scholarly journals Kenaf (Hibiscus cannabinus L.) Impact on Post-Germination Seedling Growth

2015 ◽  
Vol 7 (12) ◽  
pp. 91
Author(s):  
Charles L. Webber III ◽  
Paul M. White Jr ◽  
Dwight L. Myers ◽  
James W. Shrefler ◽  
Merritt J. Taylor
Keyword(s):  
Root Growth ◽  
Italian Ryegrass ◽  
Hibiscus Cannabinus ◽  
Green Bean ◽  
Hypocotyl Growth ◽  
Leaf Extracts ◽  
Radicle Growth ◽  
Redroot Pigweed ◽  
Mixed Response ◽  
The Impact

<p>The chemical interaction between plants, which is referred to as allelopathy, may result in the inhibition of plant growth and development. The objective of this research was to determine the impact of kenaf (<em>Hibiscus cannabinus</em> L.) plant extracts on the post-germination growth of five plant species. Four concentrations (0, 16.7, 33.3 and 66.7 g/L) of kenaf bark, core, and leaf extracts were applied to the germinated seeds of redroot pigweed (<em>Amaranthus retroflexus</em> L.), green bean (<em>Phaseolus vulgaris</em> L.), tomato (<em>Solanum lycopersicum </em>Mill.), cucumber (<em>Cucumis sativus</em> L.), and Italian ryegrass (<em>Lolium multiflorum</em> Lam.). After 7 days, the developing seedlings were measured to determine the length of their hypocotyls (mm) and radicles (mm), and the number of hair roots. Tomato, Italian ryegrass, and redroot pigweed followed similar negative trends in their responses to the extract source (kenaf bark, core, and leaves) and the impact of extract concentration, whereas, cucumber had a mixed response and green bean reacted positively to the kenaf extracts. Tomato was the most sensitive species tested across all kenaf extracts and concentrations, resulting in decreased hypocotyl, radicle, and root growth. Green bean exhibited no negative effects due to the kenaf extracts, but actually produced increased hypocotyl growth as a result of the kenaf bark, core, and leaf extracts. The kenaf extracts resulted in a mixed response for cucumber. The kenaf leaf and bark extract decreased cucumber radicle growth, whereas, the bark and core extracts increased hypocotyl growth. Italian ryegrass hypocotyl growth decreased across all extract sources (bark, core, and leaf), while the leaf extract also reduced root growth. All kenaf extracts reduced redroot pigweed radicle growth, while the core and leaf extracts reduced hypocotyl growth. The research demonstrated that kenaf leaf extracts were the most allelopathic and the hypocotyls were the most sensitive. Future research should isolate the chemicals responsible for both the negative and positive allelopathic impact on the various plant species, determine if the extracts will influence more mature plants, and pursue cultural practices to utilize these natural allelopathic materials to benefit crop production and limit weed competition.</p>

scholarly journals Allelopathic potential of Acacia pennata (L.) Willd. leaf extracts against the seedling growth of six test plants

2020 ◽  
Vol 48 (3) ◽  
pp. 1534-1542
Author(s):  
Ei H. KYAW ◽  
Hisashi KATO-NOGUCHI
Keyword(s):  
Root Growth ◽  
Plant Species ◽  
Seedling Growth ◽  
Phleum Pratense ◽  
Italian Ryegrass ◽  
Test Plant ◽  
Allelopathic Effect ◽  
Leaf Extracts ◽  
Isolation And Identification ◽  
Allelopathic Potential

Acacia pennata (L.) Willd (Mimosaceae), a woody climbing plant, is used as a traditional medicinal plant in the South and Southeast Asia regions and has been documented to have various pharmacological effects. However, the allelopathy of this plant still remains unclear. Thus, the allelopathic potential of A. pennata leaf extracts was examined against the seedling growth of dicot plants [alfalfa (Medicago sativa L.), cress (Lepidium sativum L.), and lettuce (Lactuca sativa L.)] and monocot plants [barnyard grass (Echinochloa crus-galli (L.) Beauv.), Italian ryegrass (Lolium multiflorum Lam.), and timothy (Phleum pratense L.)] at six different concentrations. The results showed that the A. pennata leaf extracts inhibited the seedling growth of all the test plant species at concentrations ≥3 mg dry weight (D.W.) equivalent extract mL-1. The inhibitory activity of the extracts against both shoot and root growth varied with concentration and tested plants. The concentrations required for 50% inhibition of the test plant shoots and roots were 1.5-16.1 and 1.4-8.6 mg D.W. equivalent extract mL-1, respectively. The root growth of all the test plant species was more sensitive to the extracts than their shoot growth, except alfalfa. The results of the present study indicate that the A. pennata leaf extracts may have allelopathic potential and may contain allelopathic substances. Therefore, further studies are required for isolation and identification of the growth inhibitory substances which are responsible for the allelopathic effect of A. pennata.

scholarly journals Phytotoxic Activity and Identification of Phytotoxic Substances from Schumannianthus dichotomus

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 102 ◽  
Author(s):  
Md. Mahfuzur Rob ◽  
Kawsar Hossen ◽  
Arihiro Iwasaki ◽  
Kiyotake Suenaga ◽  
Hisashi Kato-Noguchi
Keyword(s):  
Root Growth ◽  
Syringic Acid ◽  
Italian Ryegrass ◽  
Dependent Manner ◽  
Leaf Extracts ◽  
Concentration Dependent Manner ◽  
Crop Fields ◽  
Phytotoxic Activity ◽  
Shoot And Root Growth ◽  
Methyl Syringate

The phytotoxic potential of plants and their constituents against other plants is being increasingly investigated as a possible alternative to synthetic herbicides to control weeds in crop fields. In this study, we explored the phytotoxicity and phytotoxic substances of Schumannianthus dichotomus, a perennial wetland shrub native to Bangladesh, India, and Myanmar. Leaf extracts of S. dichotomus exerted strong phytotoxicity against two dicot species, alfalfa and cress, and two monocot species, barnyard grass and Italian ryegrass. A bioassay-driven purification process yielded two phenolic derivatives, syringic acid and methyl syringate. Both constituents significantly inhibited the growth of cress and Italian ryegrass in a concentration-dependent manner. The concentrations required for 50% growth inhibition (I50 value) of the shoot and root growth of cress were 75.8 and 61.3 μM, respectively, for syringic acid, compared with 43.2 and 31.5 μM, respectively, for methyl syringate. Similarly, to suppress the shoot and root growth of Italian rye grass, a greater amount of syringic acid (I50 = 213.7 and 175.9 μM) was needed than methyl syringate (I50 = 140.4 to 130.8 μM). Methyl syringate showed higher phytotoxic potential than syringic acid, and cress showed higher sensitivity to both substances. This study is the first to report on the phytotoxic potential of S. dichotomus and to identify phytotoxic substances from this plant material.

Chemical Composition and Antimicrobial Activity of Bark and Leaf Extracts of Cupressus sempervirens and Juniperus phoenicea Grown in Al- Jabel Al-Akhdar Region, Libya

2019 ◽  
Vol 9 (4) ◽  
pp. 268-279
Author(s):  
Mohamed E.I. Badawy ◽  
Ibrahim E.A. Kherallah ◽  
Ahmed S.O. Mohareb ◽  
Mohamed. Z.M. Salem ◽  
Hameda A. Yousef
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Sea Level ◽  
Plant Extracts ◽  
Complex Mixture ◽  
Biologically Active ◽  
Cupressus Sempervirens ◽  
Leaf Extracts ◽  
Juniperus Phoenicea ◽  
The Impact

Background:Plant extracts are important products in the world and have been widely used for isolation of important biologically active products. Because of their significant environmental impact, extensive research has been explored to determine the antimicrobial activity of plant extracts.Methods:Acetone extracts of the bark and leaf of Cupressus sempervirens and Juniperus phoenicea, collected from three different altitudes (125, 391, and 851 m high of sea level) at Al- Jabel Al-Akhdar area, Libya were obtained and analyzed by GC/MS. The antimicrobial activity of the extracts was further evaluated against plant bacteria Rhizobium radiobacter, Erwinia carotovora, Rhodococcus fascians and Ralstonia solanacearum and fungus Botrytis cinerea.Results:The impact of the altitude from the sea level on the quantity and chemical constituents of the extracts was investigated. The yield was largely dependent on tree species and the highest yield (6.50%) was obtained with C. sempervirens L bark of altitude III (851 m of the sea level), while the lowest (1.17%) was obtained with the leaf extract of C. sempervirens L from altitude I (125 m). The chemical composition analyzed by GC/MS confirmed that the leaf extracts of C. sempervirens and J. phoenicea contained a complex mixture of monoterpene hydrocarbons, sesquiterpenes, diterpenes, diterpenoids, terpenophenolic, steroids and phthalates. However, the bark extracts of both trees contained a mixture of sesquiterpenes, diterpenes, diterpenoids, terpenophenolics, phthalates, retinol and steroids. These constituents revealed some variability among the extracts displaying the highest interesting chemotype of totarol (terpenophenolic) in all extracts (14.63-78.19% of the total extract). The extracts displayed a noteworthy antifungal potency with varying degrees of inhibition of growth with EC50 values ranged from 78.50 to 206.90 mg/L. The extracts obtained from the leaves of C. sempervirens showed that the highest inhibitory activity was obtained with the extract of altitude II (391 m) with MIC 565, 510, 380 and 710 mg/L against E. carotovora, R. fascians, and R. radiobacter and R. solanacearum, respectively.Conclusion:Based on antimicrobial activity, raw plant extracts can be a cost-effective way to protect crops from microbial pathogens. Because plant extracts contain several antimicrobial compounds, the development of resistant pathogens can be delayed.

scholarly journals The Arabidopsis Root Tip (Phospho)Proteomes at Growth-Promoting versus Growth-Repressing Conditions Reveal Novel Root Growth Regulators

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1665
Author(s):  
Natalia Nikonorova ◽  
Evan Murphy ◽  
Cassio Flavio Fonseca de Lima ◽  
Shanshuo Zhu ◽  
Brigitte van de Cotte ◽  
...  
Keyword(s):  
Cell Wall ◽  
Root Growth ◽  
Growth Regulators ◽  
Growth Regulation ◽  
Phosphorylation Site ◽  
Primary Root ◽  
Root Tip ◽  
Arabidopsis Root ◽  
Growth Promoting ◽  
The Impact

Auxin plays a dual role in growth regulation and, depending on the tissue and concentration of the hormone, it can either promote or inhibit division and expansion processes in plants. Recent studies have revealed that, beyond transcriptional reprogramming, alternative auxin-controlled mechanisms regulate root growth. Here, we explored the impact of different concentrations of the synthetic auxin NAA that establish growth-promoting and -repressing conditions on the root tip proteome and phosphoproteome, generating a unique resource. From the phosphoproteome data, we pinpointed (novel) growth regulators, such as the RALF34-THE1 module. Our results, together with previously published studies, suggest that auxin, H+-ATPases, cell wall modifications and cell wall sensing receptor-like kinases are tightly embedded in a pathway regulating cell elongation. Furthermore, our study assigned a novel role to MKK2 as a regulator of primary root growth and a (potential) regulator of auxin biosynthesis and signalling, and suggests the importance of the MKK2 Thr31 phosphorylation site for growth regulation in the Arabidopsis root tip.

Effects of organic matter and time of incorporation on root development of tropical maize seedlings

2008 ◽  
Vol 56 (2) ◽  
pp. 169-178
Author(s):  
U. Sangakkara ◽  
S. Nissanka ◽  
P. Stamp
Keyword(s):  
Organic Matter ◽  
Root Growth ◽  
Rice Straw ◽  
Organic Materials ◽  
Gliricidia Sepium ◽  
Quality Parameters ◽  
Control Treatment ◽  
Poor Growth ◽  
Time Of Application ◽  
The Impact

Smallholders in the tropics add different organic materials to their crops at different times, based on the availability of materials and labour. However, the time of application could have an effect on the establishment and early growth of crops, especially their root systems, which has not yet been clearly identified. This paper presents the results of a study conducted under greenhouse conditions using soils from a field treated with three organic materials at 4 or 2 weeks before or at the planting of maize seeds, corresponding to the times that tropical smallholders apply these materials. The organic materials used were leaves of Gliricidia sepium and Tithonia diversifolia or rice straw, incorporated at a rate equivalent to 6 Mt ha −1 . A control treatment where no organic matter was added was used for comparison. The impact of the treatments on soil properties at the planting of maize seed and detailed root analysis based on root lengths were carried out until the last growth stage (V4). The addition of organic matter improved the soil characteristics, and the impact of adding Gliricidia leaves was most pronounced when incorporated 2 weeks before planting. The benefits of leaves of Tithonia or rice straw on soil quality parameters were clearly evident when added 4 weeks before planting. Organic matter enhanced the root number, root length, root growth rate and branching indices. All the organic materials suppressed the growth of maize roots when applied at planting, suggesting the existence of allelopathic effects, which could result in poor growth. The most benefits in terms of root growth were observed with Tithonia .

scholarly journals Influence of hydroxyurea on the course of germination and growth of rape (Brasica napus L.) seedlings

2015 ◽  
Vol 47 (1–2) ◽  
pp. 131-141 ◽  
Author(s):  
M. Kuraś ◽  
H. Teleżyński
Keyword(s):  
Mitochondrial Dna ◽  
Root Growth ◽  
Dna Synthesis ◽  
Elongation Growth ◽  
Complete Inhibition ◽  
Hypocotyl Growth ◽  
Prolonged Incubation ◽  
Inhibition Of Growth ◽  
Germination And Growth ◽  
Mitochondrial Dna Synthesis

The effects of continuous incubation in hydroxyurea (HU) solutions (0.2, 0.4, 0.8 mg/ml) on germination of rape seeds and growth of young seedling axes were studied during 132 hours from initial soaking. Germination turned out to be unaffected by the treatment. Root growth was first increasingly inhibited by the HU concentration tested, but after prolonged incubation a complete arrest of the root growth was noted at all HU concentrations. The elongation growth of hypocotyls was found to be stimulated by a HU 0.2 mg/ml concentration while it was markedly suppressed by 0.4 mg/ml, and completely arrested by 0.8 mg/ml Inhibition of growth of the upright hypocotyl part at higher HU concentration was found to be accompanied by the unbending of the hooked under-cotyledonary part. It is suggested that inhibition of nuclear endomitotic DNA synthesis In elongating hypocotyl cells, suppresses only partially their growth, whereas a complete inhibition of the hypocotyl growth results from arrest of the mitochondrial DNA synthesis.

scholarly journals Elevated CO2 Concentrations and Water Stress Affect the Ability of Italian Ryegrass to Remediate Herbicides and Enhance its Allelopathic Effect

2019 ◽  
Vol 37 ◽  
Author(s):  
L.P. SILVEIRA ◽  
A.R. FEIJÓ ◽  
C. BENETTI ◽  
J.P. REFATTI ◽  
M.V. FIPKE ◽  
...  
Keyword(s):  
Water Stress ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Italian Ryegrass ◽  
Allelopathic Effect ◽  
Irrigated Rice ◽  
Allelopathic Potential ◽  
Co2 Concentrations ◽  
Temporal Persistence ◽  
The Impact

ABSTRACT: The long temporal persistence of select herbicides negatively impacts crops sown in succession to irrigated rice. One way to reduce these compounds in the soil over time is through phytoremediation. However, elevated CO2 concentrations may interfere with the phytoremediation process. Another consequence of climate change is the production of allelopathic compounds by forage species used as remedial agents. This study aimed to evaluate the impact of elevated CO2 concentration and drought stress on the remediation of soil samples contaminated with imazapyr + imazapic herbicides by Italian ryegrass and any subsequential affect on the allelopathic effect of this species. We report that the increasing CO2 decreased the phytoremediation potential of ryegrass. Water stress combined with a CO2 concentration of 700 µmol mol-1 caused increased allelopathy. Overall, these are the first data to indicate a significant effect of higher CO2 levels with respect to both phytoremediation efficacy and allelopathic potential of the plant species used in phytoremediation.

scholarly journals Phytotoxic effects of Cerbera manghas L. leaf extracts on seedling elongation of four monocot and four dicot test species

2017 ◽  
Vol 70 (3) ◽  
Author(s):  
Ichsan Nurul Bari ◽  
Hisashi Kato-Noguchi
Keyword(s):  
Weed Management ◽  
Dry Weight ◽  
Phleum Pratense ◽  
Italian Ryegrass ◽  
Lepidium Sativum ◽  
Leaf Extracts ◽  
Isolation And Identification ◽  
Test Species ◽  
Phytotoxic Effects ◽  
Cerbera Manghas

Exploration of allelochemicals with phytotoxic effects is intended to minimize a current dependency on synthetic herbicides in weed management. Several allelochemicals from the tropical tree <em>Cerbera manghas</em> (sea mango) have been reported as termiticides and bactericides. The present study investigated possible phytotoxic effects of <em>C. manghas</em> leaf extracts under laboratory conditions. Four monocots: barnyard grass (<em>Echinochloa crus-galli</em>), foxtail fescue (<em>Vulpia myuros</em>), Italian ryegrass (<em>Lolium multiflorum</em>), and timothy (<em>Phleum pratense</em>) and four dicots: alfalfa (<em>Medicago sativa</em>), garden cress (<em>Lepidium sativum</em>), lettuce (<em>Lactuca sativa</em>), and rapeseed (<em>Brassica napus</em>) were used as test species. Elongation of both shoots and roots of seedlings was measured to assess any phytotoxic effects. The results showed that the sensitivities of shoots and roots were different between the test species, and the inhibition of seedling elongation significantly increased with increasing concentration of leaf extracts of <em>C. manghas</em> for all the test species. The IC<sub>50</sub> (50% inhibitory concentration) values showed that 8.50–32.30 and 4.26–34.67 mg dry weight equivalent extract mL<sup>−1</sup> of <em>C. manghas</em> inhibited seedling elongation by 50%, for shoots and roots respectively. Isolation and identification of the phytotoxic substances from <em>C. manghas</em> are suggested for future investigation.

Root Growth of Neighboring Maize and Weeds Studied with Minirhizotrons

Weed Science ◽  
2013 ◽  
Vol 61 (2) ◽  
pp. 319-327 ◽  
Author(s):  
Deborah Britschgi ◽  
Peter Stamp ◽  
Juan M. Herrera
Keyword(s):  
Root Growth ◽  
Surface Area ◽  
Plant Density ◽  
Fluorescent Protein ◽  
Root Density ◽  
Weed Species ◽  
Belowground Competition ◽  
Higher Plant ◽  
Common Lambsquarters ◽  
Redroot Pigweed

Competition between crops and weeds may be stronger at the root than at the shoot level, but belowground competition remains poorly understood, due to the lack of suitable methods for root discrimination. Using a transgenic maize line expressing green fluorescent protein (GFP), we nondestructively discriminated maize roots from weed roots. Interactions between GFP-expressing maize, common lambsquarters, and redroot pigweed were studied in two different experiments with plants arranged in rows at a higher plant density (using boxes with a surface area of 0.09 m2) and in single-plant arrangements (using boxes with a surface area of 0.48 m2). Root density was screened using minirhizotrons. Relative to maize that was grown alone, maize root density was reduced from 41 to 87% when it was grown with redroot pigweed and from 27 to 73% when it was grown with common lambsquarters compared to maize grown alone. The calculated root : shoot ratios as well as the results of shoot dry weight and root density showed that both weed species restricted root growth more than they restricted shoot growth of maize. The effect of maize on the root density of the weeds ranged from a reduction of 25% to an increase of 23% for common lambsquarters and a reduction of 42 to 6% for redroot pigweed. This study constitutes the first direct quantification of root growth and distribution of maize growing together with weeds. Here we demonstrate that the innovative use of transgenic GFP-expressing maize combined with the minirhizotron technique offers new insights on the nature of the response of major crops to belowground competition with weeds.

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