scholarly journals Bacterial Inhibition on Beauveria bassiana Contributes to Microbiota Stability in Delia antiqua

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangyuan Zhou ◽  
Yunxiao Gao ◽  
Mei Liu ◽  
Letian Xu ◽  
Xiaoqing Wu ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Mycelial Growth ◽  
Bacterial Species ◽  
Management Strategies ◽  
Underlying Mechanism ◽  
Conidial Germination ◽  
Delia Antiqua ◽  
Bacterial Microbiota ◽  
Fungal Microbiota ◽  
Microbial Environment

Given the multiple roles of associated microbiota in improving animal host fitness in a microbial environment, increasing numbers of researchers have focused on how the associated microbiota keeps stable under complex environmental factors, especially some biological ones. Recent studies show that associated microbiota interacts with pathogenic microbes. However, whether and how the interaction would influence microbiota stability is limitedly investigated. Based on the interaction among Delia antiqua, its associated microbiota, and one pathogen Beauveria bassiana, the associated microbiota's response to the pathogen was determined in this study. Besides, the underlying mechanism for the response was also preliminarily investigated. Results showed that B. bassiana neither infect D. antiqua larvae nor did it colonize inside the associated microbiota, and both the bacterial and fungal microbiota kept stable during the interaction. Further experiments showed that bacterial microbiota almost completely inhibited conidial germination and mycelial growth of B. bassiana during its invasion, while fungal microbiota did not inhibit conidial germination and mycelial growth of B. bassiana. According to the above results, individual dominant bacterial species were isolated, and their inhibition on conidial germination and mycelial growth of B. bassiana was reconfirmed. Thus, these results indicated that bacterial instead of fungal microbiota blocked B. bassiana conidia and stabilized the associated microbiota of D. antiqua larvae during B. bassiana invasion. The findings deepened the understanding of the role of associated microbiota–pathogen microbe interaction in maintaining microbiota stability. They may also contribute to the development of novel biological control agents and pest management strategies.

scholarly journals Evaluation of Fungicides and Management Strategies against Cercospora Leaf Spot of Olive Caused by Pseudocercospora cladosporioides

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 271
Author(s):  
Joaquín Romero ◽  
Arantxa Ávila ◽  
Carlos Agustí-Brisach ◽  
Luis F. Roca ◽  
Antonio Trapero
Keyword(s):  
Leaf Spot ◽  
Mycelial Growth ◽  
Management Strategies ◽  
Conidial Germination ◽  
Field Conditions ◽  
Cercospora Leaf Spot ◽  
Wide Range ◽  
Traditional Strategy ◽  
Mediterranean Conditions

Cercospora leaf spot of olive (CLSO), caused by Pseudocercospora cladosporioides, is one of the most important foliar diseases of olives worldwide. This study aimed to evaluate the effect of a wide range of fungicides on mycelial growth and conidial germination of P. cladosporioides in vitro, and to evaluate the effect of several fungicides, application timings and management strategies (conservative and risky) to control CLSO under field conditions. Of the studied fungicides, strobilurin compounds and benomyl were the most effective active ingredients, followed by folpet, captan and maneb, in inhibiting mycelial growth and conidial germination. The pyraclostrobin + boscalid treatment was effective under field conditions, even without the application of supplementary copper. Treatments conducted in October or March were more effective than those conducted in May. Management strategies based on the author’s experience reduced copper applications up to 32.0% and 50.0% (conservative and risky strategy, respectively) in comparison to the reduction with the traditional strategy, without increasing CLSO incidence. This work provides useful information about effective formulations against CLSO and a reduction in unnecessary fungicide applications in an effort to implement IPM in olive orchards under Mediterranean conditions.

Evaluation of Fungicides to Control Loquat Scab Caused by Fusicladium eriobotryae

2014 ◽  
Vol 15 (3) ◽  
pp. 88-91 ◽  
Author(s):  
Elisa González-Domínguez ◽  
José M. Rodríguez-Reina ◽  
José García-Jiménez ◽  
Josep Armengol
Keyword(s):  
Disease Control ◽  
Disease Severity ◽  
Ammonium Chloride ◽  
Post Infection ◽  
Mycelial Growth ◽  
Management Strategies ◽  
Conidial Germination ◽  
Copper Oxychloride

Loquat scab caused by Fusicladium eriobotryae is the main disease affecting the loquat crop. The fungus can infect leaves and fruits, reducing the marketable quality of the latter. The efficacy of 13 fungicides against F. eriobotryae was evaluated in vitro by testing their effect on mycelial growth and conidial germination. Boscalid, chlorothalonil, didecyldimethyl ammonium chloride, and pyraclostrobin were able to reduce both conidial germination and mycelial growth of F. eriobotryae. Moreover, a growth chamber experiment was conducted to determine the pre- and post-infection activity of five selected fungicides. Difenoconazole and pyraclostrobin applications resulted in relative disease severity (RDS) values lower than 5%, even when applied 7 days before or after the inoculation. Boscalid and mancozeb applied before F. eriobotryae inoculation resulted in RDS values lower than 15%, whereas values up to 20% of RDS were obtained with copper oxychloride. Results indicate that the fungicides currently recommended in southeastern Spain against loquat scab provide adequate disease control, and new active ingredients could be added to the present management strategies. Accepted 7 May 2014. Published 27 July 2014.

Influence of different temperature and relative humidity levels on the mycelial growth, conidial germination and anthracnose incidence of Colletotrichum gloeosporioides

1970 ◽  
pp. 31
Author(s):  
R. UDHAYAKUMAR
Keyword(s):  
Relative Humidity ◽  
Mycelial Growth ◽  
Room Temperature ◽  
Colletotrichum Gloeosporioides ◽  
Disease Incidence ◽  
Management Strategies ◽  
Conidial Germination ◽  
Relative Humidity Level ◽  
Humidity Level ◽  
Temperature Levels

Mango anthracnose caused by Colletotrichum gloeosporioides is a highly destructive pathogen that causes considerable damage, inflicting severe qualitative and quantitative losses. Among the external factors which influence the growth of fungi, temperature and relative humidity plays an important role. Each pathogen has got its own cardinal temperature and relative humidity, also understanding about these factors will help to standardize the management strategies. Among the six temperature levels tested, 25°C was found to be more conducive for the mycelial growth (88.33 mm), conidial germination (69.00%) of C. gloeosporioides, and maximum disease development (97.00 %) which was followed by room temperature (28+2°C).The maximum disease incidence of 97.00 per cent in the fruits was recorded at 25oC followed by room temperature (28±2oC) (83.33 %) after 10 days of inoculation. Among the seven relative humidity levels tested, the maximum mycelial growth (87.00 mm), conidial germination (72.00%) and maximum disease incidence (97.00 %) was recorded at 100 per cent relative humidity, which was followed by 92.9% relative humidity level (83.00 mm; 61.67% mycelial growth and conidia germination, respectively). The least mycelial growth (7.33 mm) and conidial germination (0.0%) was recorded at 36.8% relative humidity level.

DIVERSITY OF CULTURABLE BACTERIAL MICROBIOTA OF THE Eisenia foetida DIGESTIVE TRACT

2018 ◽  
Vol 41 (3) ◽  
pp. 255-264 ◽  
Author(s):  
J. Abraham Pérez-Pérez ◽  
David Espinosa-Victoria ◽  
Hilda V. Silva-Rojas ◽  
Lucía López-Reyes
Keyword(s):  
Bacterial Diversity ◽  
Digestive Tract ◽  
Bacterial Species ◽  
Brain Heart Infusion ◽  
Rrna Gene ◽  
Eisenia Foetida ◽  
Bacterial Isolates ◽  
Bacterial Microbiota ◽  
Decomposition Of Organic Matter ◽  
Earthworm Gut

Bacteria are an unavoidable component of the natural earthworm diet; thus, bacterial diversity in the earthworm gut is directly linked to decomposition of organic matter and development of the surrounding plants. The aim of this research was to isolate and to identify biochemically and molecularly the culturable bacterial microbiota of the digestive tract of Eisenia foetida. Earthworms were sourced from Instituto de Reconversión Productiva y Bioenergética (IRBIO) and Colegio de Postgraduados (COLPOS), México. Bacterial isolation was carried out on plates of Brain Heart Infusion (BHI) culture medium. Fifty six and 44 bacterial isolates were obtained from IRBIO and COLPOS, respectively. The population was composed of 44 Gram-negative and 56 Gram-positive isolates. Over 50 % of the bacterial isolates were rod-shaped cells. The 16S rRNA gene was sequenced and nine genera were identified in worms from IRBIO (Bacillus, Paenibacillus, Solibacillus, Staphylococcus, Arthrobacter, Pantoea, Stenotrophomonas, Acinetobacter and Aeromonas) and six in worms from COLPOS (Bacillus, Paenibacillus, Stenotrophomonas, Staphylococcus, Acinetobacter and Aeromonas). Bacillus was the predominant genus, with eight and six species in the oligochaetes from IRBIO and COLPOS, respectively. The most represented bacteria in the worms from both sites were Bacillus sp. and B. subtilis. The predominance of Bacillus was probably due to spore formation, a reproductive strategy that ensures survival and dispersion in the soil and oligochaetes digestive tract. The gut of E. foetida not only harbored bacterial species of agronomic importance but also species potentially pathogenic for humans (Staphylococcus warneri, Pantoea agglomerans and Stentrophomonas sp.). The larger bacterial diversity in worms from IRBIO could be due to their feeding on cattle manure, which is a rich source of bacteria.

scholarly journals Trends in Molecular Diagnosis and Diversity Studies for Phytosanitary Regulated Xanthomonas

2021 ◽  
Vol 9 (4) ◽  
pp. 862
Author(s):  
Vittoria Catara ◽  
Jaime Cubero ◽  
Joël F. Pothier ◽  
Eran Bosis ◽  
Claude Bragard ◽  
...  
Keyword(s):  
Molecular Diagnosis ◽  
Bacterial Species ◽  
Management Strategies ◽  
Diagnostic Methods ◽  
Plant Diseases ◽  
Wild Plants ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Wide Range ◽  
Diversity Studies

Bacteria in the genus Xanthomonas infect a wide range of crops and wild plants, with most species responsible for plant diseases that have a global economic and environmental impact on the seed, plant, and food trade. Infections by Xanthomonas spp. cause a wide variety of non-specific symptoms, making their identification difficult. The coexistence of phylogenetically close strains, but drastically different in their phenotype, poses an added challenge to diagnosis. Data on future climate change scenarios predict an increase in the severity of epidemics and a geographical expansion of pathogens, increasing pressure on plant health services. In this context, the effectiveness of integrated disease management strategies strongly depends on the availability of rapid, sensitive, and specific diagnostic methods. The accumulation of genomic information in recent years has facilitated the identification of new DNA markers, a cornerstone for the development of more sensitive and specific methods. Nevertheless, the challenges that the taxonomic complexity of this genus represents in terms of diagnosis together with the fact that within the same bacterial species, groups of strains may interact with distinct host species demonstrate that there is still a long way to go. In this review, we describe and discuss the current molecular-based methods for the diagnosis and detection of regulated Xanthomonas, taxonomic and diversity studies in Xanthomonas and genomic approaches for molecular diagnosis.

Repressed Beauveria bassiana infections in Delia antiqua due to associated microbiota

2018 ◽  
Vol 75 (1) ◽  
pp. 170-179 ◽  
Author(s):  
Fangyuan Zhou ◽  
Xiaoqing Wu ◽  
Letian Xu ◽  
Shuhai Guo ◽  
Guanhong Chen ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Delia Antiqua

Detection of oomycide-insensitive Phytophthora isolates in Maryland ornamental nurseries and Mid-Atlantic landscapes provide data for reconsidering management strategies

2021 ◽  
Author(s):  
Justine Beaulieu ◽  
Johanna Del Castillo Munera ◽  
Yilmaz Balci
Keyword(s):  
Growth Rate ◽  
Mycelial Growth ◽  
Management Strategies ◽  
Resistance Management ◽  
Phytophthora Species ◽  
Oak Forests ◽  
Relative Growth ◽  
Off Label ◽  
Potting Media ◽  
Almost All

Five Phytophthora species comprising a total of 243 isolates (77 P. cinnamomi, 23 P. citrophthora, 18 P. multivora, 18 P. pini, and 107 P. plurivora) were screened for sensitivity to mefenoxam, fosetyl-Al, dimethomorph, dimethomorph + ametoctradin and fluoxastrobin using amended agar assays. Mefenoxam-insensitive isolates were detected within P. cinnamomi (4%), P. multivora (11%), and P. plurivora (12%) even at approximately 2.5x the recommended label rate. These isolates were also insensitive to higher (off-label) concentrations of fluoxastrobin. Concentrations of dimethomorph (400 g/mL) and dimethomorph + ametoctradin (100 g/mL) were mostly effective in mycelial growth inhibition, but two P. plurivora isolates were insensitive, suggesting that resistance management is required. All mefenoxam-insensitive isolates were sensitive to fosetyl-Al at the label rate. Surprisingly, the populations of P. cinnamomi from mid-Atlantic oak forests included insensitive isolates. With almost all species, isolates recovered from asymptomatic hosts (e.g., soil/potting media collected of randomly selected asymptomatic hosts) had a significantly greater relative growth rate when compared to isolates recovered from symptomatic hosts (e.g., isolates recovered from lesions or wilted plants). These findings suggest that mefenoxam should no longer be used to manage oomycetes in Maryland ornamental nurseries and that the use of fluoxastrobin should be limited.

Sensitivity of C. fructicola and C. siamense of peach in China to multiple classes of fungicides and characterization of pyraclostrobin-resistant isolates

Plant Disease ◽  
2021 ◽  
Author(s):  
Hafiz Muhammad Usman ◽  
Qin Tan ◽  
Mohammad Mazharul Karim ◽  
Muhammad Adnan ◽  
Weixiao Yin ◽  
...  
Keyword(s):  
High Resistance ◽  
Mycelial Growth ◽  
Management Strategies ◽  
Cross Resistance ◽  
Qoi Fungicides ◽  
Quinone Outside Inhibitor ◽  
Dmi Fungicides ◽  
Colletotrichum Gloeosporioides Species Complex ◽  
Cyt B Gene

Anthracnose, mainly caused by Colletotrichum gloeosporioides species complex including C. fructicola and C. siamense, is a devastating disease of peach. The chemical control has been widely used for years and management failures have increased towards commonly used fungicides. Therefore, screening of sensitivity of Colletotrichum spp. to fungicides with different modes of action is needed to make proper management strategies for peach anthracnose. In this study, sensitivity of 80 isolates of C. fructicola and C. siamense was screened for pyraclostrobin, procymidone, prochloraz and fludioxonil based on mycelial growth inhibition at discriminatory doses. Results showed that C. fructicola and C. siamense isolates were highly resistant to procymidone and fludioxonil with 100% resistance frequencies to both fungicides, but sensitive to prochloraz, i.e., no resistant isolates were found. For pyraclostrobin, 74% of C. fructicola isolates showed high resistance and 26 % were low resistant, all of the C. siamense isolates were low resistant. No positive cross-resistance was observed between pyraclostrobin and azoxystrobin, even they are members of the same quinone outside inhibitor (QoI) fungicide group, and between pyraclostrobin and non-QoIs. Resistant isolates to QoI fungicides were evaluated for the fitness penalty. Results showed that no significant differences except for mycelial growth rates were detected between highly resistant and low-resistant isolates of C. fructicola. Molecular characterization of Cyt b gene revealed that the G143A point mutation was the determinant of the high resistance in C. fructicola. This study demonstrated the current resistance status of C. fructicola and C. siamense to different fungicides and their future perspectives. Demethylation inhibitor (DMI) fungicides are the best option among different chemicals to control peach anthracnose in China.

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