scholarly journals Chitosan biostimulant controls infection of cucumber by Phytophthora capsici through suppression of asexual reproduction of the pathogen

2019 ◽  
Vol 72 (1) ◽  
Author(s):  
Fatematuz Zohara ◽  
Musrat Zahan Surovy ◽  
Amena Khatun ◽  
Md. F. R. K. Prince ◽  
Md. Abdul Mannan Akanda ◽  
...  
Keyword(s):  
Seed Germination ◽  
Phytophthora Capsici ◽  
Growth Promoter ◽  
Dependent Manner ◽  
Damping Off ◽  
Safe Alternative ◽  
Cucumber Seedlings ◽  
Mycelial Plug ◽  
Environmentally Safe

The biopolymer chitosan is a derivative of chitin, which can promote plant growth and protect plants from phytopathogens. This study aimed to evaluate the efficacy of chitosan as a biostimulant and a biorational agent to protect cucumber plants from damping-off disease caused by <em>Phytophthora capsici</em>. Cucumber seeds were treated with a range of chitosan concentrations, viz. 0, 125, 250, and 500 ppm, to evaluate effect on seed germination and fresh root and shoot weight of the seedlings. Chitosan significantly (<em>p</em> ≤ 0.05) enhanced seed germination and root and shoot growth of cucumber in a dose-dependent manner up to 500 ppm. Application of in vitro chitosan suspension onto <em>P. capsici</em> mycelial plug suppressed growth of mycelia, formation of sporangia, and release of <em>P. capsici</em> zoospores at 125–500 ppm concentrations. Cucumber seedlings from chitosan-treated seeds showed enhanced resistance to damping-off disease caused by <em>P. capsici</em> compared to untreated control. Cucumber seedlings from 500 ppm chitosan seed treatment showed 100% disease resistance against damping off caused by <em>P. capsici</em>. These results suggest that chitosan could be used as a natural and environmentally safe alternative to a synthetic growth promoter and pesticide for sustainable production of cucumber.

scholarly journals Fungicide Seed Treatment Effects on Seedling Damping-off of Pumpkin Caused by Phytophthora capsici

Plant Disease ◽  
2003 ◽  
Vol 87 (1) ◽  
pp. 63-68 ◽  
Author(s):  
M. Babadoost ◽  
S. Z. Islam
Keyword(s):  
Seed Germination ◽  
Untreated Control ◽  
Mycelial Growth ◽  
Seed Treatment ◽  
Culture Medium ◽  
Phytophthora Capsici ◽  
Field Trials ◽  
Seedling Vigor ◽  
Damping Off

Apron XL LS (mefenoxam) and Allegiance FL (metalaxyl) were highly inhibitory to growth of mycelium of Phytophthora capsici in vitro. Effective dose (ED50) of mefenoxam and metalaxyl for 50% inhibition of mycelial growth, for all five isolates of P. capsici tested, was 0.98 and 0.99 μg a.i./ml of culture medium, respectively. For mefenoxam at 200 μg a.i./ml, sporangium and zoospore germination were reduced by 92 and 96%, respectively, and 21 and 24%, respectively, for metalaxyl. In greenhouse studies, seed treatment with mefenoxam (0.42 ml of Apron XL LS/kg of seed) and metalaxyl (0.98 ml of Allegiance FL/kg of seed) significantly reduced pre- and post-emergence damping-off of seedlings caused by P. capsici in three pumpkin cultivars (Dickinson, Hybrid-401, and Hybrid-698) tested. Thirty-one days after seeding, at inoculum levels of 0, 90, 600, 1,400, and 4,000 CFU/g of soil, the average seedling stands for mefenoxam treatment were 98.4, 93.8, 88.3, 77.8, and 64.8%; for metalaxyl, 99.1, 85.3, 85.8, 73.5, and 59.3; and for the untreated control, 97.5, 55.2, 45.7, 37.0, and 22.9%, respectively. In field trials, the average seedling stands 35 days after seeding were 76.7, 74.7, and 44.9% for mefenoxam, metalaxyl, and untreated control, respectively. Seed treatment with mefenoxam or metalaxyl did not have any significant effect on either seed germination or seedling vigor.

Variations in Pathogenicity of Three Different Forms of Rhizoctonia Inoculum and Assessment of Cultivar Resistance of Sugar Beet

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Haque ME ◽  
◽  
Parvin MS ◽  
Keyword(s):  
Seed Germination ◽  
Sugar Beet ◽  
Root Rot ◽  
Large Scale ◽  
Culture Media ◽  
Damping Off ◽  
Require Time ◽  
Time Space ◽  
The Usa

Rhizoctonia solani causes pre-emergence and post-emergence damping-off, as well as crown and root rot of sugar beet (Beta vulgaris L.), which significantly affects the yield returns in the USA and Europe. The pathogen overwinters as sclerotia or melanized mycelium. Traditionally, the resistance of cultivars to R. solani is evaluated by scoring disease reactions at the crowns and roots of older seedlings, thus resistance is not evaluated during seed germination. Moreover, earlier studies evaluated cultivars resistance to R. solani using colonized whole barley or wheat grains which, unlike sclerotia, are artificial inocula of the pathogen that require time, space and technical know-how to produce. Moreover, colonized grains are prone to contamination with other pathogens, consumed by rodents/birds while applied in the field, and are often uneconomic. Considering those limitations, a study was undertaken (1) to develop in vitro methods to generate large-scale sclerotia, (2) to compare pathogenic potentials of sclerotia, mycelia, and colonized barley grains for optimization of dampingoff assays, and (3) to evaluate Rhizoctonia resistance of selected commercial cultivars during the seed germination phase. Comparing six different culture media, we found that R. solani had the highest radial growth (8.9 ± 0.04, cm³) at 8-days and the maximum number of sclerotia produced (203 ± 4.6) at 28-days in CV8 medium. We demonstrated significant differences in pathogenicity of the three different forms of R. solani inocula and susceptibility of cultivars to preand post-emergence damping-off. The highest pre-emergence damping-off and root rot were observed with sclerotia, and the highest post-emergence dampingoff was recorded with both sclerotial and colonized barley inocula. In addition, varietal differences in susceptibility to pre- and post-emergence damping-off were noted. The highest pre-emergence damping-off was recorded on cv Crystal 101RR and lowest in Maribo MA 504. The highest post-emergence damping-off was recorded on BTS 8500 and the lowest in Crystal 467. The maximum mean root rot was observed in BTS 8500, BTS 8606, and Crystal 101R. Our studies demonstrated that sclerotia serve as efficient natural inocula, reemphasized that host-pathogen interactions differ at the early vs. late stages of sugar beet growth, and highlighted the need to reevaluate commercial sugar beet cultivars for resistance at the seed germination stage.

scholarly journals Platelet-Rich Plasma Improves the Wound Healing Potential of Mesenchymal Stem Cells through Paracrine and Metabolism Alterations

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Barbara Hersant ◽  
Mounia Sid-Ahmed ◽  
Laura Braud ◽  
Maud Jourdan ◽  
Yasmine Baba-Amer ◽  
...  
Keyword(s):  
Stem Cells ◽  
Wound Healing ◽  
Mesenchymal Stem Cells ◽  
Platelet Rich Plasma ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Dependent Manner ◽  
Safe Alternative

Chronic and acute nonhealing wounds represent a major public health problem, and replacement of cutaneous lesions by the newly regenerated skin is challenging. Mesenchymal stem cells (MSC) and platelet-rich plasma (PRP) were separately tested in the attempt to regenerate the lost skin. However, these treatments often remained inefficient to achieve complete wound healing. Additional studies suggested that PRP could be used in combination with MSC to improve the cell therapy efficacy for tissue repair. However, systematic studies related to the effects of PRP on MSC properties and their ability to rebuild skin barrier are lacking. We evaluated in a mouse exhibiting 4 full-thickness wounds, the skin repair ability of a treatment combining human adipose-derived MSC and human PRP by comparison to treatment with saline solution, PRP alone, or MSC alone. Wound healing in these animals was measured at day 3, day 7, and day 10. In addition, we examined in vitro and in vivo whether PRP alters in MSC their proangiogenic properties, their survival, and their proliferation. We showed that PRP improved the efficacy of engrafted MSC to replace lost skin in mice by accelerating the wound healing processes and ameliorating the elasticity of the newly regenerated skin. In addition, we found that PRP treatment stimulated in vitro, in a dose-dependent manner, the proangiogenic potential of MSC through enhanced secretion of soluble factors like VEGF and SDF-1. Moreover, PRP treatment ameliorated the survival and activated the proliferation of in vitro cultured MSC and that these effects were accompanied by an alteration of the MSC energetic metabolism including oxygen consumption rate and mitochondrial ATP production. Similar observations were found in vivo following combined administration of PRP and MSC into mouse wounds. In conclusion, our study strengthens that the use of PRP in combination with MSC might be a safe alternative to aid wound healing.

scholarly journals Role of Trichoderma aggressivum f. europaeum as Plant-Growth Promoter in Horticulture

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1004 ◽  
Author(s):  
Brenda Sánchez-Montesinos ◽  
Fernando Diánez ◽  
Alejandro Moreno-Gavíra ◽  
Francisco J. Gea ◽  
Mila Santos
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Added Value ◽  
Growth Promoter ◽  
Tomato Seed ◽  
Promoting Effect ◽  
Commercial Plant ◽  
Plant Nursery ◽  
Different Doses

The main objective of this study was to determine the capacity of Trichoderma aggressivum f. europaeum to promote pepper and tomato seedling growth compared to that of T. saturnisporum, a species recently characterised as a biostimulant. Consequently, in vitro seed germination and seedling growth tests were performed under commercial plant nursery conditions. Additionally, the effects of different doses and a mixture of both species on seedling growth under plant nursery and subsequently under greenhouse conditions were determined. Furthermore, mass production of spores was determined in different substrates, and their siderophore and indole acetic acid production and phosphate (P) solubilisation capacity were also determined. Direct application of Trichoderma aggressivum f. europaeum to seeds in vitro neither increases the percentage of pepper and tomato seed germination nor improves their vigour index. However, substrate irrigation using different doses under commercial plant nursery conditions increases the quality of tomato and pepper seedlings. Tomato roots increased by 66.66% at doses of 106 spores per plant. Applying T. aggressivum f. europaeum or T. saturnisporum under plant nursery conditions added value to seedlings because their growth-promoting effect is maintained under greenhouse conditions up to three months after transplantation. The combined application of the two species had no beneficial effect in relation to that of the control. The present study demonstrates the biostimulant capacity of T. aggressivum f. europaeum in pepper and tomato plants under commercial plant nursery and greenhouse conditions.

scholarly journals The Effect of Various pH Medium on the Secondary Metabollites Production from Trichoderma harzianum T10 to Control Damping Off on Cucumber Seedlings

2020 ◽  
Vol 3 (2) ◽  
pp. 65
Author(s):  
Nur Chalimah ◽  
Loekas Soesanto ◽  
Woro Sri Suharti
Keyword(s):  
Secondary Metabolites ◽  
Trichoderma Harzianum ◽  
Disease Incidence ◽  
In Vitro Assay ◽  
Cucumber Seedling ◽  
Damping Off ◽  
In Planta ◽  
Vitro Assay ◽  
Cucumber Seedlings

Damping-off is one of the main diseases in cucumber seedlings caused by Pythium sp. Secondary metabolites of Trichoderma harzianum T10 can conduct the control of the disease. The pH of the medium influences the production of secondary metabolites. The research aimed to determine the effective pH medium on production of T. harzianum T10 secondary metabolites, and the effect of the T. harzianum T10 secondary metabolites application in damping-off disease control also to the growth of cucumber seedling. The research was consist of two steps; 1) in vitro assay with various pH levels 5; 3; 3.5; 4; 4.5; 5.5; 6; 6.5; and 7, 2) In planta treatments consisted of control, fungicide (Mancozeb), secondary metabolites in pH 5 and 5.5 with the concentration of 5, 10 and 15% each. The research showed that: 1) the effective pH medium for the production of T. harzianum T10 secondary metabolites was 5 and 5.5. 2) application of the T. harzianum T10 secondary metabolites on pH 5 and 5.5 with a concentration of 5, 10, and 15% could decrease the disease incidence and support cucumber seedling growth.

scholarly journals Cytokinin-like effects of chitosan on in vitro culture of Origanum vulgare L.

Italus Hortus ◽  
2021 ◽  
Vol 28 (1) ◽  
pp. 100
Author(s):  
Noor Premi ◽  
Arda Acemi ◽  
Fazil Ozen
Keyword(s):  
Seed Germination ◽  
Shoot Elongation ◽  
Adventitious Rooting ◽  
Dependent Manner ◽  
Origanum Vulgare ◽  
Concentration Dependent Manner ◽  
Leaf Production ◽  
Shoot Production ◽  
Better Than

Oregano (Origanum vulgare L.) is a multi-purpose plant species with medicinal, culinary, and ornamental merit, which needs to be produced at an industrial scale. In the present research, effects of N-acetylated (10%) chitosan (CHT), 6-benzylaminopurine (BAP), and kinetin (KIN) on in vitro seed germination and shoot development in O. vulgare were studied in a concentration-dependent manner. The seed germination and shoot induction rates were mostly enhanced after CHT and KIN treatments, while BAP treatments reduced the rates. The chitosan treatment significantly triggered leaf production and shoot elongation better than the cytokinin treatments. The maximum shoot length (4.38±0.17 cm) and leaf number (17.71±0.69 leaves per shoot) were reached after chitosan treatment at 0.75 mg L-1, while shoot numbers were reduced after all chitosan and cytokinin treatments at low levels. However, shoot production was significantly enhanced in the presence of 2.0 and 4.0 mg L-1 KIN in the medium. Adventitious rooting without using auxins also occurred during the incubation period. The cluster analysis showed that the effects of 0.50 and 0.75 mg L-1 CHT treatments were better than BAP and KIN in stimulating shoot growth and leaf development in oregano. This study suggested that CHT might be used as a substitute for synthetic cytokinins to produce longer shoots and a high number of leaves in oregano propagation. Therefore, CHT might play a cytokinin-like role in plant tissue cultures. However, the effects of chitosan treatment might differ among species and according to its chemical structure

scholarly journals Transforming growth factor-beta 1 bifunctionally regulates murine macrophage proliferation

Blood ◽  
1992 ◽  
Vol 79 (7) ◽  
pp. 1679-1685 ◽  
Author(s):  
K Fan ◽  
Q Ruan ◽  
L Sensenbrenner ◽  
B Chen
Keyword(s):  
Growth Factor ◽  
Synergistic Effect ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Growth Promoter ◽  
Dependent Manner ◽  
Tgf Beta ◽  
Gm Csf ◽  
Growth Factor Beta

Abstract Transforming growth factor-beta (TGF-beta) is a family of polypeptide growth factors with multiple functional activities. Recent studies suggest that TGF-beta is a selective inhibitor of hematopoietic cells. In this report, we study the effect of TGF-beta 1 on the proliferation of murine peritoneal exudate macrophages (PEM) in response to purified murine recombinant granulocyte-macrophage colony-stimulating factor (rMuGM-CSF) and human recombinant M-CSF (rHuM-CSF). In mice, PEM and other types of tissue macrophages display multiple types of receptors for CSFs and respond to them, either alone or in combination, to undergo extensive proliferation in vitro. Recombinant human TGF-beta 1 (rHuTGF-beta 1) (0.1 to 1.0 ng/mL) markedly enhanced the growth of PEM in response to rMuGM-CSF but inhibited their responsiveness to rHuM- CSF. Similar effects of rHuTGF-beta 1 were also detected using murine pulmonary alveolar macrophages (PAM) and bone marrow-derived macrophages (BMDM). Receptor binding assays using iodinated rMuGM-CSF and rHuM-CSF showed that rHuTGF-beta 1 treatment greatly enhanced the expression of GM-CSF receptors in PEM, in a time- and dose-dependent manner, suggesting a possible mechanism for the synergistic effect of TGF-beta 1. On the other hand, the expression of M-CSF receptors was not affected by TGF-beta 1 treatment. Analysis by mRNA PCR showed that the synergistic effect of TGF-beta 1 is not due to autocrine CSFs produced by treated cells. Our results suggest that TGF-beta 1 is an important regulator of macrophage proliferation. Depending on the types of CSFs present, TGF-beta 1 may act either as a growth promoter or inhibitor.

Isolation, characterization, and formulation of antagonistic bacteria for the management of seedlings damping-off and root rot disease of cucumber

2014 ◽  
Vol 60 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Salah Eddin Khabbaz ◽  
Pervaiz A. Abbasi
Keyword(s):  
Plant Growth ◽  
Root Rot ◽  
Storage Period ◽  
Pythium Ultimum ◽  
In Vitro Tests ◽  
Antagonistic Bacteria ◽  
Damping Off ◽  
Biochemical Tests ◽  
Cucumber Seedlings

Antagonistic bacteria are common soil inhabitants with potential to be developed into biofungicides for the management of seedling damping-off, root rot, and other soil-borne diseases of various crops. In this study, antagonistic bacteria were isolated from a commercial potato field and screened for their growth inhibition of fungal and oomycete pathogens in laboratory tests. The biocontrol potential of the 3 most effective antagonistic bacteria from the in vitro tests was evaluated against seedling damping-off and root rot of cucumber caused by Pythium ultimum. Based on phenotypic characteristics, biochemical tests, and sequence analysis of 16S–23S rDNA gene, the 3 antagonistic bacteria were identified as Pseudomonas fluorescens (isolate 9A-14), Pseudomonas sp. (isolate 8D-45), and Bacillus subtilis (isolate 8B-1). All 3 bacteria promoted plant growth and suppressed Pythium damping-off and root rot of cucumber seedlings in growth-room assays. Both pre- and post-planting application of these bacteria to an infested peat mix significantly increased plant fresh masses by 113%–184% and percentage of healthy seedlings by 100%–290%, and decreased damping-off and root rot severity by 27%–50%. The peat and talc formulations of these antagonistic bacteria applied as seed or amendment treatments to the infested peat mix effectively controlled Pythium damping-off and root rot of cucumber seedlings and enhanced plant growth. The survival of all 3 antagonistic bacteria in peat and talc formulations decreased over time at room temperature, but the populations remained above 108CFU/g during the 180-day storage period. The peat formulation of a mixture of 3 bacteria was the best seed treatment, significantly increasing the plant fresh masses by 245% as compared with the Pythium control, and by 61.4% as compared with the noninfested control. This study suggests that the indigenous bacteria from agricultural soils can be developed and formulated as biofungicides for minimizing the early crop losses caused by seedling damping-off and root rot diseases.

scholarly journals Transforming growth factor-beta 1 bifunctionally regulates murine macrophage proliferation

Blood ◽  
1992 ◽  
Vol 79 (7) ◽  
pp. 1679-1685 ◽  
Author(s):  
K Fan ◽  
Q Ruan ◽  
L Sensenbrenner ◽  
B Chen
Keyword(s):  
Growth Factor ◽  
Synergistic Effect ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Growth Promoter ◽  
Dependent Manner ◽  
Tgf Beta ◽  
Gm Csf ◽  
Growth Factor Beta

Transforming growth factor-beta (TGF-beta) is a family of polypeptide growth factors with multiple functional activities. Recent studies suggest that TGF-beta is a selective inhibitor of hematopoietic cells. In this report, we study the effect of TGF-beta 1 on the proliferation of murine peritoneal exudate macrophages (PEM) in response to purified murine recombinant granulocyte-macrophage colony-stimulating factor (rMuGM-CSF) and human recombinant M-CSF (rHuM-CSF). In mice, PEM and other types of tissue macrophages display multiple types of receptors for CSFs and respond to them, either alone or in combination, to undergo extensive proliferation in vitro. Recombinant human TGF-beta 1 (rHuTGF-beta 1) (0.1 to 1.0 ng/mL) markedly enhanced the growth of PEM in response to rMuGM-CSF but inhibited their responsiveness to rHuM- CSF. Similar effects of rHuTGF-beta 1 were also detected using murine pulmonary alveolar macrophages (PAM) and bone marrow-derived macrophages (BMDM). Receptor binding assays using iodinated rMuGM-CSF and rHuM-CSF showed that rHuTGF-beta 1 treatment greatly enhanced the expression of GM-CSF receptors in PEM, in a time- and dose-dependent manner, suggesting a possible mechanism for the synergistic effect of TGF-beta 1. On the other hand, the expression of M-CSF receptors was not affected by TGF-beta 1 treatment. Analysis by mRNA PCR showed that the synergistic effect of TGF-beta 1 is not due to autocrine CSFs produced by treated cells. Our results suggest that TGF-beta 1 is an important regulator of macrophage proliferation. Depending on the types of CSFs present, TGF-beta 1 may act either as a growth promoter or inhibitor.

scholarly journals Aspergillus terreus obtained from mangrove exhibits antagonistic activities against Pythium aphanidermatum-induced damping-off of cucumber

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7884 ◽  
Author(s):  
Hanaa Al-Shibli ◽  
Sergey Dobretsov ◽  
Abdulrahman Al-Nabhani ◽  
Sajeewa S.N. Maharachchikumbura ◽  
Velazhahan Rethinasamy ◽  
...  
Keyword(s):  
Aspergillus Terreus ◽  
Plant Pathogens ◽  
Dry Weight ◽  
Avicennia Marina ◽  
Pythium Aphanidermatum ◽  
Antagonistic Activity ◽  
Damping Off ◽  
Cucumber Seedlings ◽  
Percent Mortality

A study was conducted to investigate the potential of Aspergillus terreus obtained from Avicennia marina mangrove roots in inhibiting Pythium aphanidermatum and damping-off disease of cucumber. Aspergillus terreus exhibited in vitro inhibition of Pythium aphanidermatum growth. Electron microscope examination revealed that the antagonistic fungal isolate resulted in shrinking and groves in Pythium hypha. When Aspergillus terreus culture filtrate was added to Pythium aphanidermatum, it resulted in a significant increase (by 73%) in electrolyte leakage from Pythium hypha compared to the control, as well as significant reduction (by 71%) in oospore production. The Aspergillus terreus culture was also found to produce a cellulase enzyme, which is suggested to be involved in the antagonism against Pythium aphanidermatum. Adding Aspergillus terreus to soil infested with Pythium aphanidermatum significantly reduced percent mortality in cucumber seedlings by 70%. Aspergillus terreus, when applied alone on cucumber seedlings, did not show any suppressive effects on cucumber growth (length and fresh and dry weight). This appears to be the first report of isolation from mangrove of Aspergillus terreus with antagonistic activity against Pythium aphanidermatum-induced damping-off of cucumber. The study indicates that fungal isolates obtained from marine environments may serve as potential biocontrol agents against some plant pathogens.

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