Influence of nitrogen fertilizers on yield and antifungal bioactivity of Tulbaghia violacea L.

Tulbaghia is known to have antifungal properties that can be used in the treatment of both human and plant pathogens and is used in traditional medicine in South Africa. Increasing demands for plant material makes it necessary to cultivate this species on a large scale. Unfortunately, cultivation can lead to a reduction in the biological activity of plants making them unsuitable for use. In light of the lack of knowledge regarding the agronomic requirements of this plant, the aim of this study was to determine the effect of several rates and two forms of nitrogenous fertilizer on the yield and biological activity of Tulbaghia violacea. Plants were cultivated in sand while the basic fertilization used was the same as that of garlic (20 kg P ha−1, 75 kg K ha−1), a plant from the same family, containing similar active ingredients. Nitrogen was applied once at the beginning of the trial at rates of 30, 60, 120, and 180 kg ha−1 in the form of either nitrate or ammonium. Vegetative growth was quantified in terms of number of leaves and leaf area as well as root and leaf dry mass, while harvested material was tested for antifungal activity. The results indicated that compared with the untreated control, increasing N-rates in both the nitrate and ammonium forms increased leaf number and leaf area as well as both root and leaf dry mass. However, at a rate above 60 kg ha−1, and especially at 180 kg ha−1, the nitrate form stimulated growth more markedly than the ammonium form, whereas antifungal activity decreased sharply and almost linearly as the application rate was increased. Although growth was not stimulated to the same extent by the ammonium form, it increased the in-vitro antifungal activity at different levels during different times of the growing season. From an ornamental perspective, nitrate is the preferred nitrogenous form but, from a bioactivity perspective, ammonium is recommended.

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Effect of C6-Volatiles on Bioluminescent Plant Pathogens

HortScience ◽

10.21273/hortsci.33.3.557d ◽

1998 ◽

Vol 33 (3) ◽

pp. 557d-557

Author(s):

Jennifer Warr ◽

Fenny Dane ◽

Bob Ebel

Keyword(s):

Biological Activity ◽

Bacterial Growth ◽

Xanthomonas Campestris ◽

Plant Pathogens ◽

Genetically Engineered ◽

The Other ◽

Computer Assisted ◽

Signal Molecules ◽

Low Concentrations

C6 volatile compounds are known to be produced by the plant upon pathogen attack or other stress-related events. The biological activity of many of these substances is poorly understood, but some might produce signal molecules important in host–pathogen interactions. In this research we explored the possibility that lipid-derived C6 volatiles have a direct effect on bacterial plant pathogens. To this purpose we used a unique tool, a bacterium genetically engineered to bioluminesce. Light-producing genes from a fish-associated bacterium were introduced into Xanthomonas campestris pv. campestris, enabling nondestructive detection of bacteria in vitro and in the plant with special computer-assisted camera equipment. The effects of different C6 volatiles (trans-2 hexanal, trans-2 hexen-1-ol and cis-3 hexenol) on growth of bioluminescent Xanthomonas campestris were investigated. Different volatile concentrations were used. Treatment with trans-2 hexanal appeared bactericidal at low concentrations (1% and 10%), while treatments with the other volatiles were not inhibitive to bacterial growth. The implications of these results with respect to practical use of trans-2 hexanal in pathogen susceptible and resistant plants will be discussed.

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Physiological responses of two tropical weeds to shade: I. Growth and biomass allocation

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x1999000600004 ◽

1999 ◽

Vol 34 (6) ◽

pp. 944-952 ◽

Cited By ~ 1

Author(s):

Moacyr Bernardino Dias-Filho

Keyword(s):

Leaf Area ◽

Weed Management ◽

Dry Mass ◽

High Light ◽

Low Light ◽

Light Regimes ◽

Leaf Dry Mass ◽

Lower Ability ◽

Total Plant ◽

Plant Dry Mass

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in Brazilian Amazonia, were grown in controlled environment cabinets under high (800-1000 µmol m-² s-¹) and low (200-350 µmol m-² s-¹) light regimes during a 40-day period. For both species leaf dry mass and leaf area per total plant dry mass, and leaf area per leaf dry mass were higher for low-light plants, whereas root mass per total plant dry mass was higher for high-light plants. High-light S. cayennensis allocated significantly more biomass to reproductive tissue than low-light plants, suggesting a probably lower ability of this species to maintain itself under shaded conditions. Relative growth rate (RGR) in I. asarifolia was initially higher for high-light grown plants and after 20 days started decreasing, becoming similar to low-light plants at the last two harvests (at 30 and 40 days). In S. cayennensis, RGR was also higher for high-light plants; however, this trend was not significant at the first and last harvest dates (10 and 40 days). These results are discussed in relation to their ecological and weed management implications.

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FLAME RETARDANTS EFFECTS ON THE INITIAL GROWTH OF Schizolobium amazonicum HUBER EX DUCKE

Revista Árvore ◽

10.1590/1806-908820210000014 ◽

2021 ◽

Vol 45 ◽

Author(s):

Elen Silma Oliveira Cruz Ximenes ◽

Andréa Carvalho da Silva ◽

Adilson Pacheco de Souza ◽

Josiane Fernandes Keffer ◽

Alison Martins dos Anjos ◽

...

Keyword(s):

Flame Retardant ◽

Leaf Area ◽

Flame Retardants ◽

Biomass Accumulation ◽

Dry Mass ◽

Initial Growth ◽

Environmental Implications ◽

Leaf Dry Mass ◽

Height Increase ◽

Positive Effect

ABSTRACT Flame retardants are efficient in fighting wildfire; however, their environmental implications, especially regarding the vegetation, need to be clarified. This work aimed at assessing the effects of flame retardant on the initial growth of Schizolobium amazonicum. Treatments consisted in applying different flame retardant concentrations via substrate and leaf: Phos-Chek WD-881® (0, 3.00, 6.00, 8.00 and 10.00 mL L-1), Hold Fire® (0, 7.00, 9.00, 12.00 and 15.00 mL L-1) and water-retaining polymer Nutrigel® used as alternative retardant (0, 0.25, 0.50, 0.75 and 1.00 g L-1). Growth analyses were carried out to assess the effects of these substances (10 repetitions per treatment). The aliquot of 10.00 mL L-1 of Phos-Chek WD881 applied on the leaves led to an increase of 70% in leaf area and 15% in seedling height. The same Phos-Chek concentration favored height increase (32%) and total dry mass accumulation (33%) throughout time. The concentration of 15 mL L-1 of Hold Fire® applied on leaves, compromised 45% the accumulation of dry biomass in the seedling. Initially, 1.00 g L-1 of Nutrigel® applied via substrate led to an increase of 70% in leaf area, 29% in plant height, and 89% in leaf dry mass. Therefore, Phos-Chek applied on leaves favored shoot growth in S. amazonicum. Hold Fire® applied on leaves impaired biomass accumulation in seedlings. Nutrigel® applied on substrate does not cause long-lasting damage to the initial growth of S. amazonicum. The aliquot of 0.50 g L-1 administered via polymer leave had positive effect on seedling shoot.

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EMISSÃO DE ÓXIDO NITROSO ASSOCIADO AO USO DE UREIA NO CULTIVO DE MELÃO AMARELO

Nativa ◽

10.31413/nativa.v6i6.5459 ◽

2018 ◽

Vol 6 (6) ◽

pp. 600

Author(s):

Vanessa Cláudia Vasconcelos Segundo ◽

Renato Innecco ◽

Ebenézer De Oliveira Silva

Keyword(s):

Leaf Area ◽

Aerial Part ◽

Dry Mass ◽

Nitrogen Fertilizers ◽

Root Part ◽

Randomized Design ◽

Number Of Leaves ◽

Completely Randomized Design ◽

Brazilian Northeast ◽

Total Soil Nitrogen

O meloeiro tem grande importância econômica para o Nordeste brasileiro. Entretanto, em seu cultivo utiliza-se insumos que podem prejudicar o ambiente; como, os fertilizantes nitrogenados. Objetivou-se avaliar a emissão de N2O em cultivo de meloeiro amarelo ‘Goldex’. O experimento foi instalado em delineamento inteiramente casualizado, com cinco repetições. Os tratamentos foram: 0 (controle), 1,0; 1,5 e 2 vezes a quantidade de nitrogênio recomendada para cada estádio. Foi analisado o fluxo de N2O, área foliar, número de folhas, massa seca da parte aérea, massa seca dos frutos, massa seca da parte radicular, nitrogênio total do solo, das plantas e N (NH4+ e NO3-) do solo. O fluxo de N2O teve comportamento temporal irregular durante a fase de plântulas e crescente na floração. Os tratamentos afetaram significativamente a área foliar, número de folhas, massa seca da parte aérea, massa seca da parte radicular, nitrogênio da parte aérea e parte radicular das plantas e do solo. A aplicação de nitrogênio, em dosagens superiores à recomendada, não aumentou a produção do meloeiro. E o cálculo do fator de emissão mostrou que a emissão do N2O não atingiu valores prejudiciais ao ambiente.Palavras-chave: fator de emissão, efeito estufa e nitrogênio. NITROUS OXIDE EMISSION ASSOCIATED WITH UREA USE THE YELLOW MELON CROP ABSTRACT: The melon has great economic importance for the Brazilian Northeast. However, in its cultivation uses inputs that can harm the environment; Such as nitrogen fertilizers. The objective of this study was to evaluate the emission of N2O in yellow 'Goldex' cultivar. The experiment was installed in a completely randomized design with five replications. The treatments were: 0 (control), 1.0; 1.5 and 2 times the amount of nitrogen recommended for each stage. N2O flux, leaf area, leaf number, shoot dry mass, fruit dry mass, dry mass of the root portion, total soil nitrogen, of the plants and N (NH4 + and NO3 -) of the soil were analyzed. The flow of N2O had irregular temporal behavior during the seedling phase and increased in flowering. The treatments affected significantly the leaf area, number of leaves, dry mass of the aerial part, dry mass of the root part, nitrogen of the aerial part and root part of the plants and the soil. The application of nitrogen, in dosages higher than the recommended one, did not increase the production of the melon. And the calculation of the emission factor showed that the emission of N2O did not reach values harmful to the environment.Keywords: emission fator, greenhouse and nitrogen.

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Staphylococcus saprophyticus L-38 produces volatile 3,3-dimethyl-1,2-epoxybutane with strong inhibitory activity against Aspergillus flavus germination and aflatoxin production

World Mycotoxin Journal ◽

10.3920/wmj2019.2495 ◽

2020 ◽

Vol 13 (2) ◽

pp. 247-258 ◽

Cited By ~ 1

Author(s):

A.D. Gong ◽

G.J. Sun ◽

Z.Y. Zhao ◽

Y.C. Liao ◽

J.B. Zhang

Keyword(s):

Food Safety ◽

Antifungal Activity ◽

Aspergillus Flavus ◽

Plant Pathogens ◽

Aflatoxin Production ◽

Gas Chromatography Mass Spectrometry ◽

Total Peak Area ◽

Staphylococcus Saprophyticus

Controlling proliferation and aflatoxin production by Aspergillus flavus is a pressing challenge for global food safety and security. Marine bacterium Staphylococcus saprophyticus strain L-38 showed excellent antifungal activity toward A. flavus in vitro and in vivo. In sealed, non-contact confrontation assays, L-38 completely inhibited conidial germination and mycelial growth of A. flavus through the production of volatile organic compounds (VOCs). Gas chromatography-mass spectrometry identified 3,3-dimethyl-1,2-epoxybutane (3-DE) as the most abundant VOC (32.61% of total peak area, 78% matching). Exposure of A. flavus cultures to synthetic 3-DE similarly demonstrated strong inhibition of growth. Moreover, culture of L-38 in a sealed chamber with maize or peanuts artificially inoculated with A. flavus, at high water activity, resulted in significant inhibition of A. flavus germination and aflatoxin biosynthesis. Scanning electron microscopy of these samples revealed severe damage to conidial cells and hyphae compared to samples not exposed to L-38. L-38 also showed broad and effective antifungal activity toward eight other phytopathogenic fungi including Aspergillus niger, Fusarium verticillioides, Fusarium graminearum, Sclerotinia sclerotiorum, Rhizoctonia solani, Alternaria alternata, Monilinia fructicola, and Botrytis cinerea. This work introduces S. saprophyticus L-38 as a potential biocontrol agent and demonstrates the efficacy of the volatile 3-DE in the control of A. flavus and other destructive plant pathogens for post-harvest food safety.

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Antifungal activity of extracts from endophytic fungi associated with Smallanthus maintained in vitro as autotrophic cultures and as pot plants in the greenhouse

Canadian Journal of Microbiology ◽

10.1139/w2012-088 ◽

2012 ◽

Vol 58 (10) ◽

pp. 1202-1211 ◽

Cited By ~ 14

Author(s):

Luiz H. Rosa ◽

Nurhayat Tabanca ◽

Natascha Techen ◽

Zhiqiang Pan ◽

David E. Wedge ◽

...

Keyword(s):

Antifungal Activity ◽

Endophytic Fungi ◽

Plant Pathogens ◽

Cultivation Conditions ◽

Smallanthus Sonchifolius ◽

Fungal Plant Pathogens ◽

In The Wild ◽

Fungal Assemblages ◽

Pot Plants

The endophytic fungal assemblages associated with Smallanthus sonchifolius (Poepp.) H. Rob. and Smallanthus uvedalius (L.) Mack. ex Small growing in vitro autotrophic cultures and in the greenhouse were identified and evaluated for their ability to produce bioactive compounds. A total of 25 isolates were recovered that were genetically closely related to species of the genera Bionectria , Cladosporium , Colletotrichum , Fusarium , Gibberella , Hypocrea , Lecythophora , Nigrospora , Plectosphaerella , and Trichoderma . The endophytic assemblages of S. sonchifolius presented a greater diversity than the group isolated from S. uvedalius and demonstrated the presence of dominant generalist fungi. Extracts of all fungi were screened against the fungal plant pathogens. Ten extracts (41.6%) displayed antifungal activities; some of them had a broad antifungal activity. The phylotypes Lecythophora sp. 1, Lecythophora sp. 2, and Fusarium oxysporum were isolated from in vitro autotrophic cultures and displayed antifungal activity. The presence of bioactive endophytic fungi within S. sonchifolius and S. uvedalius suggests an ecological advantage against pathogenic attacks. This study revealed reduced numbers of endophytes in association with both Smallanthus species in controlled cultivation conditions compared with the endophytic communities of hosts collected in the wild environments. Even as reduced endophytic communities, these fungi continue to provide chemical protection for the host.

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Antifungal activity in vitro of Sapranthus microcarpus (Annonaceae) against phytopathogens

Acta Botanica Mexicana ◽

10.21829/abm126.2019.1420 ◽

2018 ◽

Author(s):

Iván De-la-Cruz-Chacón ◽

Nora Yazmin López-Fernández ◽

Christian Anabí Riley-Saldaña ◽

Marisol Castro Moreno ◽

Alma Rosa González-Esquinca

Keyword(s):

Antifungal Activity ◽

Fungal Pathogens ◽

Plant Pathogens ◽

Stem Bark ◽

Antimicrobial Activities ◽

Curvularia Lunata ◽

Root Bark ◽

Inhibitory Activities ◽

Alkaloid Extracts

Background and Aims: The phytochemistry study of Annonaceae has intensified in the last decades due to the discovery of secondary metabolites with antimicrobial activities. The inhibitory activities of extracts and compounds from these species for phytopathogens are less known. The antifungal activity of Sapranthus microcarpus was determined in vitro against six fungal pathogens of important crops.Methods: Hexane, methanol, and alkaloid extracts of the leaves and root and stem bark of S. microcarpus were evaluated to determine whether they could inhibit the mycelial growth of the phytopathogens. The combined activity of the most active extracts for each phytopathogen was also determined. The alkaloid liriodenine was isolated and identified as an antifungal principle.Key results: All extracts inhibited the growth of the six phytopathogens to some extent. The root bark alkaloid extract showed the highest activity. Fusarium oxysporum f. sp. lycopersici and Curvularia lunata were the most sensitive phytopathogens. Liriodenine was active against all the plant pathogens (minimum inhibitory concentrations of 125-500 nmol ml-1).Conclusions: Sapranthus microcarpus is a native natural resource with great phytochemical potential.

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Plant Growth Regulators in the in Vitro Cultivation of Acmella oleracea (L.)

Journal of Agricultural Studies ◽

10.5296/jas.v8i2.16863 ◽

2020 ◽

Vol 8 (2) ◽

pp. 774

Author(s):

Nastassja Kimberlly Lima ◽

Eloisa Schneider Da Silva ◽

Rayane Monique Sete Da Cruz ◽

Pedro Henrique Riboldi Monteiro ◽

Glacy Jaqueline Da Silva

Keyword(s):

Growth Regulators ◽

Root Length ◽

Aerial Part ◽

Large Scale ◽

Dry Mass ◽

Fresh Mass ◽

Limiting Factor ◽

Naphthalene Acetic Acid ◽

In Vitro Cultivation

Acmella oleracea is a tropical plant, typical of the northern region of Brazil. The species belongs to the Asteraceae family and has great therapeutic, pharmacological and industrial potential. A limiting factor for the production of this species on a large scale is the short life cycle. The tissue culture programs use synthetic hormones based on cytokinins, such as kinetin and benzylaminopurine (BAP) and auxins such as naphthalene acetic acid (ANA). The objective of this research was to evaluate the effect of growth regulators on the production of Acmella oleracea "in vitro". The experimental test was carried out with control (C), without the addition of growth regulators and five treatments, composed of: (T1) 0.1; (T2) 0.3; (T3) 0.5 mg L-1 kinetin; (T4) 0.1 mg L-1 of BAP and ANA; (T5) 0.5 mg L-1 of BAP and ANA. The experimental design was a completely randomized block in a factorial arrangement with six treatments, three blocks and twenty-five repetitions per block. The evaluated parameters were: germination, root formation, aerial part length, root length, aerial part fresh mass and root fresh mass, aerial part dry mass and root dry mass. The data obtained were subjected to analysis of variance (p <0.05) and compared using the Tukey test. The results showed that kinetin positively contributed to seed germination and aerial part dry mass development. Treatment 1 had the best results for the parameters root length, shoot length and root dry mass.

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Antifungal activity of saponins originated from Medicago hybrida against some ornamental plant pathogens

Acta Agrobotanica ◽

10.5586/aa.2006.061 ◽

2012 ◽

Vol 59 (2) ◽

pp. 51-58 ◽

Cited By ~ 9

Author(s):

Alicja Saniewska ◽

Anna Jarecka ◽

Zbigniew Biały ◽

Marian Jurzysta

Keyword(s):

Antifungal Activity ◽

Fusarium Oxysporum ◽

Botrytis Cinerea ◽

Plant Pathogens ◽

Pathogenic Fungi ◽

Ornamental Plant ◽

Mycelium Growth ◽

Medicagenic Acid ◽

Fungitoxic Effect

Antifungal activity of total saponins originated from roots of Medicago hybrida (Pourret) Trautv. were evaluated in vitro against six pathogenic fungi and eight individual major saponin glycosides were tested against one of the most susceptible fungi. The total saponins showed fungitoxic effect at all investigated concentrations (0.01%, 0.05% and 0.1%) but their potency was different for individual fungi. The highest saponin concentration (0.1%) was the most effective and the inhibition of Fusarium oxysporum f. sp. callistephi, Botrytis cinerea, Botrytis tulipae, Phoma narcissi, Fusarium oxysporum f. sp. narcissi was 84.4%, 69.9%, 68.6%, 57.2%, 55.0%, respectively. While Fusarium oxysporum Schlecht., a pathogen of Muscari armeniacum, was inhibited by 9.5% only. Eight major saponin glycosides isolated from the total saponins of M. hybrida roots were tested against the mycelium growth of Botrytis tulipae. The mycelium growth of the pathogen was greatly inhibited by hederagenin 3-O-β-D-glucopyranoside and medicagenic acid 3-O-β-D-glucopyranoside. Medicagenic acid 3-O-β-D-glucuronopyranosyl-28-O-β-D-glucopyranoside and oleanolic acid 3-O-[β-D-glucuronopyranosyl(1→2)-α-L-galactopyranosyl]-28-O-β-D-glucopyranoside showed low fungitoxic activity. Medicagenic acid 3-O-a-D-glucopyranosyl- 28-O-β-D-glucopyranoside, hederagenin 3-O-[α-L- hamnopyranosyl(1→2)-β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl]- 28-O-α-D-glucopyranoside and hederagenin 3-O-β-D-glucuronopyranosyl-28-O-β-D- lucopyranoside did not limit or only slightly inhibited growth of the tested pathogen. While 2β, 3β-dihydroxyolean-12 ene-23-al-28-oic acid 3-O-β-D-glucuronopyranosyl-28-O-β-D-glucopyranoside slightly stimulated mycelium growth of B. tulipae.

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Does the climate of the origin control anatomical characteristics of the vessel elements as well as different foliar traits in Fagus crenata?

Journal of Forest Science ◽

10.17221/93/2010-jfs ◽

2011 ◽

Vol 57 (No. 9) ◽

pp. 377-383 ◽

Cited By ~ 2

Author(s):

V. Bayramzadeh ◽

P. Attarod ◽

M.T. Ahmadi ◽

S. Rezaee Amruabadi ◽

T. Kubo

Keyword(s):

Leaf Area ◽

Dry Mass ◽

Fagus Crenata ◽

Anatomical Characteristics ◽

Vessel Area ◽

Unit Leaf ◽

Leaf Dry Mass ◽

Vessel Elements ◽

Foliar Traits ◽

Area Percentage

The relationships between climatic factors and anatomical characteristics of the vessel elements as well as different foliar traits were investigated in Fagus crenata seedlings originating from different provenances. Fagus crenata samples were prepared from Chichibu Research Forest of Tokyo University. In the present study, vessel number per mm2, average vessel diameter, vessel area percentage, vessel element length, percentages of perforation plate types, transpiration rate, stomatal conductance, leaf area, leaf thickness, leaf dry mass per unit leaf area, stomatal density and stomatal pore length were measured. Vessel number per mm2, vessel area percentage, stomatal conductance, transpiration rate, leaf thickness and leaf dry mass per unit leaf area showed a significant negative correlation with yearly, winter, spring and autumn precipitation. The majority of the studied characteristics were not related to the mean annual and seasonal temperatures of the original provenances. The results suggest that anatomical characteristics of vessel elements and different foliar traits in Fagus crenata are mainly influenced by the precipitation of the origins.

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