Isolation and identification of Arbutus unedo L. fungi endophytes and biological control of Phytophthora cinnamomi in vitro

PROTOPLASMA ◽  
2021 ◽  
Author(s):  
João Martins ◽  
Paula Veríssimo ◽  
Jorge Canhoto
Keyword(s):  
Biological Control ◽  
Phytophthora Cinnamomi ◽  
Isolation And Identification ◽  
Arbutus Unedo

scholarly journals Control of root rot (Phytophthora cinnamomi) in avocado (Persea Americana) with bioagents

2020 ◽  
Vol 46 (3) ◽  
pp. 205-211
Author(s):  
Ciro Hideki Sumida ◽  
Lucas Henrique Fantin ◽  
Karla Braga ◽  
Marcelo Giovanetti Canteri ◽  
Martin Homechin
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Persea Americana ◽  
Field Conditions ◽  
In Vitro Tests ◽  
Trichoderma Spp ◽  
Maize Cultivation ◽  
Antagonistic Potential

ABSTRACT Despite the favorable edaphoclimatic conditions for avocado production in Brazil, diseases such as root rot caused by the pathogen Phytophthora cinnamomi compromise the crop. With the aim of managing root rot in avocado, the present study aimed to evaluate chemical and biological control with isolates of Trichoderma spp. and Pseudomonas fluorescens. Thus, three assays were conducted to assess: (i) mycelial inhibition of P. cinnamomi by isolates of Trichoderma spp. and P. fluorescens from different crop systems; (ii) effect of autoclaved and non-autoclaved metabolites of P. fluorescens, and (iii) chemical or biological treatment of avocado seedlings on the control of root rot under field conditions. The isolates of Trichoderma spp. from maize cultivation soil and the commercial products formulated with Trichoderma presented greater antagonism (p <0.05) to the pathogen P. cinnamomi in the in vitro tests. Similarly, non-autoclaved metabolites of P. fluorescens presented antagonistic potential to control P. cinnamomi. Under field conditions, the fungicide metalaxyl and the bioagents showed effectiveness in controlling P. cinnamomi, as well as greater root length and mass. Results demonstrated potential for the biological control of avocado root rot with Trichoderma spp. and P. fluorescens.

scholarly journals Identification and Characterization of Arbutus Unedo L. Endophytic Bacteria Isolated From Wild and Cultivated Trees for the Biological Control of Phytophthora

2021 ◽  
Author(s):  
João Martins ◽  
Aitana Aires ◽  
Vinicius Casais ◽  
Joana Costa ◽  
Jorge Canhoto
Keyword(s):  
Endophytic Bacteria ◽  
Phytophthora Cinnamomi ◽  
Plant Protection ◽  
Agricultural Practices ◽  
Antagonistic Effect ◽  
Wild Plants ◽  
Growth Promoters ◽  
Arbutus Unedo ◽  
Strawberry Tree

Arbutus unedo L. is a resilient tree with a circum-Mediterranean distribution. Besides its ecological relevance, it is vital for local economies as a fruit tree. Several microorganisms are responsible for strawberry tree diseases leading to production constrictions. Thus, the development of alternative plant protection strategies is necessary and bacteria endophytes may increase their host overall fitness and productivity. As agricultural practices are a driving factor of microbiota, this paper aimed to isolate, identify and characterize endophytic bacteria from strawberry tree leaves from plants growing spontaneously in a natural environment as well as from plants growing on orchards. 62 endophytes were isolated from leaves and identified as Bacillus, Paenibacillus, Pseudomonas, Sphingomonas and Staphylococcus. Although a slightly higher number of species was found in wild plants, no differences in terms of diversity indexes were found. Sixteen isolates were tested in vitro for their antagonistic effect against A. unedo mycopathogens. B. cereus was the most effective antagonist causing a growth reduction of 20% in Glomerella cingulata and 40% in Phytophthora cinnamomi and Mycosphaerella aurantia. Also, several endophytic isolates exhibited plant growth-promoting potential. This study provides insights into the diversity of endophytic bacteria in A. unedo leaves and their potential role as growth-promoters and pathogen antagonists.

scholarly journals Identification and Characterization of Arbutus unedo L. Endophytic Bacteria Isolated from Wild and Cultivated Trees for the Biological Control of Phytophthora cinnamomi

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1569
Author(s):  
João Martins ◽  
Aitana Ares ◽  
Vinicius Casais ◽  
Joana Costa ◽  
Jorge Canhoto
Keyword(s):  
Endophytic Bacteria ◽  
Phytophthora Cinnamomi ◽  
Plant Protection ◽  
Agricultural Practices ◽  
Antagonistic Effect ◽  
Wild Plants ◽  
Growth Promoters ◽  
Arbutus Unedo ◽  
Strawberry Tree

Arbutus unedo L. is a resilient tree with a circum-Mediterranean distribution. Besides its ecological relevance, it is vital for local economies as a fruit tree. Several microorganisms are responsible for strawberry tree diseases, leading to production constrictions. Thus, the development of alternative plant protection strategies is necessary, such as bacterial endophytes, which may increase their host’s overall fitness and productivity. As agricultural practices are a driving factor of microbiota, this paper aimed to isolate, identify and characterize endophytic bacteria from strawberry tree leaves from plants growing spontaneously in a natural environment as well as from plants growing in orchards. A total of 62 endophytes were isolated from leaves and identified as Bacillus, Paenibacillus, Pseudomonas, Sphingomonas and Staphylococcus. Although a slightly higher number of species was found in wild plants, no differences in terms of diversity indexes were found. Sixteen isolates were tested in vitro for their antagonistic effect against A. unedo mycopathogens. B. cereus was the most effective antagonist causing a growth reduction of 20% in Glomerella cingulata and 40% in Phytophthora cinnamomi and Mycosphaerella aurantia. Several endophytic isolates also exhibited plant growth-promoting potential. This study provides insights into the diversity of endophytic bacteria in A. unedo leaves and their potential role as growth promoters and pathogen antagonists.

Isolation and Identification of a Potent PTP1B Inhibitor, Ursolic Acid, from Carolina Jasmine (Gelsemium sempervirens (L.) J.St.-Hil.)

2020 ◽  
Vol 17 (12) ◽  
pp. 939-943
Author(s):  
Toshiro Noshita ◽  
Yusuke Kakizoe ◽  
Satoshi Tanabe ◽  
Hidekazu Ouchi ◽  
Akihiro Tai
Keyword(s):  
Ursolic Acid ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Active Agent ◽  
Protein Tyrosine Phosphatase 1B ◽  
Inhibiting Activity ◽  
Inhibition Activity ◽  
Isolation And Identification ◽  
Gelsemium Sempervirens

Extracts of Carolina jasmine (Gelsemium sempervirens (L.) J.St.-Hil.) petals were evaluated in vitro for inhibition activity against protein tyrosine phosphatase 1B (PTP1B). The principle active agent was also isolated from the extract and identified as ursolic acid (1). This is the first report of ursolic acid from G. sempervirens and of PTP1B-inhibiting activity in the genus Gelsemium.

Molecular Detection of Bacterial Pathogens Directly from the Nasal Swabs and Lung Tissue of Sheep and Goats

2019 ◽  
Vol 15 (02) ◽  
pp. 22-25
Author(s):  
Sunaina Thakur ◽  
Subhash Verma ◽  
Prasenjit Dhar ◽  
Mandeep Sharma
Keyword(s):  
Pasteurella Multocida ◽  
Direct Detection ◽  
Bacterial Species ◽  
Economic Losses ◽  
Isolation And Identification ◽  
Sheep And Goats ◽  
Histophilus Somni ◽  
Nasal Swabs ◽  
Mycoplasma Spp

Respiratory infections of sheep and goats cause heavy morbidity and mortality, leading to huge economic losses. Conventional methods of diagnosis that include isolation and identification of incriminating microbes are time-consuming and fraught with logistic challenges. Direct detection of incriminating microbes using molecular tools is gaining popularity in clinical, microbiological settings. In this study, a total of 50 samples (44 nasal swabs and 6 lung tissues) from sheep and goats were screened for the detection of different bacterial species by in vitro amplification of genus or species-specific genes. Histophilus somni was detected in 2% goat samples, Trueperella pyogenes in 20% goat nasal swabs, whereas 22% goat nasal swab samples were found positive for Mycoplasma spp. None of the samples from sheep was detected positive for H. somni, T. pyogenes, Mycoplasma spp. Similarly, all samples, irrespective, whether from sheep or goats, showed negative results for Pasteurella multocida, Mannheimia haemolytica, and Corynebacterium pseudotuberculosis.

scholarly journals Cellulase Activity as a Mechanism for Suppression of Phytophthora Root Rot in Mulches

2011 ◽  
Vol 101 (2) ◽  
pp. 223-230 ◽  
Author(s):  
Brantlee Spakes Richter ◽  
Kelly Ivors ◽  
Wei Shi ◽  
D. M. Benson
Keyword(s):  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Cellulase Activity ◽  
Enzyme Concentration ◽  
Disease Suppression ◽  
In Vitro Assays ◽  
Infested Soil ◽  
Phytophthora Root Rot ◽  
Standard Curve

Wood-based mulches are used in avocado production and are being tested on Fraser fir for reduction of Phytophthora root rot, caused by Phytophthora cinnamomi. Research with avocado has suggested a role of microbial cellulase enzymes in pathogen suppression through effects on the cellulosic cell walls of Phytophthora. This work was conducted to determine whether cellulase activity could account for disease suppression in mulch systems. A standard curve was developed to correlate cellulase activity in mulches with concentrations of a cellulase product. Based on this curve, cellulase activity in mulch samples was equivalent to a cellulase enzyme concentration of 25 U ml–1 or greater of product. Sustained exposure of P. cinnamomi to cellulase at 10 to 50 U ml–1 significantly reduced sporangia production, but biomass was only reduced with concentrations over 100 U ml–1. In a lupine bioassay, cellulase was applied to infested soil at 100 or 1,000 U ml–1 with three timings. Cellulase activity diminished by 47% between 1 and 15 days after application. Cellulase applied at 100 U ml–1 2 weeks before planting yielded activity of 20.08 μmol glucose equivalents per gram of soil water (GE g–1 aq) at planting, a level equivalent to mulch samples. Cellulase activity at planting ranged from 3.35 to 48.67 μmol GE g–1 aq, but no treatment significantly affected disease progress. Based on in vitro assays, cellulase activity in mulch was sufficient to impair sporangia production of P. cinnamomi, but not always sufficient to impact vegetative biomass.

scholarly journals The Potential of Rhizoctonia-Like Fungi for the Biological Protection of Cereals against Fungal Pathogens

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 349
Author(s):  
Dominik Bleša ◽  
Pavel Matušinský ◽  
Romana Sedmíková ◽  
Milan Baláž
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Fusarium Culmorum ◽  
Suppressive Effect ◽  
Plant Production ◽  
Shoot Biomass ◽  
Organic Substrates

The use of biological control is becoming a common practice in plant production. One overlooked group of organisms potentially suitable for biological control are Rhizoctonia-like (Rh-like) fungi. Some of them are capable of forming endophytic associations with a large group of higher plants as well as mycorrhizal symbioses. Various benefits of endophytic associations were proved, including amelioration of devastating effects of pathogens such as Fusarium culmorum. The advantage of Rh-like endophytes over strictly biotrophic mycorrhizal organisms is the possibility of their cultivation on organic substrates, which makes their use more suitable for production. We focused on abilities of five Rh-like fungi isolated from orchid mycorrhizas, endophytic fungi Serendipita indica, Microdochium bolleyi and pathogenic Ceratobasidium cereale to inhibit the growth of pathogenic F. culmorum or Pyrenophora teres in vitro. We also analysed their suppressive effect on wheat infection by F. culmorum in a growth chamber, as well as an effect on barley under field conditions. Some of the Rh-like fungi affected the growth of plant pathogens in vitro, then the interaction with plants was tested. Beneficial effect was especially noted in the pot experiments, where wheat plants were negatively influenced by F. culmorum. Inoculation with S. indica caused higher dry shoot biomass in comparison to plants treated with fungicide. Prospective for future work are the effects of these endophytes on plant signalling pathways, factors affecting the level of colonization and surviving of infectious particles.

scholarly journals Allelopathic Effects of Three Herb Species on Phytophthora cinnamomi, a Pathogen Causing Severe Oak Decline in Mediterranean Wood Pastures

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 285
Author(s):  
Manuela Rodríguez-Romero ◽  
Belén Godoy-Cancho ◽  
Isabel M. Calha ◽  
José António Passarinho ◽  
Ana Cristina Moreira
Keyword(s):  
Phytophthora Cinnamomi ◽  
Raphanus Raphanistrum ◽  
Inhibitory Capacity ◽  
Pathogen Suppression ◽  
Pathogen Populations ◽  
Defensive Chemical ◽  
Chemical Response ◽  
Herb Species

The ability of three herbaceous plants (Diplotaxis tenuifolia (L.) DC., Eruca vesicaria L. and Raphanus raphanistrum L.) from Iberian wood pastures to reduce Phytophthora cinnamomi Rands pathogen populations through allelopathic relationships is studied. The inhibitory capacity of their aqueous root extracts (AREs) on mycelial growth and production of P. cinnamomi reproductive structures is analysed in vitro. In addition, Quercus seedlings were grown in infested by P. cinnamomi-soils and with the presence or absence of allelopathic and susceptible herb species to the pathogen to assess the defensive chemical response of Quercus seedlings through their leaf phenolic compounds. Results show a strong inhibitory capacity of AREs on P. cinnamomi activity in vitro and a protective effect of these herb species on Quercus plants against P. cinnamomi in vivo. D. tenuifolia would be especially suited for biological control in the pathogen suppression.

scholarly journals Infection Potential of Pleospora allii and Evaluation of Methods for Reduction of the Overwintering Inoculum of Brown Spot of Pear

Plant Disease ◽  
2006 ◽  
Vol 90 (12) ◽  
pp. 1511-1516 ◽  
Author(s):  
Isidre Llorente ◽  
Albert Vilardell ◽  
Emilio Montesinos
Keyword(s):  
Biological Control ◽  
Brown Spot ◽  
Control Methods ◽  
Optimum Temperature ◽  
Chemical Methods ◽  
Stemphylium Vesicarium ◽  
Mechanical Methods ◽  
Pleospora Allii ◽  
Evaluation Of Methods

The capacity for germination and pathogenicity to pear leaves of ascospores of Pleospora allii, the teleomorph of Stemphylium vesicarium, causal agent of brown spot of pear, were studied in vitro. Most ascospores germinated within 1 h at temperatures between 15 and 20°C, and the optimum temperature for germination was 18.9°C. Infections developed on wounded and non-wounded detached pear leaves, but were more frequent on wounded leaves. The minimum infective dose was one ascospore per wound. Biological, chemical, and mechanical methods for decreasing overwintering inoculum of P. allii were evaluated. Ascospores were discharged from March to May, depending on the orchard and year. Leaf shredding or removal were the most effective methods of reducing overwintering inoculum. Biological control methods based on application of Thichodermasp. formulations were partially effective. Chemical methods based on copper and urea treatments were ineffective.

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