Etiology of Septoria Leaf Spot of Pistachio in Southern Spain

Plant Disease ◽  
2021 ◽  
Author(s):  
Ana López-Moral ◽  
Carlos Agustí-Brisach ◽  
Maria Carmen Raya-Ortega ◽  
Maria Lovera ◽  
Carlos Trapero ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Mycelial Growth ◽  
Culture Media ◽  
Southern Spain ◽  
Effect Of Temperature ◽  
In Planta ◽  
Prevalent Disease ◽  
Specific Culture ◽  
Septoria Leaf Spot

Septoria leaf spot (SLS) is the most prevalent disease of pistachio (Pistacia vera L.) in Spain. To elucidate its etiology, 22 samples of pistachio leaves showing SLS symptoms were collected mainly from 1993 to 2018 across southern Spain. Affected leaves from terebinth (P. terebinthus) were also collected for comparative purposes. Six Septoria-like isolates were recovered from pistachio leaves. They were identified as Septoria pistaciarum by sequencing ITS, RPB2 and LSU genes. The phenotypic characteristics of conidia and colonies were evaluated, confirming the identity of S. pistaciarum. Conidia were solitary, hyaline, and straight to curved. Large differences in length were observed between conidia from leaf samples, with those from terebinth being slightly larger than those from pistachio. Colonies showed slow mycelial growth on PDA. The effect of temperature on conidial germination and mycelial growth was evaluated in vitro on PDA. For both characters, the optimum temperature was approximately 19-20°C. Eight culture media were tested, with oatmeal agar (OA) and Spezieller Nährstoffarmer agar (SNA) showing the highest mycelial growth and pistachio leaf agar (PLA) showing the highest sporulation. A specific culture medium integrating lyophilized-powdered pistachio leaves into diluted PDA improved sporulation in comparison with PLA. Pathogenicity tests were conducted by inoculating detached and in planta pistachio and terebinth leaflets with conidial suspensions. Typical symptoms of SLS and cirri of S. pistaciarum developed at 10 and 21 days after inoculation, respectively, in both hosts. This is the first report of S. pistaciarum causing SLS in pistachio and terebinth in Spain.

Vascular Fungi Associated with Branch Dieback of Olive in Super-High-Density Systems in Southern Spain

Plant Disease ◽  
2020 ◽  
Author(s):  
Carlos Agustí-Brisach ◽  
José Pablo Jiménez-Urbano ◽  
Maria Carmen Raya-Ortega ◽  
Ana López-Moral ◽  
Antonio Trapero-Casas
Keyword(s):  
Mycelial Growth ◽  
Culture Media ◽  
High Density ◽  
Southern Spain ◽  
Effect Of Temperature ◽  
Phaeomoniella Chlamydospora ◽  
Potted Plants ◽  
Pathogenicity Tests ◽  
Colony Color ◽  
Branch Dieback

Symptoms of branch dieback of olive with internal longitudinal dark streaking were observed during routine surveys in super high-density systems in southern Spain. Nineteen fungal isolates recovered from wood samples showing internal discoloration and necrotic xylem vessels were selected. Multilocus alignments of ITS, LSU, TUB and/or ACT were performed, and the following species were identified: Acremonium sclerotigenum, Cadophora luteo-olivacea, Paracremonium sp., Phaeoacremonium italicum, Ph. minimum, Ph. scolyti and Pseudophaeomoniella oleicola. Colony color, mycelial growth, conidial characteristics and production were defined on PDA, MEA and OA. Phenotypic characteristics and conidial production varied depending on the isolate and culture media. The effect of temperature on mycelial growth was evaluated on MEA. The isolates showed slowly mycelial growth (0.5-2.0 mm day-1), with the optimum temperature ranging from 23.2 to 33.9 °C. Pathogenicity tests were conducted on nine-month-old olive potted plants (‘Arbequina’) inoculated with mycelial plugs. Cadophora luteo-olivacea, Pm. minimum and Phaeomoniella chlamydospora isolates from grapevine were included in the pathogenicity tests for comparative purposes. Prior to inoculation, the effect on the infection by inoculating with conidial suspensions or mycelial plugs was evaluated, with the second method being the most effective. Cadophora luteo-olivacea was the most aggressive fungi to olive followed by Pm. minimum.

scholarly journals Dimorphism in Neopseudocercosporella capsellae, an Emerging Pathogen Causing White Leaf Spot Disease of Brassicas

2021 ◽  
Vol 11 ◽  
Author(s):  
Niroshini Gunasinghe ◽  
Martin J. Barbetti ◽  
Ming Pei You ◽  
Prabuddha Dehigaspitiya ◽  
Stephen Neate
Keyword(s):  
Leaf Spot ◽  
Culture Media ◽  
Control Measures ◽  
Effective Control ◽  
Leaf Spot Disease ◽  
In Planta ◽  
Artificial Culture ◽  
White Leaf ◽  
Yeast Phase

White leaf spot pathogen: Neopseudocercosporella capsellae causes significant damage to many economically important Brassicaceae crops, including oilseed rape through foliar, stem, and pod lesions under cool and wet conditions. A lack of information on critical aspects of the pathogen’s life cycle limits the development of effective control measures. The presence of single-celled spores along with multi-celled conidia on cotyledons inoculated with multi-celled conidia suggested that the multi-celled conidia were able to form single-celled spores on the host surface. This study was designed to demonstrate N. capsellae morphological plasticity, which allows the shift between a yeast-like single-celled phase and the multi-celled hyphal phase. Separate experiments were designed to illustrate the pathogen’s morphological transformation to single-celled yeast phase from multi-celled hyphae or multi-celled macroconidia in-vitro and in-planta. Results confirmed the ability of N. capsellae to switch between two morphologies (septate hyphae and single-celled yeast phase) on a range of artificial culture media (in-vitro) or in-planta on the host surface before infection occurs. The hyphae-to-yeast transformation occurred through the production of two morphologically distinguishable blastospore (blastoconidia) types (meso-blastospores and micro-blastospores), and arthrospores (arthroconidia).

scholarly journals Synthesis and Characterization of Novel Copper Nanoparticles for the Control of Leaf Spot and Anthracnose Diseases of Olive

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1667
Author(s):  
Panagiota Ntasiou ◽  
Alexandra Kaldeli Kerou ◽  
Theodora Karamanidou ◽  
Afrodite Vlachou ◽  
George T. Tziros ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Mycelial Growth ◽  
Crop Protection ◽  
Attenuated Total Reflection ◽  
Colletotrichum Acutatum ◽  
In Planta ◽  
Colletotrichum Spp ◽  
Type 3

Olive crop is frequently treated with copper fungicides to combat foliar and fruit diseases such as olive leaf spot caused by Fusicladium oleagineum and anthracnose caused by Colletotrichum spp. The replacement of copper-based products with more eco-friendly alternatives is a priority. Metal nanoparticles synthesized in several ways have recently revolutionized crop protection with applications against important crop pathogens. In this study, we present the development of four copper-based nanoparticles (CuNP Type 1 to 4) synthesized with a wet chemistry approach. The CuNPs were characterized using Transmission Electron Microscopy, Dynamic Light Scattering, Laser Doppler Electrophoresis, and Attenuated Total Reflection measurements. In addition, the activity of the four CuNP types was tested in vitro and in planta against F. oleagineum and Colletotrichum spp. In vitro sensitivity measurements showed that for both pathogens, mycelial growth was the most susceptible developmental stage to the tested compounds. Against both pathogens, CuNP Type 1 and Type 2 were found to be more active in reducing mycelial growth compared to the reference commercial compounds of copper oxide and copper hydroxide. In planta experiments showed that CuNP Type 3 and CuNP Type 4 exhibited a strong protectant activity against both F. oleagineum and Colletotrichum acutatum with control efficacy values significantly higher than those achieved by the applications of either reference product.

scholarly journals Evaluation of in-vitro methods to select effective streptomycetes against toxigenic fusaria

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6905 ◽  
Author(s):  
Elena Maria Colombo ◽  
Cristina Pizzatti ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Marco Saracchi ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Culture Media ◽  
Screening Methods ◽  
Dual Culture ◽  
In Planta ◽  
In Vitro Method ◽  
In Vitro Methods ◽  
Strain Diversity ◽  
Fungal Plant Pathogens

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.

scholarly journals  Leaf spot and dieback of Buxus caused by Cylindrocladium buxicola

2013 ◽  
Vol 49 (No. 4) ◽  
pp. 165-168 ◽  
Author(s):  
I. Šafránková ◽  
L. Holková ◽  
M. Kmoch
Keyword(s):  
Dna Sequencing ◽  
Leaf Spot ◽  
Mycelial Growth ◽  
Leaf Blight ◽  
Visual Symptoms ◽  
Buxus Sempervirens ◽  
Microscopic Features ◽  
South Moravia ◽  
Molecular Characters

Leaf blight symptoms were observed on potted box plants (Buxus sempervirens cv. Suffruticosa and B. microphylla) in a nursery in South Moravia in August 2010. These symptoms were suggestive of box blight on Buxus spp. Characteristics of the visual symptoms, microscopic features, and identification of the isolates using DNA sequencing are described. The causal agent was isolated and identified as Cylindrocladium buxicola Henricot by means of morphological, cultural, and molecular characters. The effect of five commercial fungicides on C. buxicola in vitro was studied. The most effective fungicides (kresoxim-methyl, azoxystrobin, and mancozeb) inhibited conidia germination and mycelial growth (kresoxim-methyl, myclobutanil, and penconazole) of C. buxicola more than 96%.  

Phosphite-based Products in the In vitro Colletotrichum musae Control

2019 ◽  
pp. 1-9
Author(s):  
Maria Luísa Mendes Rodrigues ◽  
Edson Hiydu Mizobutsi ◽  
Paola Junayra Lima Prates ◽  
Paula Virgínia Leite Duarte ◽  
Regina Cássia Ferreira Ribeiro ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Culture Medium ◽  
Culture Media ◽  
Petri Dish ◽  
State University ◽  
Randomized Design ◽  
Colletotrichum Musae ◽  
Study Laboratory ◽  
Vitro Effect

Aims: The aim of this study was to evaluate the in vitro effect of different phosphite formulations and concentrations on the development of Colletotrichum musae. Sample: to evaluate the inhibition of germination, mycelial growth and sporulation of Colletotrichum musae. Study Design:  Treatments were conducted in a completely randomized design, with 4 replicates, each replicate consisting of 1 Petri dish. Place and Duration of Study:  Laboratory of Post-Harvest Pathology, State University of Montes Claros, between March and October 2017. Methodology: Three different phosphite formulations were used: FCu1 (4% Cu + 20% P2O5), FCu2 (4% Cu + 22% P2O5) at concentrations of 0.5;1.0; 1.5 and 2.0 mL L-1 and FK (42% P2O5 + 27.7% K2O) at concentrations of 0.5; 1.0; 1.5 and 2.0 mg.L-1. Products were incorporated into the respective culture media. Culture medium alone and culture medium + imazalil were used as controls. Petri dishes were housed in BOD chamber at 25°C under a 12 hours photoperiod. Results: Results were submitted to analysis of variance and regression, and means were compared by the Tukey test (P <0.05). Control was compared to the other treatments by the Dunnet's test (P <0.05). Among the tested phosphite formulations, copper and potassium phosphites were found to reduce the mycelial growth of Colletotrichum musae. FCu2 presents a fungicide-like effect from the concentration of 0.5 m.L-1 in the control of conidia production. As for the FCu1, a fungicide-like effect was observed in the control of germination from the concentration of 1.5 mL.L-1. Conclusion: A significant fungistatic effect was observed between the concentrations of the products in the mycelial growth, sporulation and germination obtaining control of up to 100% of the development of C. musae. Copper phosphites were as effective as fungicide in inhibiting fungal development.

scholarly journals Inhibition of Phytophthora parasitica and P. capsici by Silver Nanoparticles Synthesized Using Aqueous Extract of Artemisia absinthium

2015 ◽  
Vol 105 (9) ◽  
pp. 1183-1190 ◽  
Author(s):  
Mohammad Ali ◽  
Bosung Kim ◽  
Kevin D. Belfield ◽  
David Norman ◽  
Mary Brennan ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Aqueous Extract ◽  
Dose Response ◽  
Mycelial Growth ◽  
Plant Pathogens ◽  
Synthesis Methods ◽  
In Planta ◽  
Artemisia Absinthium ◽  
Plant Disease Management

Application of nanoparticles for controlling plant pathogens is a rapidly emerging area in plant disease management, and nanoparticles synthesis methods that are economical and ecofriendly are extensively investigated. In this project, we investigated the potential of silver nanoparticles (AgNPs) synthesized with aqueous extract of Artemisia absinthium against several Phytophthora spp., which cause many economically important crop diseases. In in vitro dose-response tests conducted in microtiter plates, 10 µg ml−1 of AgNPs inhibited mycelial growth of P. parasitica, P. infestans, P. palmivora, P. cinnamomi, P. tropicalis, P. capsici, and P. katsurae. Detailed in vitro dose-response analyses conducted with P. parasitica and P. capsici revealed that AgNPs synthesized with A. absinthium extract were highly potent (IC50: 2.1 to 8.3 µg ml−1) and efficacious (100%) in inhibiting mycelial growth, zoospore germination, germ tube elongation, and zoospore production. Interestingly, AgNP treatment accelerated encystment of zoospores. Consistent with in vitro results, in planta experiments conducted in a greenhouse revealed that AgNP treatments prevented Phytophthora infection and improved plant survival. Moreover, AgNP in in planta experiments did not produce any adverse effects on plant growth. These investigations provide a simple and economical method for controlling Phytophthora with AgNP without affecting normal plant physiology.

scholarly journals PROSPECÇÃO E AVALIAÇÃO DO POTENCIAL BIOTECNOLÓGICO DE LINHAGENS COMERCIAIS DE SHIITAKE

2021 ◽  
Vol 35 (4) ◽  
pp. 640-649
Author(s):  
Dalvan Pereira Abilio ◽  
Olívia Gomes Martins ◽  
Giovana Silva ◽  
Meire Andrade
Keyword(s):  
Wheat Bran ◽  
Radial Growth ◽  
Mycelial Growth ◽  
Culture Medium ◽  
Lentinula Edodes ◽  
Culture Media ◽  
Biotechnological Potential ◽  
E Mail ◽  
Eucalyptus Sawdust

PROSPECÇÃO E AVALIAÇÃO DO POTENCIAL BIOTECNOLÓGICO DE LINHAGENS COMERCIAIS DE SHIITAKE   DALVAN PEREIRA ABÍLIO1, OLÍVIA GOMES MARTINS2, GIOVANA CRISTINA PINTO ALVES DA SILVA3, MEIRE CRISTINA NOGUEIRA DE ANDRADE4   1 Graduando em Ciências Biológicas, Centro Universitário Sagrado Coração – Unisagrado, R. Irmã Arminda, 10-50 - Jardim Brasil, 17011-160 Bauru, SP, Brasil. E-mail: [email protected] 2 Doutoranda em Agronomia – Energia na Agricultura, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista "Julio de Mesquita Filho" (UNESP), Av. Universitária, 3780 - Altos do Paraíso, 18610-034, Botucatu, SP, Brasil. E-mail: [email protected] 3 Mestre em Agronomia – Energia na Agricultura, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista "Julio de Mesquita Filho" (UNESP), Av. Universitária, 3780 - Altos do Paraíso, 18610-034, Botucatu, SP, Brasil. E-mail: [email protected] 4 Docente da Faculdade Gran Tietê, Av. 15 de Novembro, 125 - Centro, 17340-000, Barra Bonita, SP, Brasil. E-mail: [email protected]   RESUMO: O objetivo deste trabalho foi avaliar e comparar o crescimento micelial in vitro de quatro linhagens comerciais de Lentinula edodes (LE-241, LE-242, LE-243 e LE-244) em meio de cultura à base de serragem de eucalipto, suplementado com bagaço de malte ou farelo de trigo. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2x4 (substratos x linhgens), totalizando oito tratamentos, cada um com cinco repetições. Os substratos foram preparados com 20% de suplementação, acrescidos de calcário (tamponante), umidificados e esterilizados. Os meios de cultura foram preparados a partir da infusão dos substratos, filtração, adição de ágar e esterilização. As placas foram inoculadas com as linhagens e o crescimento radial do micélio na superfície do meio de cultura foi mensurado com paquímetro. O menor desenvolvimento micelial ocorreu com a linhagem LE-241 e com a linhagem LE-243 no substrato suplementado com farelo de trigo. Os maiores desenvolvimentos foram obtidos com as linhagens LE-242 e LE-244 no substrado suplementado com bagaço de malte. O desenvolvimento de todas as linhagens foi maior no substrato suplementado com bagaço de malte. Sendo assim, a utilização do bagaço de malte para o crescimento micelial é uma alternativa viável à suplementação tradicional com farelo de trigo.   Palavras-chave: fungos, cogumelo, Lentinula edodes, micélio, bagaço de malte.   PROSPECTING AND EVALUATING THE BIOTECHNOLOGICAL POTENTIAL OF SHIITAKE COMMERCIAL STRAINS   ABSTRACT: This study aimed to evaluate and compare the in vitro mycelial growth of four commercial Lentinula edodes strains (LE-241, LE-242, LE-243 and LE-244) in a culture medium based on eucalyptus sawdust, supplemented with malt bagasse or wheat bran. The experimental design was completely randomized, in a 2x4 factorial scheme (substrates x strains), totaling eight treatments, each with five repetitions. The substrates were prepared with 20% supplementation, added with lime (buffer), humidified and sterilized. The culture media were prepared from the infusion of substrates, filtration, addition of agar and sterilization. The plates were inoculated with the strains and the radial growth of the mycelium on the surface of the culture medium was measured using a caliper. The smallest mycelial growth occurred with the LE-241 strain and with the LE-243 strain on the substrate supplemented with wheat bran. The greatest growths were obtained with the LE-242 and LE-244 strains in the substrate supplemented with malt bagasse. The development of all strains was greater in the substrate supplemented with malt bagasse. Therefore, the use of malt bagasse for mycelial growth is a viable alternative to traditional wheat bran supplementation.   Keywords: fungi, mushroom, Lentinula edodes, mycelium, malt bagasse.

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