Effects of equilibrium relative humidity on in vitro growth of Botrytis cinerea and Alternaria alternata

1996 ◽  
Vol 36 (3) ◽  
pp. 383 ◽  
Author(s):  
S Alam ◽  
D Joyce ◽  
A Wearing
Keyword(s):  
Relative Humidity ◽  
Liquid Medium ◽  
Botrytis Cinerea ◽  
Alternaria Alternata ◽  
Mycelial Growth ◽  
Dry Matter ◽  
Diameter Growth ◽  
Colony Diameter ◽  
Equilibrium Relative Humidity

Mycelial growth in vitro of 2 fungal pathogens responsible for postharvest loss of horticulture produce, Botrytis cinerea and Alternaria alternata, was related to equilibrium relative humidity (e.r.h) at ambient temperature (20�C) using solutes to adjust the 'osmotic water potential' of the growth medium. Colony diameter growth of B. cinerea and A. alternata on solid medium (1/2 potato dextrose agar) was initially stimulated slightly when the e.r.h. was decreased from 99.7 (unamended medium) to 99.3% (-0.4 to -1.0 MPa). Thereafter, colony diameter growth continually decreased as a function of reducing e.r.h. over the range 99.3-94.3% e.r.h. (-1.0 to -8.0 MPa). Similar trends were recorded with both pathogens for their dry matter growth in liquid medium (Oxoid Czapek Dox) as a function of osmotic potential. Initial stimulation of dry matter growth at -1.0 MPa (equivalent to 99.3% e.r.h.) was not evident in liquid medium. Fungal growth data suggest that postharvest mycelial growth of Botrytis cinerea and Alternaria alternata on wounds, senescing tissue or secretions such as cell sap or nectar could be restricted through control of e.r.h. in packages of horticulture produce.

An Attempt at Biological Control of Blossom Blight of Rose Caused by Botrytis cinerea Using some Local Trichoderma spp. Strains

2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Limiting Factor ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Khuzestan Province ◽  
Inhibitory Potential ◽  
Cut Rose

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.

scholarly journals AVALIAÇÃO DO REAL POTENCIAL INIBIDOR DE EXTRATOS ETANÓLICOS DE Ottonia martiana SOBRE Cylindrocladium spathulatum E Botrytis cinerea

FLORESTA ◽  
2013 ◽  
Vol 43 (2) ◽  
pp. 225
Author(s):  
Miriam Machado Cunico ◽  
Celso Garcia Auer ◽  
Marlon Wesley Machado Cunico ◽  
Obdulio Gomes Miguel ◽  
Patricio Peralta Zamora ◽  
...  
Keyword(s):  
Factorial Design ◽  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Black Spot ◽  
Gray Mold ◽  
Causal Agent ◽  
In Vitro Testing ◽  
Ethanolic Extracts ◽  
Antifungal Potential

 Extratos etanólicos de anestesia, Ottonia martiana Miq., foram reavaliados quanto à inibição do crescimento micelial dos fungos Cylindrocladium spathulatum (pinta-preta da erva-mate) e Botrytis cinerea (mofo-cinzento do eucalipto), por meio do planejamento fatorial. A ocorrência de decomposição de bioativos no processo de autoclavagem também foi investigada, por meio de teste de eficiência de extratos filtrados (filtro Millipore) e esterilizados (autoclave) no controle dos fitopatógenos, nas concentrações de 1, 10, 100 e 1000 ppm. Os extratos etanólicos filtrado e esterilizado inibiram o crescimento micelial dos fungos e foram mais ativos frente a B. cinerea.O extrato filtrado exibiu maior potencial antifúngico que o extrato esterilizado. O processo de esterilização por autoclavagem causou pequena decomposição dos bioativos presentes no extrato de anestesia.Palavras-chave: Anestesia; mofo-cinzento; pinta-preta. Abstract Fungitoxic potential of ethanolic extracts of anestesia in the control of phytopathogenic diseases. The antifungal potential of anestesia, Ottonia martiana Miq. was reassessed by factorial design, in vitro testing of fungal mycelial growth compared to the pathogenic isolates Cylindrocladium spathulatum, causal agent of black spot onyerba mate, and Botrytis cinerea causal agent of gray-mold on eucalypts. Occurrence of decomposition of bioactive of the autoclaving process was investigated using foliar detached test compared to the pathogens (1000 ppm). Ethanolic extracts - EBEtOH (filtered and autoclaved) inhibited the mycelial growth of C. spathulatum and B. cinerea (1000 ppm) and were more pronounced against B. cinerea (43.6 % and 68.9 %). EBEtOH filtered (0.22 µm) presented higher activity than EBEtOH autoclaved (C. spathulatum: 52.8 % and 43.6 %, B. cinerea: 68.9 % and 43.6 %), suggesting little decomposition ofbioactive after autoclaving. EBEtOH filtrate presented potential inhibition of 28 % in eucalypt leaves against B. cinerea.  Keywords: Ottonia martiana; black spot; gray-mold.

scholarly journals Saprophytic microorganisms with potential for biological control of Botrytis cinerea on Geraldton waxflower flowers

2001 ◽  
Vol 41 (5) ◽  
pp. 697 ◽  
Author(s):  
D. R. Beasley ◽  
D. C. Joyce ◽  
L. M. Coates ◽  
A. H. Wearing
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Germ Tube ◽  
Conidial Germination ◽  
Pseudomonas Sp ◽  
Trichoderma Spp ◽  
Fusarium Sp ◽  
Flower Abscission ◽  
Germ Tube Elongation

Saprophytic bacteria, yeasts and filamentous fungi were isolated from Geraldton waxflower flowers and screened to identify potential antagonism towards Botrytis cinerea. Isolates from other sources (e.g. avocado) were also tested. Isolates were initially screened in vitro for inhibition of B. cinerea conidial germination, germ tube elongation and mycelial growth. The most antagonistic bacteria, yeasts and fungi were selected for further testing on detached waxflower flowers. Conidia of the pathogen were mixed with conidia or cells of the selected antagonists, co-inoculated onto waxflower flowers, and the flowers were sealed in glass jars and incubated at 20˚C. The number of days required for the pathogen to cause flower abscission was determined. The most antagonistic bacterial isolate, Pseudomonas sp. 677, significantly reduced conidial germination and retarded germ tube elongation of B. cinerea. None of the yeast or fungal isolates tested was found to significantly reduce conidial germination or retard germ tube elongation, but several significantly inhibited growth of B. cinerea. Fusarium sp., Epicoccum sp. and Trichoderma spp. were the most antagonistic of these isolates. Of the isolates tested on waxflower, Pseudomonas sp. 677 was highly antagonistic towards B. cinerea and delayed waxflower abscission by about 3 days. Trichoderma harzianum also significantly delayed flower abscission. However, as with most of the fungal antagonists used, inoculation of waxflower flowers with this isolate resulted in unsightly mycelial growth.

scholarly journals Response of Two Fungi in the Apple Sooty Blotch Complex to Temperature and Relative Humidity

2000 ◽  
Vol 90 (4) ◽  
pp. 362-367 ◽  
Author(s):  
Eric M. Johnson ◽  
Turner B. Sutton
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Mycelial Growth ◽  
Agar Culture ◽  
Air Drying ◽  
Sooty Blotch ◽  
Conidial Viability

Peltaster fructicola and Leptodontium elatius, two of the causal fungi of apple sooty blotch, responded differently to temperature and relative humidity in vitro. Conidia of L. elatius germinated from 12 to 32°C at relative humidities ≥97%, whereas conidia of P. fructicola germinated from 12 to 24°C at relative humidities ≥95%. Germination of conidia of L. elatius was optimum at 32°C and 99% relative humidity compared with 24°C and 97 or 99% relative humidity for P. fructicola. When L. elatius and P. fructicola were grown in Parafilm culture, sporulation was greatest at relative humidities of 97 to 99%. In agar culture, mycelia of L. elatius expanded radially from 12 to 32°C, and that of P. fructicola at 12 to 28°C. Mycelia of P. fructicola did not survive exposure for 7 days or more to temperatures ≥32°C. Mycelial growth was inhibited at relative humidities <95% for both fungi and no growth occurred at 88% relative humidity. Conidia of P. fructicola were more sensitive to air drying than were those of L. elatius. Conidial viability of P. fructicola was reduced significantly after 8 h of air drying and nearly completely inhibited after 12 h. Conidia of L. elatius required 24 h of air drying before a significant reduction in conidial viability was observed. These results support the hypothesis that environmental factors influence the temporal and geographical distributions of the fungi associated with the apple sooty blotch disease.

scholarly journals Effects of SHAM on the Sensitivity of Sclerotinia sclerotiorum and Botrytis cinerea to QoI Fungicides

Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1884-1888 ◽  
Author(s):  
Hongjie Liang ◽  
Jinli Li ◽  
Chaoxi Luo ◽  
Jianhong Li ◽  
Fu-Xing Zhu
Keyword(s):  
Botrytis Cinerea ◽  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
Control Efficacy ◽  
Vitro Assay ◽  
Qoi Fungicides ◽  
Quinone Outside Inhibitor ◽  
Fungal Phytopathogens ◽  
The Ideal

It is a common practice to add salicylhydroxamic acid (SHAM) into artificial medium in the in vitro sensitivity assay of fungal phytopathogens to the quinone outside inhibitor (QoI) fungicides. The rationale for adding SHAM is to inhibit fungal alternative oxidase, which is presumed to be inhibited by secondary metabolites of plants. Therefore, the ideal characteristics of SHAM should be almost nontoxic to phytopathogens and have no significant effect on control efficacy of fungicides. However, this study showed that the average effective concentration for 50% inhibition (EC50) of mycelial growth values of SHAM were 97.5 and 401.4 μg/ml for Sclerotinia sclerotiorum and Botrytis cinerea, respectively. EC50 values of the three QoI fungicides azoxystrobin, kresoxim-methyl, and trifloxystrobin in the presence of SHAM at 20 and 80 μg/ml for S. sclerotiorum and B. cinerea, respectively, declined by 52.7 to 78.1% compared with those without SHAM. For the dicarboximide fungicide dimethachlone, the average EC50 values in the presence of SHAM declined by 18.2% (P = 0.008) for S. sclerotiorum and 35.9% (P = 0.012) for B. cinerea. Pot experiments showed that SHAM increased control efficacy of the three QoI fungicides against the two pathogens by 43 to 83%. For dimethachlone, SHAM increased control efficacy by 134% for S. sclerotiorum and 86% for B. cinerea. Biochemical studies showed that SHAM significantly inhibited peroxidase activity (P = 0.024) of B. cinerea and esterase activity (P = 0.015) of S. sclerotiorum. The strong inhibitions of SHAM per se on mycelial growth of B. cinerea and S. sclerotiorum and significant influences on the sensitivity of the two pathogens to both the QoI fungicides and dimethachlone as well as inhibitions on peroxidase and esterase indicate that SHAM should not be added in the in vitro assay of sensitivity to the QoI fungicides.

scholarly journals Sodium Silicate Reduces Postharvest Decay on Hami Melons: Induced Resistance and Fungistatic Effects

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 279-283 ◽  
Author(s):  
Y. Bi ◽  
S. P. Tian ◽  
Y. R. Guo ◽  
Y. H. Ge ◽  
G. Z. Qin
Keyword(s):  
Sodium Silicate ◽  
Induced Resistance ◽  
Alternaria Alternata ◽  
Cucumis Melo ◽  
Mycelial Growth ◽  
Room Temperature ◽  
Post Inoculation ◽  
Fusarium Semitectum ◽  
Cucumis Melo L

The effect of sodium silicate (Si) for control of decay was tested in Hami melons (Cucumis melo L. var. inodorus Jacq.). Si significantly inhibited mycelial growth of Alternaria alternata, Fusarium semitectum, and Trichothecium roseum in vitro. Si at 100 mM was more effective than Si at 25 or 50 mM at controlling the diseases caused by the three pathogens, whereas Si at 200 mM was phytotoxic. Si treatments applied at 100 mM pre-inoculation with T. roseum had lower decay incidence and severity than treatments applied post-inoculation. The protection of Si was correlated with the activation of two families of defense-related enzymes, peroxidase and chitinase. Accumulation of both enzymes was induced in fruit treated with Si and challenged by T. roseum 24 h later, and was sustained for at least 9 days in ‘New Queen’ and 10 days in ‘8601’ at room temperature. It appeared that induced resistance was an important mechanism of disease control in Hami melons treated with Si.

scholarly journals In vitro study of baseline sensitivity of important fungi against different fungicides

2012 ◽  
Vol 4 (2) ◽  
pp. 264-265 ◽  
Author(s):  
Sanjay Goswami ◽  
R. Kaur ◽  
Dipak T. Nagrale
Keyword(s):  
Botrytis Cinerea ◽  
Alternaria Alternata ◽  
In Vitro Study ◽  
Phytopathogenic Fungi ◽  
Plant Diseases ◽  
Baseline Sensitivity ◽  
Resistance Development ◽  
Gloeosporium Ampelophagum ◽  
Mic Value

Baseline sensitivity values of important phytopathogenic fungi were studied against fungicides. ED50, ED90 and MIC value of propiconazole for, Colletotrichum capsici, and Gloeosporium ampelophagum was in the range of 0.020-0.04 μg/ml. ED50 values of tebuconazole for Alternaria alternata was 30.0 μg/ml. Azoxystrobin was also tested for its ED50, ED90 and MIC values against Alternaria alternata, C. capsici, G. ampelophagum and Botrytis cinerea where the values were in the range of 0.019-50.0, 0.03-60.0 and 0.2-100.0 μg/ml respectively. Baseline sensitivity values are important for the management of plant diseases and resistance development.

scholarly journals Effect of Ethanol Vapor Treatment on the Growth of Alternaria alternata and Botrytis cinerea and Defense-Related Enzymes of Fungi-Inoculated Blueberry During Storage

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaru Ji ◽  
Wenzhong Hu ◽  
Jia Liao ◽  
Zhilong Xiu ◽  
Aili Jiang ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Alternaria Alternata ◽  
Mycelial Growth ◽  
Ethanol Vapor ◽  
Defense Responses ◽  
Dependent Manner ◽  
Practical Application ◽  
Structure And Ultrastructure ◽  
Dose Dependent ◽  
Vapor Treatment

The aim of the present study was to investigate the effects of ethanol vapor on the inhibition of Alternaria alternata and Botrytis cinerea in postharvest blueberry and the induction of defense-related enzymes (DREs) activities in fungi-inoculated blueberries stored at 0±0.5°C for 16days. Results indicated that ethanol vapor markedly inhibited the mycelial growth of A. alternata and B. cinerea in a dose-dependent manner, with inhibition rates of 9.1% (250μlL−1), 36.4% (500μlL−1), and 5.5% (1,000μlL−1) on A. alternata and 14.2% (250μlL−1), 44.7% (500μlL−1), and 76.6% (1,000μlL−1) on B. cinerea, respectively. Meanwhile, ethanol vapor also enhanced the activities of DREs in fungi-inoculated blueberries, including β-1,3-glucanase (GLU), chitinase (CHI), phenylalnine ammonialyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO). In particular, 500μlL−1 ethanol vapor increased the activities of DREs by 84.7% (GLU), 88.0% (CHI), 37.9% (PAL), 85.5% (POD), and 247.0% (PPO) in A. alternata-inoculated blueberries and 103.8% (GLU), 271.1% (CHI), 41.1% (PAL), 148.3% (POD), and 74.4% (PPO) in B. cinerea-inoculated blueberries, respectively. But, the activity of PPO was decreased by 55.2 and 31.9% in 500μlL−1 ethanol-treated blueberries inoculated with A. alternata and B. cinerea, respectively, after 8days of storage. Moreover, the surface structure and ultrastructure of 500μlL−1 ethanol-treated blueberry fruit cells were more integrated than those of other treatments. The findings of the present study suggest that ethanol could be used as an activator of defense responses in blueberry against Alternaria and Botrytis rots, by activating DREs, having practical application value in the preservation of postharvest fruit and vegetables.

scholarly journals Antagonistic activity “in vitro” of some saprophytic fungi occurring on the phylloplane of rice, wheat and maize

2019 ◽  
Vol 3 (3) ◽  
Author(s):  
A. Mangiarotti ◽  
G. Del Frate ◽  
A. M. Picco ◽  
G. Caretta
Keyword(s):  
Botrytis Cinerea ◽  
Alternaria Alternata ◽  
Penicillium Chrysogenum ◽  
Fusarium Moniliforme ◽  
Antagonistic Activity ◽  
Pyricularia Oryzae ◽  
Gibberella Zeae ◽  
Aspergillus Clavatus ◽  
Stachybotrys Atra

Fue investigada la actividad antagónica in vitro de un total de 51 cepas pertenecientes a 16 géneros fúngicos detectados con mayor frecuencia en el filoplano del centeno, arroz y maíz.El antagonismo fue observado con el método de los cultivos duales en medios con agar, entre estos hongos y los fitopatógenos: Drechslera oryzae, Pyricularia oryzae y Helminthosporium maydis. Los más antagónicos son: Penicillium chrysogenum, P. thomii y Stachybotrys atra; ellos antagonizaron en particular con Botrytis cinerea, Fusarium moniliforme y Alternaria alternata. El antagonismo más exitoso contra los tres patógenos mencionados fue con P. chrysogenum y P. charlesii, quienes fueron notoriamente activos. Las cepas de Chaetomium globosum, Gibberella zeae, Fusarium moniliforme, Trichothecium roseum y B. cinerea presentan una actividad antagónica contra H. maydis; Cladosporium cladosporioides contra P. oryzae y D. oryzae; Aspergillus clavatus frente a D. oryzae. Los resultados son discutidos en relación al control biológico de estos patógenos de cereales

Sign in / Sign up

Export Citation Format

Share Document