◽  
Mentha Piperita ◽  
Regulated Deficit Irrigation ◽  
Aerial Parts ◽  
Whole Plant ◽  
Essential Oil Yield

The effect of deficit irrigation on water productivity in the water supply and utilization chain has been computed, employing a systematic and quantitative approach. By applying such an investigation, weaknesses and strengths of deficit irrigation strategies could be revealed, and actions and measures could be implemented to improve water productivity as much as possible. The peppermint plants were subjected to regulated deficit irrigation (RDI) and partial root-zone drying (PRD). Peppermint was cultivated under full irrigation (FI, control) and RDI treatments including RDI85, RDI70, RDI55, and RDI40, receiving 85, 70, 55, and 40% of FI treatment, respectively; PRD techniques including PRD70, PRD55, and PRD40, receiving 70, 55, and 40% of FI treatment in one side of the root-zone at each irrigation event, respectively during two cutting seasons. There was no significant improvement in leaves weight and dried yield step by applying deficit irrigation treatments. Leaves and aerial parts from the whole plant and dried yield as the main source of essential oil had the weakest function, which should be optimized to adjust and gain more efficiency. In the essential oil yield step, as a final procedure, the highest improvements were observed in PRD55 treatment with 90% improvement in efficiency compared to control treatment. According to the results and calculating water productivity, PRD55 treatment improved water productivity by 179% compared to the control treatment. Two-way ANOVA analysis, between deficit volume and the deficit applying method, showed that total water productivity was affected (increased) significantly by the deficit applying method. This implies the contribution of the PRD technique to enhance more signals than RDI-based signals, which resulted in more improvements in secondary metabolism production in peppermint.

Effects of Phosphorus on Growth and Development of Soybean Seedlings

2022 ◽  
Vol 905 ◽  
pp. 353-358
Author(s):  
Zi Xin Liao ◽  
Xiao Hao Li ◽  
Ying Bin Xue ◽  
Nai De Yang ◽  
Zheng Wei Wu ◽  
...  
Keyword(s):  
Root Length ◽  
Growth And Development ◽  
Lateral Root ◽  
Early Stage ◽  
Phosphorus Deficiency ◽  
Lateral Roots ◽  
Physiological Effect ◽  
Phosphorus Concentration ◽  
Basic Study ◽  
Soybean Seedlings

Soybean seedlings were treated with different phosphorus (P) concentrations for 20 days to investigate their growth and development. The root growth and development of soybean seedlings was the best when the concentration of phosphorus was 250 μmol/L. After 20 days of cultivation at this concentration, the roots of soybean seedlings were developed, indicating that the main root length, lateral root length, and the number of lateral root was the best among all treatments, and the number of lateral roots was quite a few. In addition, when the concentration of P was at 250 μmol/L, it had a better promotion effect on the plant height of soybean seedlings, and could significantly enhance the development of soybean seedlings. Moreover, the growth of soybean seedlings would be inhibited at the condition of phosphorus deficiency or excessive phosphorus. In this experiment, the growth indexes of soybean seedlings were compared between four treatments of phosphorus concentration, so as to make a basic study on the physiological effect of soybean on phosphorus in early stage.

scholarly journals First Report of Phytophthora cryptogea in Walnut Stands in Italy

Plant Disease ◽  
2002 ◽  
Vol 86 (3) ◽  
pp. 328-328 ◽  
Author(s):  
A. M. Vettraino ◽  
A. Belisario ◽  
M. Maccaroni ◽  
N. Anselmi ◽  
A. Vannini
Keyword(s):  
Lateral Root ◽  
Root Zone ◽  
Lateral Roots ◽  
Juglans Regia ◽  
Central Italy ◽  
The United States ◽  
Selective Medium ◽  
Northern Italy ◽  
Internal Transcribed Spacer Region ◽  
First Report

English (Persian) walnut (Juglans regia L.) is among the most widely cultivated species in pure and mixed plantations of broadleaved trees in Italy. A decline of walnut of increasing occurrence has been reported recently in new plantations in central and northern Italy. Symptoms of the decline were typically characterized by yellowing of the foliage, defoliation, and plant death. Dark, flame-shaped necroses were often present at the collar. Phytophthora cactorum, P. cambivora, and P. cinnamomi were among the species associated with necrotic tissues of the collar and main roots (1). Furthermore, a Phytophthora sp. was isolated from soil removed from the lateral root zone of 6 of 15 declining trees in 3 walnut plantations, 2 in northern Italy and 1 in central Italy. Isolations were made by baiting with Rhododendron leaves and plating on PARBhy selective medium (3). The species isolated was identified as P. cryptogea on the basis of morphological and cultural characteristics (2). All isolates produced oval to obpyriform, nonpapillate sporangia and were mating type A2. Identification of the isolates was confirmed by comparing the restriction fragment length polymorphism patterns of the internal transcribed spacer region of ribosomal DNA with those obtained from previously identified Phytophthora species. Pathogenicity tests on potted 2-year-old walnut seedlings were conducted using two isolates of P. cryptogea. Inoculum was prepared by growing isolates on sterilized millet seeds added to soil at 2.5% (wt/vol). Sporulation was induced by 24-h flooding of the soil. Symptoms were assessed 1 month after inoculation. Ten uninoculated seedlings were used as controls. Inoculated seedlings showed no symptoms on the tap root, but there were extensive necroses of lateral roots ranging from 14 to 75% (average 38.6 ± 6.7 SE) of total lateral root (dry weight) compared with values of 0 to 11% (average 3 ± 1.5 SE) for uninoculated seedlings. P. cryptogea was easily reisolated from infected lateral roots and from the soil of inoculated pots. The inoculation trials confirmed P. cryptogea as a feeder-root pathogen of walnut in Italy. To our knowledge, this is the first report of P. cryptogea on English walnut in Italy. This species often has been associated with walnut decline in the United States (2) and on other woody plants in Italy (3). References: (1) A. Belisario et al. Petria 11:127, 2001. (2) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Association, St. Paul, MN, 1996. (3) A. M. Vettraino et al. Plant Pathol. 50:90, 2001.

Effect of Root-zone Temperature on Strawberry Growth and Development

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 460b-460
Author(s):  
Melita Marion Biela ◽  
Gail R. Nonnecke ◽  
William R. Graves ◽  
Harry T. Horner
Keyword(s):  
Growth And Development ◽  
Root Zone ◽  
Leaf Growth ◽  
Block Design ◽  
Dry Weight ◽  
Root Zone Temperature ◽  
Whole Plant ◽  
Weight Analysis ◽  
Vegetative And Reproductive Growth ◽  
Zone Temperature

Root-zone temperature (RZT) effects were studied to determine physiological changes on whole-plant and microscopic levels of strawberry (Fragaria ×ananassa) growth and development. A greenhouse experiment was conducted in 1997 with `Tristar' day-neutral strawberry using a randomized complete-block design with three RZT treatments (23, 29, and 35 °C) and four replications. The total number of flowers was less in plants subjected to 35 °C. Total weight of fruit yield was highest at 29 °C and least at 23 °C, due possibly to later fruit development. Fresh weight was highest in plants grown at 23 and 29 °C. Dry weight analysis showed that root and leaf growth were inhibited at 35 °C. Throughout the duration of the experiment, transpiration rates were lower in plants subjected to 35 °C. In general, plants grown under RZT of 29 °C had more optimal vegetative and reproductive growth than those grown under 23 and 35 °C.

scholarly journals Response of Root Growth and Development to Nitrogen and Potassium Deficiency as well as microRNA-Mediated Mechanism in Peanut (Arachis hypogaea L.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Lijie Li ◽  
Qian Li ◽  
Kyle E. Davis ◽  
Caitlin Patterson ◽  
Sando Oo ◽  
...  
Keyword(s):  
Root Growth ◽  
Arachis Hypogaea ◽  
Root Length ◽  
Growth And Development ◽  
Lateral Root ◽  
Lateral Roots ◽  
Primary Root ◽  
K Deficiency ◽  
N Deficiency ◽  
Root Growth And Development

The mechanism of miRNA-mediated root growth and development in response to nutrient deficiency in peanut (Arachis hypogaea L.) is still unclear. In the present study, we found that both nitrogen (N) and potassium (K) deficiency resulted in a significant reduction in plant growth, as indicated by the significantly decreased dry weight of both shoot and root tissues under N or K deficiency. Both N and K deficiency significantly reduced the root length, root surface area, root volume, root vitality, and weakened root respiration, as indicated by the reduced O2 consuming rate. N deficiency significantly decreased primary root length and lateral root number, which might be associated with the upregulation of miR160, miR167, miR393, and miR396, and the downregulation of AFB3 and GRF. The primary and lateral root responses to K deficiency were opposite to that of the N deficiency condition. The upregulated miR156, miR390, NAC4, ARF2, and AFB3, and the downregulated miR160, miR164, miR393, and SPL10 may have contributed to the growth of primary roots and lateral roots under K deficiency. Overall, roots responded differently to the N or K deficiency stresses in peanuts, potentially due to the miRNA-mediated pathway and mechanism.

Indolebutyric acid and ectomycorrhizal inoculation increase lateral root initiation and development of container-grown black oak seedlings

1987 ◽  
Vol 17 (1) ◽  
pp. 36-39 ◽  
Author(s):  
C. M. Baser ◽  
H. E. Garrett ◽  
R. J. Mitchell ◽  
G. S. Cox ◽  
C. J. Starbuck
Keyword(s):  
Growth Medium ◽  
Growth And Development ◽  
Lateral Root ◽  
Acid Treatment ◽  
Lateral Roots ◽  
Root Initiation ◽  
Indolebutyric Acid ◽  
Lateral Root Initiation ◽  
Black Oak ◽  
Oak Seedlings

Containerized black oak seedlings in which the growth medium was inoculated with Pisolithustinctorius (Pers.) Coker Couch or left uninoculated were grown for 16 weeks with or without a polyacrylic starch containing 1000 μg indolebutyric acid per gram mixed throughout the growth medium. Seedlings treated with indolebutyric acid developed more than twice as many lateral roots as control seedlings which did not receive indolebutyric acid. Indolebutyric acid reduced the percentage of primary laterals colonized by P. tinctorius; however, the total number of colonized lateral roots was not affected. The combination of ectomycorrhizal inoculation with the indolebutyric acid treatment significantly increased the growth and development of black oak seedlings.

scholarly journals 342 Shading Influences the Growth and Development of Pawpaw Seedlings Grown Outside

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 502B-502
Author(s):  
Kirk W. Pomper ◽  
Snake C. Jones ◽  
Eddie B. Reed
Keyword(s):  
Plant Biomass ◽  
Block Design ◽  
Incident Light ◽  
Experimental Treatment ◽  
Dry Weight ◽  
Light Level ◽  
Asimina Triloba ◽  
Leaf Chlorophyll ◽  
Randomized Block Design ◽  
Total Plant Biomass

In an effort to determine the optimal light level for growing pawpaw [Asimina triloba (L.) Dunal] seedlings outside, seedlings were germinated in a greenhouse until the two- to three-leaf stage, at which time they were placed outside and shade treatments were imposed that reduced incident light intensity by 30%, 55%, 80%, and 95%. Control seedlings were left unshaded outside. A randomized block design was used, with 20 replicate seedlings in each experimental treatment per block. Plants were destructively harvested 11 weeks after the start of the experiment. After 11 weeks, the height and number of leaves per seedling were about 35% higher with light to moderate shading (30%, 55%, and 80%) than in control (unshaded) seedlings. Shoot and leaf dry weights of seedlings grown in 30%, 55%, and 80% shade were almost 2-fold greater than control plants. Root dry weight of seedlings in 30% and 55% shade was 2-fold higher than in control plants. Total plant biomass was greatest in the 30%, 55%, and 80% shade treatments, about 2-fold higher than control plants. Total leaf area per seedling increased significantly with up to 80% shading. Seedlings growing under 95% shading had fewer and smaller leaves and reduced biomass production compared to control plants. There was a trend for shaded plants to display a higher leaf chlorophyll content than control plants. Overall, the best seedling growth was achieved in the 30% and 55% shade treatments outdoors.

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