Differential effect of chitosan on root rot fungal pathogens in forest nurseries

2000 ◽  
Vol 77 (10) ◽  
pp. 1460-1468 ◽  
Author(s):  
Philippe Laflamme ◽  
Nicole Benhamou ◽  
Guy Bussières ◽  
Michel Dessureault
Keyword(s):  
Root Rot ◽  
Fungal Pathogens ◽  
Wall Thickening ◽  
Growth Morphology ◽  
Morphological Alterations ◽  
Fusarium Acuminatum ◽  
Transmission Electron ◽  
Forest Nurseries ◽  
Membrane Cell

The effect of chitosan on the growth, morphology, and ultrastructure of Cylindrocladium floridanum Sobers & Seymour, Cylindrocarpon destructans (Zinss.) Scholten, Fusarium acuminatum Ellis & Everh., and Fusarium oxysporum Schlecht. was investigated in vitro. Chitosan was found to reduce the radial growth of all the fungi studied with some differences. Light microscope observations showed that chitosan induced morphological alterations to all fungi. Transmission electron microscope investigations revealed ultrastructural alterations such as increased vacuolation, retraction, and alteration of the plasma membrane, cell wall thickening, hyphal distortion, and cytoplasm aggregation. The possible modes of action of chitosan are discussed.

scholarly journals Biological control of strawberry crown rot, root rot and grey mould by the beneficial fungus Aureobasidium pullulans

BioControl ◽  
2021 ◽  
Author(s):  
Mudassir Iqbal ◽  
Maha Jamshaid ◽  
Muhammad Awais Zahid ◽  
Erik Andreasson ◽  
Ramesh R. Vetukuri ◽  
...  
Keyword(s):  
Root Rot ◽  
Fungal Pathogens ◽  
Aureobasidium Pullulans ◽  
Grey Mould ◽  
Lesion Size ◽  
Plant Diseases ◽  
Crown Rot ◽  
Whole Plants

AbstractUtilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33–48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.

scholarly journals Control of Wheat Fusarium Head Blight by Heat-Stable Antifungal Factor (HSAF) from Lysobacter enzymogenes

Plant Disease ◽  
2019 ◽  
Vol 103 (6) ◽  
pp. 1286-1292 ◽  
Author(s):  
Yangyang Zhao ◽  
Chao Cheng ◽  
Tianping Jiang ◽  
Huiyong Xu ◽  
Yun Chen ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Fungal Pathogens ◽  
Ultrastructural Changes ◽  
Wall Thickening ◽  
Head Blight ◽  
Lysobacter Enzymogenes ◽  
Heat Stable ◽  
Wide Range

Heat-stable antifungal factor (HSAF), which belongs to the polycyclic tetramate macrolactam family, was isolated from Lysobacter enzymogenes fermentations and exhibited inhibitory activities against a wide range of fungal pathogens. In this study, the antifungal activity of HSAF against Fusarium graminearum in vitro and in vivo was investigated. A total of 50% of mycelial growth of F. graminearum was suppressed with 4.1 μg/ml of HSAF (EC50 value). HSAF treatment resulted in abnormal morphology of the hyphae, such as curling, apical swelling, and depolarized growth. Furthermore, HSAF adequately inhibited conidial germination and conidiation of F. graminearum with an inhibition rate of 100% when 1 and 6 μg/ml of HSAF were applied, respectively. HSAF caused ultrastructural changes of F. graminearum, including cell wall thickening and plasmolysis. Moreover, the application of HSAF significantly controlled Fusarium head blight in wheat caused by F. graminearum in the field. Overall, these results indicate that HSAF has potential for development as a fungicide against F. graminearum.

scholarly journals Biological Control of Pathogens Causing Root Rot Complex in Field Pea Using Clonostachys rosea Strain ACM941

2003 ◽  
Vol 93 (3) ◽  
pp. 329-335 ◽  
Author(s):  
Allen G. Xue
Keyword(s):  
Root Rot ◽  
Seed Treatment ◽  
Fungal Pathogens ◽  
Seedling Emergence ◽  
Field Pea ◽  
Mycosphaerella Pinodes ◽  
Limiting Factor ◽  
Aphanomyces Euteiches ◽  
Clonostachys Rosea

Pea root rot complex (PRRC), caused by Alternaria alternata, Aphanomyces euteiches, Fusarium oxysporum f. sp. pisi, F. solani f. sp. pisi, Mycosphaerella pinodes, Pythium spp., Rhizoctonia solani, and Sclerotinia sclerotiorum, is a major yield-limiting factor for field pea production in Canada. A strain of Clonostachys rosea (syn. Gliocladium roseum), ACM941 (ATCC 74447), was identified as a mycoparasite against these pathogens. When grown near the pathogen, ACM941 often was stimulated to produce lateral branches that grew directly toward the pathogen mycelium, typically entwining around the pathogen mycelium. When applied to the seed, ACM941 propagated in the rhizosphere and colonized the seed coat, hypocotyl, and roots as the plant developed and grew. ACM941 significantly reduced the recovery of all fungal pathogens from infected seed, increased in vitro seed germination by 44% and seedling emergence by 22%, and reduced root rot severity by 76%. The effects were similar to those of thiram fungicide, which increased germination and emergence by 33 and 29%, respectively, and reduced root rot severity by 65%. When soil was inoculated with selected PRRC pathogens in a controlled environment, seed treatment with ACM941 significantly increased emergence by 26, 38, 28, 13, and 21% for F. oxysporum f. sp. pisi, F. solani f. sp. pisi, M. pinodes, R. solani, and S. sclerotiorum, respectively. Under field conditions from 1995 to 1997, ACM941 increased emergence by 17, 23, 22, 13, and 18% and yield by 15, 6, 28, 6, and 19% for the five respective pathogens. The seed treatment effects of ACM941 on these PRRC pathogens were greater or statistically equivalent to those achieved with thiram. Results of this study suggest that ACM941 is an effective bioagent in controlling PRRC and is an alternative to existing chemical products.

scholarly journals Biological control of strawberry crown rot, root rot and grey mould by the beneficial fungus Aureobasidium pullulans

2021 ◽  
Author(s):  
Mudassir Iqbal ◽  
Maha Jamshaid ◽  
Muhammad Awais Zahid ◽  
Erik Andreasson ◽  
Ramesh R. Vetukuri ◽  
...  
Keyword(s):  
Root Rot ◽  
Fungal Pathogens ◽  
Aureobasidium Pullulans ◽  
Grey Mould ◽  
Lesion Size ◽  
Plant Diseases ◽  
Crown Rot ◽  
Whole Plants

Abstract Utilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control, crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33- 48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea . In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.

scholarly journals COMPARATIVE ASSESSMENT OF FUNGICIDAL ACTIVITY OF PREPARATIONS FOR PRESOWING TREATMENT OF WINTER WHEAT

2021 ◽  
Vol 4 (28) ◽  
pp. 149-158
Author(s):  
N.M. Sidorov ◽  
◽  
E.A. Gyrnets ◽  
M.M. Astakhov ◽  
K.Yu. Saenko ◽  
...  
Keyword(s):  
Root Rot ◽  
Seed Treatment ◽  
Fungal Pathogens ◽  
Fungicidal Activity ◽  
Plant Protection ◽  
Aerial Mycelium ◽  
Plant Protection Products ◽  
Inhibitory Effect ◽  
Wide Range

The massive use of one-component fungicides has caused the problem of the emergence of resistant forms of phytopathogens. The development of multicomponent plant protection products is one of the ways of dealing with such a situation. The aim of the study is to determine the effectiveness of multicomponent chemical dressing agents in suppressing the most common fungal pathogens and seed infections in vitro. This work was performed in 2020 in the Federal Research Center for Biological Plant Protection (Krasnodar) in the laboratory of the creation of microbiological plant protection products and a collection of microorganisms. Fungi of the Fusarium, Microdochium, Bipolaris, Alternaria, Penicillium, Rhizoctonia, Septoria, Pyrenophora genera were used as test objects. The fungicidal activity of chemical preparations against economically significant phytopathogens causing root rot was evaluated in laboratory conditions by the method of serial dilutions followed by sowing on a nutrient medium. In addition, the effectiveness of the preparations was investigated by the method of treated seeds phytoexamination according to GOST 12044–93. The preparations, which included triazoles and phenylpyrroles, had the strongest inhibitory effect (100 %) on pathogens of Rhizoctonia, helminthosporiosis and septoria. The preparation containing compounds of the group of triazoles and strobilurins suppressed the growth of Rhizoctonia solani only. The preparations’ inhibitory effect on a number of phytopathogenic fungi was manifested in growth retardation, absence of aerial mycelium development and mycelium pigmentation. Concerning the causative agents of Fusarium root rot, the two-component preparations efficacy ranged from 51 % to 74.4 %; three-component one – from 42.9 % to 84.7 % depending on the species of the genus Fusarium. Presowing seed treatment made it possible to inhibit the growth of fungi of the genera Fusarium, Mucor, Aspergillus; significantly inhibit the development of the fungus Alternaria (spread in the experimental variant – 1.7 %, in the control variant – 46.7 %). From the data obtained, it can be concluded that multicomponent preparations based on triazoles and phenylpyrroles are highly effective in suppressing a wide range of phytopathogens and can be recommended for presowing seed treatment.

Differential effect of chitosan on root rot fungal pathogens in forest nurseries

1999 ◽  
Vol 77 (10) ◽  
pp. 1460-1468 ◽  
Author(s):  
Philippe Laflamme ◽  
Nicole Benhamou ◽  
Guy Bussières ◽  
Michel Dessureault
Keyword(s):  
Root Rot ◽  
Differential Effect ◽  
Fungal Pathogens ◽  
Forest Nurseries

Developmental changes in cardiac recovery from anoxia-reoxygenation

2002 ◽  
Vol 283 (2) ◽  
pp. R379-R388 ◽  
Author(s):  
David Sedmera ◽  
Pavel Kucera ◽  
Eric Raddatz
Keyword(s):  
Adult Animal ◽  
Developmental Stages ◽  
Complete Atrioventricular Block ◽  
Morphological Alterations ◽  
Baseline Activity ◽  
Transmission Electron ◽  
Hypoxic Environment ◽  
Developmental Variations ◽  
Complete Atrioventricular

The developing cardiovascular system is known to operate normally in a hypoxic environment. However, the functional and ultrastructural recovery of embryonic/fetal hearts subjected to anoxia lasting as long as hypoxia/ischemia performed in adult animal models remains to be investigated. Isolated spontaneously beating hearts from Hamburger-Hamilton developmental stages 14( 14HH), 20HH, 24HH, and 27HH chick embryos were subjected in vitro to 30 or 60 min of anoxia followed by 60 min of reoxygenation. Morphological alterations and apoptosis were assessed histologically and by transmission electron microscopy. Anoxia provoked an initial tachycardia followed by bradycardia leading to complete cardiac arrest, except for in the youngest heart, which kept beating. Complete atrioventricular block appeared after 9.4 ± 1.1, 1.7 ± 0.2, and 1.6 ± 0.3 min at stages 20HH, 24HH, and 27HH, respectively. At reoxygenation, sinoatrial activity resumed first in the form of irregular bursts, and one-to-one atrioventricular conduction resumed after 8, 17, and 35 min at stages 20HH, 24HH, and 27HH, respectively. Ventricular shortening recovered within 30 min except at stage 27HH. After 60 min of anoxia, stage 27HHhearts did not retrieve their baseline activity. Whatever the stage and anoxia duration, nuclear and mitochondrial swelling observed at the end of anoxia were reversible with no apoptosis. Thus the embryonic heart is able to fully recover from anoxia/reoxygenation although its anoxic tolerance declines with age. Changes in cellular homeostatic mechanisms rather than in energy metabolism may account for these developmental variations.

Protection of black spruce seedlings against Cylindrocladium root rot with ectomycorrhizal fungi

1999 ◽  
Vol 77 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Chantal Morin ◽  
Julie Samson ◽  
Michel Dessureault
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Picea Mariana ◽  
Root Rot ◽  
Black Spruce ◽  
Inhibitory Effect ◽  
Paxillus Involutus ◽  
Hebeloma Cylindrosporum ◽  
Cylindrocladium Floridanum ◽  
Forest Nurseries

Cylindrocladium floridanum Sobers and Seymour, principal causal agent of root rot of conifers in forest nurseries, was grown in vitro with four species of ectomycorrhizal fungi, Paxillus involutus, Hebeloma cylindrosporum, Laccaria bicolor, and Tricholoma sp. The effect of inoculating black spruce seedlings (Picea mariana (Mill.) B.S.P.) with P. involutus was also investigated. Tricholoma sp. and especially P. involutus and H. cylindrosporum inhibited growth of C. floridanum in Petri dishes, while L. bicolor was inhibited and completely covered by C. floridanum. Hyphae of the pathogen in the contact zone were deteriorated in the presence of P. involutus and H. cylindrosporum. The inoculation of P. involutus reduced the number of infected black spruce seedlings by approximately 50%. However, the simultaneous inoculation of two different strains of P. involutus did not significantly reduce disease development. Linear regression demonstrated that the percentage of infected plants was negatively correlated with mycorrhiza formation. The relation between these two variables also showed that even if colonization by P. involutus is poor or null, it has some inhibitory effect against Cylindrocladium root rot.Key words: Paxillus involutus, Cylindrocladium floridanum, root rot, ectomycorrhizal fungi, biological control, Picea mariana.

scholarly journals Unveiling of Dominant Fungal Pathogens Associated With Rusty Root Rot of Panax notoginseng Based on Multiple Methods

Plant Disease ◽  
2017 ◽  
Vol 101 (12) ◽  
pp. 2046-2052 ◽  
Author(s):  
Chunyi Mi ◽  
Ruihuan Yang ◽  
Junfeng Rao ◽  
Shaozhou Yang ◽  
Fugang Wei ◽  
...  
Keyword(s):  
Root Rot ◽  
Fungal Pathogens ◽  
Panax Notoginseng ◽  
Real Time Quantitative Pcr ◽  
Average Abundance ◽  
Sustainable Cultivation ◽  
His3 Gene ◽  
Important Disease

Root rot is an important disease hampering the sustainable cultivation of Panax notoginseng. Culture-dependent and independent techniques were used to elucidate the dominant fungal pathogen of rusty root rot of P. notoginseng. Based on Illumina sequencing profiles for fungi using ITS primers, five phyla—namely Ascomycota, Basidiomycota, Glomeromycota, Zygomycota, and Chytridiomycota—were identified, and the analyses showed that the Ascomycota was the dominant phylum (∼50 to 97%), especially in the symptomatic samples. Out of 226 total genera identified, seven genera had over 1% average abundance, including Ilyonectria, Fusarium, Tetracladium, Cladosporium, Rhizophagus, Alternaria, and Perisporiopsis. However, only Ilyonectria was the predominant genera in the symptomatic samples (∼76 to 80%), while the others, including Fusarium, had higher abundances in asymptomatic samples. Based on in vitro and in vivo pathogenicity, the isolate G3B was demonstrated to be the pathogen causing rusty root rot of P. notoginseng, and it was identified as Ilyonectria mors-panacis. Based on primers F2-R2 targeting the His3 gene of Ilyonectria, real-time quantitative PCR (qPCR) was performed as an additional proof confirming that I. mors-panacis was the dominant pathogen in the symptomatic samples during the years of the study (2014-2015).

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