Effect of Euphorbia pulcherrima Leaf and Inflorescence Extracts on Spore Germination of Alternaria solani

2014 ◽  
pp. 489-494
Author(s):  
Arti Goel ◽  
Kanika Sharma
Keyword(s):  
Spore Germination ◽  
Alternaria Solani ◽  
Euphorbia Pulcherrima

Antifungal activity of ajoene, a constituent of garlic (Allium sativum)

1990 ◽  
Vol 68 (6) ◽  
pp. 1354-1356 ◽  
Author(s):  
U. P. Singh ◽  
V. N. Pandey ◽  
K. G. Wagner ◽  
K. P. Singh
Keyword(s):  
Antifungal Activity ◽  
Fusarium Oxysporum ◽  
Spore Germination ◽  
Allium Sativum ◽  
Alternaria Solani ◽  
Field Conditions ◽  
Fusarium Udum ◽  
Alternaria Tenuissima ◽  
Fusarium Semitectum ◽  
Alternaria Sp

Ajoene, a compound derived from garlic (Allium sativum L.), inhibited spore germination of some fungi, namely, Alternaria solani, Alternaria tenuissima, Alternaria triticina, Alternaria sp., Colletotrichum sp., Curvularia sp., Fusarium lini, Fusarium oxysporum, Fusarium semitectum, and Fusarium udum, which cause serious diseases in some important crop plants in India. The compound was very effective in checking spore germination at a concentration of 25 μg/mL in some of the above fungi and, in most cases, there was 100% inhibition of germination at 100 μg/mL. It is quite likely that the compound may be useful in controlling disease(s) under field conditions.

scholarly journals A Microfluidic Assay for Identifying Differential Responses of Plant and Human Fungal Pathogens to Tobacco Phylloplanins

2014 ◽  
Vol 15 (3) ◽  
pp. 130-134
Author(s):  
Chakradhar Mattupalli ◽  
Joseph E. Spraker ◽  
Erwin Berthier ◽  
Amy O. Charkowski ◽  
Nancy P. Keller ◽  
...  
Keyword(s):  
Biological Activity ◽  
Spore Germination ◽  
Fungal Pathogens ◽  
Antimicrobial Properties ◽  
Alternaria Solani ◽  
Differential Sensitivity ◽  
Colletotrichum Coccodes ◽  
Fusarium Sambucinum ◽  
Germination Inhibition ◽  
Leaf Surfaces

Phylloplanins are defensive glycoproteins secreted onto leaf surfaces by trichome-bearing plants such as tobacco (Nicotiana tabacum). They are of interest because of their antimicrobial properties, but like other natural product bioactives, the assessment and screening of phylloplanins biological activity is impeded by limited availabilities of active compounds. Here we report an inexpensive microfluidic approach that requires ≤ 20 microliters of tobacco phylloplanins to assess spore germination inhibition of plant and human fungal pathogens. Spores of Colletotrichum coccodes and Aspergillus fumigatus suspended in solutions containing tobacco phylloplanins did not germinate at 48 and 30 h post-treatment, respectively. Tobacco phylloplanins transiently inhibited spore germination of Fusarium sambucinum, but had no detectable activity against Alternaria solani or Verticillium albo-atrum at the concentrations tested, demonstrating differential sensitivity of fungi to tobacco phylloplanins. 4 August 2014. 14 August 2014.

scholarly journals Fragments of a Wheat Hevein-Like Antimicrobial Peptide Augment the Inhibitory Effect of a Triazole Fungicide on Spore Germination of Fusarium oxysporum and Alternaria solani

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 870
Author(s):  
Larisa Shcherbakova ◽  
Tatyana Odintsova ◽  
Tatyana Pasechnik ◽  
Lenara Arslanova ◽  
Tatyana Smetanina ◽  
...  
Keyword(s):  
Spore Germination ◽  
Defense Mechanisms ◽  
Crop Protection ◽  
Alternaria Solani ◽  
Pathogenic Fungi ◽  
Inhibitory Effect ◽  
Structural Function ◽  
Triazole Fungicide ◽  
Alternaria Species

There are increasing environmental risks associated with extensive use of fungicides for crop protection. Hence, the use of new approaches using natural plant defense mechanisms, including application of plant antimicrobial peptides (AMPs), is of great interest. Recently, we studied the structural–function relationships between antifungal activity and five hevein-like AMPs from the WAMP (wheat AMP) family of Triticum kiharae Dorof. et Migush. We first discovered that short peptides derived from the central, N-, and C-terminal regions of one of the WAMPs (WAMP-2) were able to augment the inhibitory effect of Folicur® EC 250, a triazole fungicide, on spore germination of the wheat pathogenic fungi, including Fusarium spp. and Alternaria alternata. In this research, we explored the ability of chemically synthesized WAMP-2-derived peptides for enhancing the sensitivity of two other Fusarium and Alternaria species, F. oxysporum and A. solani, causing wilt and early blight of tomato, respectively, to Folicur®. The synthesized WAMP-2-derived peptides synergistically interacted with the fungicide and significantly increased its efficacy, inhibiting conidial germination at much lower Folicur® concentrations than required for the same efficiency using the fungicide alone. The experiments on co-applications of some of WAMP-2-fragments and the fungicide on tomato leaves and seedlings, which confirmed the results obtained in vitro, are described.

scholarly journals Parasitic Fitness of Fungicide-Resistant and -Sensitive Isolates of Alternaria solani

Plant Disease ◽  
2018 ◽  
Vol 102 (3) ◽  
pp. 666-673 ◽  
Author(s):  
Mitchell J. Bauske ◽  
Neil C. Gudmestad
Keyword(s):  
Spore Germination ◽  
Point Mutations ◽  
Alternaria Solani ◽  
The United States ◽  
Wild Type ◽  
Parasitic Fitness ◽  
Fitness Parameters ◽  
Multiple Chemical

Resistance to chemistries of the succinate dehydrogenase inhibiting (SDHI) and quinone outside inhibiting (QoI) fungicides has developed rapidly in populations of Alternaria solani, the cause of early blight of potato. Reduced sensitivity to the anilinopyrimidine (AP) fungicide pyrimethanil has also been identified recently, determining that resistance to three chemical classes of fungicides is present within the A. solani population. Although no mutations have been characterized to confer resistance to APs, in A. solani five point mutations on three AsSdh genes have been determined to convey resistance to SDHIs, and the substitution of phenylalanine with leucine at position 129 (F129L) in the cytb gene confers resistance to QoIs. The objective of this study was to investigate the parasitic fitness of A. solani isolates with resistance to one or more of these chemical classes. A total of 120 A. solani isolates collected from various geographical locations around the United States were chosen for in vitro assessment, and 60 of these isolates were further evaluated in vivo. Fitness parameters measured were (i) spore germination in vitro, (ii) mycelial expansion in vitro, and (iii) aggressiveness in vivo. No significant differences in spore germination or mycelial expansion (P = 0.44 and 0.51, respectively) were observed among wild-type and fungicide-resistant isolates in vitro. Only A. solani isolates possessing the D123E mutation were shown to be significantly more aggressive in vivo (P < 0.0001) compared with wild-type isolates. These results indicate that fungicide-resistant A. solani isolates have no significant fitness penalties compared with sensitive isolates under the parameters evaluated regardless of the presence or absence of reduced sensitivity to multiple chemical classes. Results of these studies suggest that A. solani isolates with multiple fungicide resistances may compete successfully with wild-type isolates under field conditions.

scholarly journals Shift in Sensitivity of Alternaria solani in Response to QoI Fungicides

Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 181-187 ◽  
Author(s):  
J. S. Pasche ◽  
C. M. Wharam ◽  
N. C. Gudmestad
Keyword(s):  
Disease Severity ◽  
Spore Germination ◽  
Early Blight ◽  
Alternaria Solani ◽  
Baseline Sensitivity ◽  
Qoi Fungicides ◽  
Cross Sensitivity ◽  
Significant Difference

Isolates of Alternaria solani, cause of potato early blight, collected in 1998 through 2001 from various potato growing areas across the midwestern United States, were tested for sensitivity to azoxystrobin. Isolates collected in 1998, prior to the introduction of azoxystrobin, were tested to establish the baseline sensitivity of the fungus to this fungicide. Isolates collected in subsequent years, not necessarily from the same sites as baseline isolates, were tested to determine if populations of A. solani had become less sensitive to azoxystrobin. Azoxystrobin sensitivity was determined utilizing an in vitro spore germination assay. The effective fungicide concentration that inhibited spore germination by 50% (EC50) was determined for each isolate. There was no significant difference in mean EC50 values between baseline isolates and all other isolates collected through 1999. Mean azoxystrobin EC50 values of A. solani isolates collected in 2000 and 2001 were significantly higher compared with means from previous years, and mean azoxystrobin EC50 values from 2001 were significantly higher than means from isolates collected in 2000. A subset of 54 A. solani isolates was evaluated in vitro for cross-sensitivity to pyraclostrobin and trifloxystrobin. A highly significant and strong correlation among the isolates tested for fungicide cross-sensitivity was detected between azoxystrobin and pyraclostrobin; however, the correlation between azoxystrobin and trifloxystrobin, and between trifloxystrobin and pyraclostrobin, was significant but weak. A second subset of five isolates was chosen for in vivo assessment of azoxystrobin, pyraclostrobin, and trifloxystrobin sensitivity. Disease severity on plants treated with azoxystrobin and pyraclostrobin was significantly greater with reduced-sensitive A. solani isolates compared with sensitive isolates. Disease severity was not statistically different between azoxystrobin reduced-sensitive and sensitive A. solani isolates on plants treated with trifloxystrobin. This is the first report of a shift in sensitivity to QoI fungicides in a fungus possessing only an anamorphic stage.

scholarly journals Fungicide Resistance of Two Species of Alternaria from Potato in the Columbia Basin of Washington

Plant Disease ◽  
2014 ◽  
Vol 98 (12) ◽  
pp. 1648-1653 ◽  
Author(s):  
Lydia Tymon ◽  
Dennis A. Johnson
Keyword(s):  
Spore Germination ◽  
Fungicide Resistance ◽  
Mycelial Growth ◽  
Alternaria Solani ◽  
Threshold Concentration ◽  
Brown Spot ◽  
Cellular Respiration ◽  
Columbia Basin ◽  
Growth Ratio ◽  
Fungal Populations

Fungicides are extensively used in the Columbia Basin of Washington in an effort to manage early blight and brown spot on potato caused by Alternaria solani and A. alternata, respectively. Azoxystrobin and boscalid interfere with cellular respiration, and fungicide resistance is expected to occur in fungal populations due to the narrow modes of action dictated by each fungicide. The objective of this research was to assess A. solani and A. alternata populations in the Columbia Basin of Washington for azoxystrobin and boscalid resistance by initially screening isolates at a threshold concentration using mycelial growth and spore germination. Fifty isolates of A. solani and 58 of A. alternata were randomly selected for screening from 671 isolates collected from potato in the Columbia Basin from 2009 to 2011. Screening at a threshold concentration was done to estimate the range of fungicide resistance within the populations of A. solani and A. alternata in the region. Resistance of five isolates that differed in sensitivity to azoxystrobin and boscalid were then assessed for mycelial growth and spore germination at three fungicide concentrations in order to determine where rates were no longer effective. A. solani mycelial growth ratios and percent spore germination on azoxystrobin-amended media did not change from 2010 to 2011. A slight decrease in resistance of mycelial growth to azoxystrobin was exhibited among A. alternata isolates collected between 2010 and 2011. No change in sensitivity to azoxystrobin was observed in mycelial growth ratios among A. alternata isolates collected between 2010 and 2011. Resistance to boscalid by A. solani increased as indicated by a significant increase in mean mycelial growth ratio from 2010 to 2011, whereas A. alternata showed no change. Spore germination of A. solani was less at 100 μg/ml than at 1 or 10 μg/ml azoxystrobin. Spore germination of A. alternata did not differ among 1, 10, or 100 μg/ml azoxystrobin. Spore germination of A. solani and A. alternata did not differ among 0.5, 5, or 50 μg/ml boscalid. Resistance to azoxystrobin and boscalid in A. solani and A. alternata populations was shown to be present in the Columbia Basin and will likely become widespread with continued used of site-specific fungicides.

THE FUNGICIDAL ACTIVITY OF METHYL BROMIDE

1959 ◽  
Vol 37 (1) ◽  
pp. 51-58 ◽  
Author(s):  
D. E. Munnecke ◽  
R. A. Ludwig ◽  
R. E. Sampson
Keyword(s):  
Vapor Pressure ◽  
Glass Fiber ◽  
Methyl Bromide ◽  
Spore Germination ◽  
Fungicidal Activity ◽  
Alternaria Solani ◽  
Glass Fiber Filter ◽  
Germination Medium ◽  
Fiber Filter

Spores of Alternaria solani carried on glass fiber filter disks were employed in a study of the fungicidal activity of the fumigant, methyl bromide. Following exposure to the fumigant the disks, carrying the spores, were placed in a spore germination medium and the results subsequently evaluated by direct mortality counts. Linear probit-log dose regression lines were obtained by this procedure. The effectiveness of the fumigant was found to be dependent on the vapor pressure of water in the atmosphere and to be independent of temperature. The results suggest that humidity operates through its effect on spore hydration.

Ximena, variedad de nochebuena (Euphorbia pulcherrima Willd. ex Klotzsch) para decorar espacios de interior

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Jaime Canul Ku ◽  
Faustino García-Pérez ◽  
Edwin J. Barrios-Gómez ◽  
Sandra E. Rangel-Estrada
Keyword(s):  
Euphorbia Pulcherrima

Objetivo: Describir la variedad de nochebuena Ximena en base a directrices de la UPOV y evaluar su comportamiento con un productor cooperante en el estado de Morelos.Diseño/metodología/aproximación: La variedad se generó mediante los métodos genotécnicos de hibridación, selección recurrente y uso de la técnica de injerto. La descripción varietal se realizó en base al documento de la Unión para la Protección de las Obtenciones Vegetales (UPOV). El diseño experimental utilizado fue un completamente al azar con 10 repeticiones. Se registraron caracteres vegetativos y de bráctea de la planta. La información se estudió mediante análisis de varianza y prueba de comparación de medias Tukey (P? 0.05).Resultados: Ximena presenta porte alto, de amplitud grande con ramificación intermedia. La hoja de forma oval, larga y ancha con peciolo de longitud media. Brácteas de forma elíptica, color rojo, sin torsión y rugosidad entre los nervios. La anchura de la cima es media, glándulas del ciatio de color amarillo de tamaño medio sin alguna deformación. La respuesta de Ximena fue estadísticamente similar a los dos testigos en diámetro del tallo, número de entrenudos, ancho de hoja, longitud de peciolo de hoja y bráctea. En cambio, fue superior estadísticamente en longitud de bráctea, amplitud de dosel de bráctea y diámetro de ciatio.Limitaciones del estudio/implicaciones: La variedad se mantiene como planta madre, a partir de la cual se van a establecer cultivos comerciales. Por lo que, requiere adecuada nutrición y condiciones que no permitan su diferenciación floral.Hallazgos/conclusiones: El comportamiento y arquetipo de Ximena fue comparable a la de variedades comerciales, posee características estéticas que demanda el mercado, puede ser competitiva y se considera candidata para diversificar la oferta de plantas de nochebuena en la temporada de navidad.

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