scholarly journals Réaction de deux espèces d’igname (Dioscorea spp.) traitées avec du vin de palme (Elaeis guineensis Jacq.), aux champignons responsables des pourritures d’igname

Afrika Focus ◽  
2009 ◽  
Vol 22 (2) ◽  
Author(s):  
Patrice Kouamé Assiri ◽  
Attaky Hortense Diallo ◽  
Andres Tschannen ◽  
Severin Ake
Keyword(s):  
Mycelial Growth ◽  
Elaeis Guineensis ◽  
Preventive Treatment ◽  
Palm Wine ◽  
Palm Trees ◽  
In Vivo Tests ◽  
Natural Fungicide ◽  
Elaeis Guineensis Jacq

The sensitivity of Dioscorea alata var. bètè-bètè and D. cayenensis-rotundata var. krenglè treated with palm wine obtained from oil palm trees (Elaeis guineensis Jacq.) to seven fungi isolated from yam rots was assessed. Yam tubers were collected from two markets in Abidjan and also from storage sites in Bringakro (at 180 km from Abidjan, Côte d’Ivoire). Pathogenecity tests showed that Penicilium oxalicum was the most pathogenic among all fungi isolated. Krenglè was more susceptible than bètè-bètè. In vitro, fermented palm wine totally inhibited mycelial growth of all fungi isolated with the exception of P. oxalicum and Aspergillus niger. Inhibition percentage of mycelial growth of all fungi was more important for krenglè than bètè-bètè. Regardless the yam species, in vivo tests showed that fermented palm wine was more effective than non fermented palm wines when used as a preventive treatment. Key words: natural fungicide, palm wine, integrated disease management 

scholarly journals Réaction de deux espèces d’igname (Dioscorea spp.) traitées avec du vin de palme (Elaeis guineensis jacq.), aux champignons responsables des pourritures d’igname

Afrika Focus ◽  
2009 ◽  
Vol 22 (2) ◽  
pp. 11-26
Author(s):  
Patrice Kouamé Assiri ◽  
Attaky Hortense Diallo ◽  
Andres Tschannen ◽  
Seuerin Ake
Keyword(s):  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Elaeis Guineensis ◽  
Penicillium Oxalicum ◽  
Dioscorea Alata ◽  
Cote D’Ivoire ◽  
Palmier À Huile ◽  
Elaeis Guineensis Jacq

La sensibilité de Dioscorea alata var. bètè-bètè et de D. cayenensis-rotundata var. krenglè traitées avec du vin de palme extrait du palmier à huile (Elaeis guineensis Jacq.) à sept champignons isolés de tubercules d’igname pourris en post-récolte a été évaluée. Ces tubercules d’igname ont été collectés sur deux marchés de la ville d’Abidjan et sur les claies de stockage à Bringakro (à 180 km d’Abidjan, Côte d’Ivoire). A travers les tests de pathogénécité, Penicillium oxalicum s’est révélé le plus pathogénique de tous les champignons isolés. Krenglè s’est montrée plus sensible aux champignons inoculés que bètè-bètè. In vitro, le vin de palme fermenté a inhibé totalement la croissance mycélienne de tous les champignons à l’exception de P. oxalicum et d’Aspergillus niger. Les pourcentages d’inhibition de la croissance mycélienne des différents champignons sont plus élevés sur krenglè que sur bètè-bètè. In vivo, quelque soit l’espèce d’igname testée, le vin de palme fermenté s’est montré plus efficace que le vin non fermenté lorsqu’il est utilisé à titre préventif.

scholarly journals Prospecção de Aureobasidium pullulans, Isolado do Bioma Caatinga, no Biocontrole de Colletotrichum truncatum em Sementes de Soja

2020 ◽  
Vol 24 (4) ◽  
pp. 365-369
Author(s):  
Wictor Hugo Amorim Nogueira Paranaguá Carvalho ◽  
Helane França Silva ◽  
Alice Maria Gonçalves Santos ◽  
Elaine Martins Costa
Keyword(s):  
Biological Control ◽  
Glycine Max ◽  
Aureobasidium Pullulans ◽  
Inhibitory Action ◽  
Preventive Treatment ◽  
Colletotrichum Truncatum ◽  
In Vivo Tests ◽  
Glycine Max L

O fungo Colletotrichum truncatum (Schwein.) Andrus & W.D. Moore é um importante fitopatógeno em várias culturas de interesse econômico, inclusive na soja (Glycine max (L.) Merril), causando a doença conhecida como antracnose. Apesar do controle químico ser o método de controle mais usado pelos produtores rurais, o controle biológico se apresenta como uma alternativa sustentável para o manejo desta doença. Esta pesquisa avaliou o potencial do fungo Aureobasidium pullulans (de Bary & Lowenthal) G. Arnaud, originário do bioma Caatinga, no controle de C. truncatum. Foi avaliado o efeito inibitório sobre o crescimento micelial do patógeno a partir de compostos voláteis (in vitro), além de testes in vivo. Foram analisadas as variáveis germinação, índice de velocidade de germinação (IVG), massa seca e sanidade das sementes. Nos ensaios in vitro, os compostos voláteis produzidos pelo antagonista não apresentaram ação inibitória expressiva a C. truncatum. Nos testes in vivo, foi observada a ação inibitória de A. pullulans a C. truncatum em sementes de soja, por meio dos tratamentos preventivo e curativo. O tratamento preventivo proporcionou maior efetividade em relação ao tratamento curativo, evidenciando média superior de IVG (41,84) e menor incidência do patógeno (16,00%).  Desse modo, verificam-se as perspectivas do uso de A. pullulans no biocontrole de C. truncatum, especialmente, quando se realiza o tratamento preventivo. Este é o primeiro relato de A. pullulans sobre C. truncatum.   Palavras-chave: Antagonismo Microbiano. Controle Biológico. Fungos. Fitopatógeno.   Abstract The fungus Colletotrichum truncatum (Schwein.) Andrus & W.D. Moore is an important phytopathogen in several crops of economic interest, including soybean (Glycine max (L.) Merril), causing a disease known as anthracnose. Although chemical control is the most used control method by farmers, biological control presents itself as a sustainable alternative for the management of this disease. This study evaluated the potential of Aureobasidium pullulans (de Bary & Lowenthal) G. Arnaud, originating from Caatinga biome vegetation, in the control of C. truncatum. The inhibitory effect on the mycelial growth of the pathogen was evaluated from volatile compounds produced by the antagonist (in vitro) in addition to the in vivo tests. The following variables were analyzed, germination, germination speed index (GSI), dry mass and seed health. In the in vitro assays the volatile compounds produced by the antagonist presented no significant inhibitory action against C. truncatum. In in vivo tests, an inhibitory action of A. pullulans and C. truncatum was observed in soybean seeds, through preventive and curative treatments. The preventive treatment provided greater effectiveness in relation to the curative treatment, showing higher average of GSI (41.84) and lower incidence of the pathogen (16.00%). Thus, the perspectives of the use of A. pullulans in the biocontrol of C. truncatum are verified, especially when the preventive treatment is carried out. This is the first report of A. pullulans on C. truncatum.   Keywords: Microbial Antagonism. Biological Control. Fungi. Phytopathogen.

An Attempt at Biological Control of Blossom Blight of Rose Caused by Botrytis cinerea Using some Local Trichoderma spp. Strains

2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Limiting Factor ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Khuzestan Province ◽  
Inhibitory Potential ◽  
Cut Rose

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.

scholarly journals Improving the Biocontrol Potential of Bacterial Antagonists with Salicylic Acid against Brown Rot Disease and Impact on Nectarine Fruits Quality

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 209
Author(s):  
Nadia Lyousfi ◽  
Rachid Lahlali ◽  
Chaimaa Letrib ◽  
Zineb Belabess ◽  
Rachida Ouaabou ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Disease Severity ◽  
Mycelial Growth ◽  
Brown Rot ◽  
Antagonistic Bacteria ◽  
Biological Treatments ◽  
Rot Disease ◽  
The Impact

The main objective of this study was to evaluate the ability of both antagonistic bacteria Bacillus amyloliquefaciens (SF14) and Alcaligenes faecalis (ACBC1) used in combination with salicylic acid (SA) to effectively control brown rot disease caused by Monilinia fructigena. Four concentrations of salicylic acid (0.5%, 2%, 3.5%, and 5%) were tested under in vitro and in vivo conditions. Furthermore, the impact of biological treatments on nectarine fruit parameters’ quality, in particular, weight loss, titratable acidity, and soluble solids content, was evaluated. Regardless of the bacterium, the results indicated that all combined treatments displayed a strong inhibitory effect on the mycelial growth of M. fructigena and disease severity. Interestingly, all SA concentrations significantly improved the biocontrol activity of each antagonist. The mycelial growth inhibition rate ranged from 9.79% to 88.02% with the highest reduction rate recorded for bacterial antagonists in combination with SA at both concentrations of 0.5% and 3.5%. The in vivo results confirmed the in vitro results with a disease severity varying from 0.00% to 51.91%. A significant biocontrol improvement was obtained with both antagonistic bacteria when used in combination with SA at concentrations of 0.5% and 2%. The lowest disease severity observed with ACBC1 compared with SF14 is likely due to a rapid adaptation and increase of antagonistic bacteria population in wounded sites. The impact of all biological treatments revealed moderate significant changes in the fruit quality parameters with weight loss for several treatments. These results suggest that the improved disease control of both antagonistic bacteria was more likely directly linked to both the inhibitory effects of SA on pathogen growth and induced fruit resistance.

scholarly journals Polymorphisms in Plasmodium falciparum dihydropteroate synthetase and dihydrofolate reductase genes in Nigerian children with uncomplicated malaria using high-resolution melting technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adeyemi T. Kayode ◽  
Fehintola V. Ajogbasile ◽  
Kazeem Akano ◽  
Jessica N. Uwanibe ◽  
Paul E. Oluniyi ◽  
...  
Keyword(s):  
High Resolution ◽  
Dihydrofolate Reductase ◽  
Uncomplicated Malaria ◽  
High Resolution Melting ◽  
Intermittent Preventive Treatment ◽  
Preventive Treatment ◽  
Triple Mutant ◽  
Seasonal Malaria Chemoprevention

AbstractIn 2005, the Nigerian Federal Ministry of Health revised the treatment policy for uncomplicated malaria with the introduction of artemisinin-based combination therapies (ACTs). This policy change discouraged the use of Sulphadoxine-pyrimethamine (SP) as the second-line treatment of uncomplicated falciparum malaria. However, SP is used as an intermittent preventive treatment of malaria in pregnancy (IPTp) and seasonal malaria chemoprevention (SMC) in children aged 3–59 months. There have been increasing reports of SP resistance especially in the non-pregnant population in Nigeria, thus, the need to continually monitor the efficacy of SP as IPTp and SMC by estimating polymorphisms in dihydropteroate synthetase (dhps) and dihydrofolate reductase (dhfr) genes associated with SP resistance. The high resolution-melting (HRM) assay was used to investigate polymorphisms in codons 51, 59, 108 and 164 of the dhfr gene and codons 437, 540, 581 and 613 of the dhps gene. DNA was extracted from 271 dried bloodspot filter paper samples obtained from children (< 5 years old) with uncomplicated malaria. The dhfr triple mutant I51R59N108, dhps double mutant G437G581 and quadruple dhfr I51R59N108 + dhps G437 mutant haplotypes were observed in 80.8%, 13.7% and 52.8% parasites, respectively. Although the quintuple dhfr I51R59N108 + dhps G437E540 and sextuple dhfr I51R59N108 + dhps G437E540G581 mutant haplotypes linked with in-vivo and in-vitro SP resistance were not detected, constant surveillance of these haplotypes should be done in the country to detect any change in prevalence.

In Vitro Methods as a Tool in Neurotoxicity Studies

1995 ◽  
Vol 23 (4) ◽  
pp. 491-496
Author(s):  
Hanna Tähti ◽  
Leila Vaalavirta ◽  
Tarja Toimela
Keyword(s):  
Risk Evaluation ◽  
Toxicity Testing ◽  
In Vitro Models ◽  
In Vitro Tests ◽  
Industrial Chemicals ◽  
Mercury Compounds ◽  
Toxicological Data ◽  
In Vivo Tests

— There are several hundred industrial chemicals with neurotoxic potential. The neurotoxic risks of most of these chemicals are unknown. Additional methods are needed to assess the risks more effectively and to elucidate the mechanisms of neurotoxicity more accurately than is possible with the conventional methods. This paper deals with general tasks concerning the use of in vitro models in the evaluation of neurotoxic risks. It is based on our previous studies with various in vitro models and on recent literature. The induction of glial fibrillary acidic protein in astrocyte cultures after treatment with known neurotoxicants (mercury compounds and aluminium) is discussed in more detail as an important response which can be detected in vitro. When used appropriately with in vivo tests and with previous toxicological data, in vitro neurotoxicity testing considerably improves risk assessment. The incorporation of in vitro tests into the early stages of risk evaluation can reduce the number of animals used in routine toxicity testing, by identifying chemicals with high neurotoxic potential.

scholarly journals Role of in vitro and in vivo tests of hypersensitivity in beryllium workers.

1977 ◽  
Vol 30 (1) ◽  
pp. 24-28 ◽  
Author(s):  
C D Price ◽  
W J Williams ◽  
A Pugh ◽  
D H Joynson
Keyword(s):  
In Vivo Tests

scholarly journals Accelerated in vitro propagation of elite oil palm genotypes (Elaeis guineensis Jacq.) by substituting cytokinin with putrescine

2016 ◽  
Vol 15 (50) ◽  
pp. 2767-2775 ◽  
Author(s):  
Roseli Correa Thais ◽  
Yoshimitsu Motoike Sérgio ◽  
Paula de Souza Andrade Ana ◽  
Morra Coser Sara ◽  
Queiroz Vanessa ◽  
...  
Keyword(s):  
Oil Palm ◽  
In Vitro Propagation ◽  
Elaeis Guineensis ◽  
Elaeis Guineensis Jacq

scholarly journals Control of lettuce bottom rot by isolates of Trichoderma spp

2014 ◽  
Vol 40 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Zayame Vegette Pinto ◽  
Matheus Aparecido Pereira Cipriano ◽  
Amaury da Silva dos Santos ◽  
Ludwig Heinrich Pfenning ◽  
Flávia Rodrigues Alves Patrício
Keyword(s):  
Mycelial Growth ◽  
High Capacity ◽  
Dry Weight ◽  
Second Step ◽  
Trichoderma Spp ◽  
In Vivo Experiments ◽  
Bottom Rot ◽  
Trichoderma Isolates

Bottom rot, caused by Rhizoctonia solani AG 1-IB, is an important disease affecting lettuce in Brazil, where its biological control with Trichoderma was not developed yet. The present study was carried out with the aim of selecting Trichoderma isolates to be used in the control of lettuce bottom rot. Forty-six Trichoderma isolates, obtained with baits containing mycelia of the pathogen, were evaluated in experiments carried out in vitro and in vivo in a greenhouse in two steps. In the laboratory, the isolates were evaluated for their capabilities of parasitizing and producing toxic metabolic substances that could inhibit the pathogen mycelial growth. In the first step of the in vivo experiments, the number and the dry weight of lettuce seedlings of the cultivar White Boston were evaluated. In the second step, 12 isolates that were efficient in the first step and showed rapid growth and abundant sporulation in the laboratory were tested for their capability of controlling bottom rot in two repeated experiments, and had their species identified. The majority of the isolates of Trichoderma spp. (76%) showed high capacity for parasitism and 50% of them produced toxic metabolites capable of inhibiting 60-100% of R. solani AG1-IB mycelial growth. Twenty-four isolates increased the number and 23 isolates increased the dry weight of lettuce seedlings inoculated with the pathogen in the first step of the in vivo experiments.In both experiments of the second step, two isolates of T. virens, IBLF 04 and IBLF 50, reduced the severity of bottom rot and increased the number and the dry weight of lettuce seedlings inoculated with R. solani AG1-IB. These isolates had shown a high capacity for parasitism and production of toxic metabolic substances, indicating that the in vitro and in vivo steps employed in the present study were efficient in selecting antagonists to be used for the control of lettuce bottom rot.

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