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Biocontrol de la pudrición de raíz de nochebuena de interior con Trichoderma spp.
Osuna-Canizalez, Felipe de Jesús;Moreno-López, María Félix;García-Pérez, Faustino;Ramírez-Rojas, Sergio;Canul-Ku, Jaime;
Revista mexicana de ciencias agrícolas , 2012,
Abstract: in morelos, root rot caused by fusarium spp., is one of the main diseases of indoor poinsettia. in order to prevent or control its devastating effect, frequent applications of chemical products are performed, with inherent risks to human health and environment. in quest for alternative biorational options, an essay in which three commercial strains of trichoderma spp., was done, in three different substrates: s1= "organic soil" (70% v/v)+thick tezontle (15% v/v)+thin tezontle (10% v/v)+agrolita (5% v/v); s2= peat moss (80% v/v)+ coconut fiber (20% v/v); s3= "organic soil" (70%)+"tepojal" (30%), in most common commercial varieties, freedom red and prestige red. a factorial design of 4 x 3 x 2 treatment was used and resulting treatments were evaluated in a completely random design with six repetitions. regards root rot incidence, commercial strains of trichoderma spp., did not show differences between them, either with chemical control. root rot was associated with s2, due low aeration capacity, and only it was seen in prestige red. population of trichoderma spp.,(ufc g-1) in the substrate at end of cycle was the same (p< 0.05) between commercial strains and between them and the control (without inoculation), due presence of native strains of trichoderma in organic components of substrates ("organic soil", peat moss and coconut fiber).
Aspects of the effects of the fungus Trichoderma spp. in biocontrol of pathogens of agricultural crops
Larissa Romao Saito,Lívia Luiza Souza Rezende Sales,Lais Martinckoski,Rafael Royer
Pesquisa Aplicada & Agrotecnologia , 2010, DOI: 10.5777/1515
Abstract: Biological control is considered a natural tool and an ecological alternative to overcome the problems caused by chemical methods for the protection of plants. From the fungi with potential of antagonism, the genus Trichoderma is one of the most researched and studied. This fungus is a microorganism naturally found in soil, which presents an important ecological function, and participates of several processes in this mean. The objective of the work is to develop a discussion about aspects of the biological control, specially in relation to effects of the fungus Trichoderma spp. in the biocontrol of pathogens of agricultural crops. With the discussions along the texts, it is considered that the biological control is a system which is being target of frequent and continuous investigation being an important tool for the control of several problems of phytossanity which occur in agriculture. Among the agents which are noteworthy in the investigations is the fungus Trichoderma spp., in which it was verified action as biocontrol agent and in some cases as growth promoter. Controle biológico é considerado uma ferramenta natural e uma alternativa ecológica para superar os problemas causados por métodos químicos para a prote o de plantas. Dos fungos com potencial de antagonismo, o gênero Trichoderma é um dos mais pesquisados e estudados. Este fungo é um microrganismo naturalmente encontrado no solo, que apresenta uma importante fun o ecológica participando de diversos processos neste meio. O objetivo do trabalho é desenvolver uma discuss o sobre aspectos do controle biológico, especialmente com rela o efeitos do fungo Trichoderma spp. no biocontrole de patógenos de culturas agrícolas. Com as discuss es ao longo do texto considera-se que o controle biológico é um sistema que está sendo alvo de frequentes e contínuas investiga es se constituindo em uma alternativa importante para o controle de diferentes problemas de fitoassanidade que ocorrem na agricultura. Dentre os agentes que vem merecendo grande destaque nas investiga es está o fungo Trichoderma spp, para o qual foram verificadas atua es como agente de biocontrole e em alguns casos como promotores de crescimento.
Potato Vascular Fusarium wilt in Tunisia: Incidence and Biocontrol by Trichoderma spp.  [PDF]
Fakher Ayed,Mejda Daami-Remadi,Hayfa Jabnoun-Khiareddine,Mohamed El Mahjoub
Plant Pathology Journal , 2006,
Abstract: Pathogen isolations from potato tubers showing dry rot symptoms revealed the presence of Fusarium oxysporum f. sp. tuberosi in different Tunisian regions. Pathogenicity tests of different isolates were realized on potato plants. Typical symptoms of vascular wilt disease were observed and noted. After wilting, inoculated plants were totally damaged. Trichoderma spp. were evaluated for their antagonistic potential against F. oxysporum f. sp. tuberosi in vitro and in vivo. Trichoderma harzianum, T. viride and T. virens inhibited the mycelial growth of F. oxysporum f. sp. tuberosi. The antagonism included lysis and dissolution of the host cytoplasm and/or transformation into cords and/or coiling around pathogen hyphae. Moreover, substrate application of Trichoderma species (108 spores per mL) before inoculation by F. oxysporum f. sp. tuberosi controlled Fusarium wilt of potato plants compared with non-inoculated plants and untreated-inoculated plants. This approach may be beneficial for biological control in F. oxysporum f. sp. tuberosi and could allow protecting plants from this pathogen.
Biocontrol potential of Trichoderma spp. against important soilborne diseases of vegetable crops  [cached]
Indian Phytopathology , 2011,
Abstract: In vitro studies on the efficacy of Trichoderma spp. against soilborne pathogens revealed maximum inhibition of mycelial growth by T. harzianum against Rhizoctonia solani, Pythium debaryanum, Sclerotinia minor and Fusarium oxysporum f. sp. pisi. Bioagent, T. viride showed maximum inhibition of mycelial growth of S. rolfsii. Similarly, the culture filtrate of T. harzianum showed maximum inhibition of mycelial growth of R. solani, Pythium debaryanum, S. minor, F. oxysporum f.sp. pisi and S. rolfsii. T. harzianum inhibited significantly the conidial germination of F. oxysporum f.sp. pisi and sclerotial germination of S. rolfsii as compared to other bioagents. Wheat bran alone or in combination with FYM in the ratio of 1:1 and 1:2 respectively supported maximum multiplication of T. harzianum followed by shelled maize cob powder, maize flour and FYM. Wheat bran based formulation as soil application @ 2 g/kg soil was found the best delivery system followed by seed treatment with same formulation @ 2g /kg seed or talc based formulation as seed treatment @ 2g/kg seed in controlling the root rot of pea and collar rot of tomato in pot experiments.
Variability in biocontrol potential and microbial interaction of Trichoderma spp. with soil inhabiting antagonistic bacteria Pseudomonas fluorescens
Indian Phytopathology , 2011,
Abstract: Ten isolates of Trichoderma spp. collected from diverse agro-ecological habitats of West Bengal were evaluated against Fusarium oxysporum f.sp. radicislycopersici through dual culture technique and production of volatile and nonvolatile substances. T1, T7 and T10 isolates were most efficient against the test pathogen in dual culture. Similarly, T7 isolate of T. virens was highly effective against the pathogens causing 62.5% mycelia inhibition over the control by the production of volatile metabolites, where as T10 retarded 64.4% mycelia growth followed T1, T6, T2, T4 and T7 respectively which were statistically at par in their antagonistic effect by production of non volatile substances at 10% concentration. When the interaction between Trichoderma isolates and P. fluorescens on KMB was tested, the growth inhibition of biocontrol fungi was noticed upto 59.1% over control. T1 isolate of T. viride showed high level of tolerance against the Pseudomonas inhibited only 11.9% followed by T6 (13.5%) and T3 (22.4%), T5 isolate of Trichoderma was highly inhibitory against the bacterial antagonist. Inhibitory effect of P. fluorescens was comparatively more when the bacterial strain inoculated 24 h before the Trichoderma was seeded. Again significant reduction in growth of antagonistic fungus was also observed with the culture filtrate of the antagonistic bacterium even at 5% concentration. In the present investigation T6 showed highly tolerance inhibiting only 5.55% growth followed by T1 (7.03%). However in steamed soil recoverable numbers of Trichoderma population increased over the 14 days time period in all the treatments.
Ophiopgon Japonicus Root Rot Disease and Trichoderma spp. Based Biocontrol

Zeng Hualan,Ye Pengsheng,He Lion,Li Qiongfang,Wei Shugu,Ye Xiangping,He Zunxing,

世界科学技术-中医药现代化 , 2006,
Abstract: Root rot disease of Ophiopgon japonicus, a soil-borne disaster that causes losses to both yield and quality of the produce, is a result of Fusarium oxysporum attack. Biocontrol techniques promise a treating effect that chemical pesticides have never produced. In this study, 24 strains of Trichoderma spp. were isolated using the dilution-plating method, from 26 rhizospheric soil samples of the herbal plants. Trichoderma harzianum T23 and T158, screened out from the samples, are enjoying apparent inhibiting effects on the pathogens, with a validity of 84.07% and 83.47% respectively. Competing for nutrition and space, as well as the mycoparasitism, are the main approaches through which Fusarium oxysporum is contained. Field tests show that T23 is effective in controlling the root rot disease of Ophiopgon japonicus. T23, at a dosage of 500g/666.7m2 , works well for an effect of 67.52%, which is significantly higher than the mancozeb at a dosage of 300g/666.7m2. The biocontrol technique also promotes the development of Ophiopgon japonicus plant. The yield of the Ophiopgon japonicus treated with T23 is 24.46% higher than the control group.
Biological Control with Trichoderma Spp. With Emphasis on T. harzianum  [PDF]
Nusret Ozbay,Steven E. Newman
Pakistan Journal of Biological Sciences , 2004,
Abstract: Biocontrol with antagonistic microbes such as the fungus Trichoderma is one area of research. Trichoderma spp. are among the most common saprophytic fungi. Trichoderma spp. are well documented as effective biological control agents of plant diseases caused by both soilborne fungi and leaf- and fruit-infecting plant pathogenic fungi. Trichoderma spp. are often very fast growing and rapidly colonize substrates, thus excluding pathogens such as Fusarium spp. Several of these fungi are also parasitic to other fungi including plant pathogens. Trichoderma harzianum Rifai is an efficient biocontrol agent that is commercially produced to prevent development of several soil pathogenic fungi. T. harzianum alone or in combination with other Trichoderma species can be used in biological control of several plant diseases. An additional advantage for T. harzianum is that it increases growth in various plants. This review discussed biological control with Trichoderma spp. with emphasis on T. harzianum Biological Control with Trichoderma spp. with emphasis on T. harzianum and numerous mechanisms that Trichoderma spp. have evolved in attacking other fungi and enhancing plant and root growth
Trichoderma Biocontrol: Signal Transduction Pathways Involved in Host Sensing and Mycoparasitism
Susanne Zeilinger,Markus Omann
Gene Regulation and Systems Biology , 2007,
Abstract: Fungi of the genus Trichoderma are used as biocontrol agents against several plant pathogenic fungi like Rhizoctonia spp., Pythium spp., Botrytis cinerea and Fusarium spp. which cause both soil-borne and leaf- or flower-borne diseases of agricultural plants. Plant disease control by Trichoderma is based on complex interactions between Trichoderma, the plant pathogen and the plant. Until now, two main components of biocontrol have been identified: direct activity of Trichoderma against the plant pathogen by mycoparasitism and induced systemic resistance in plants. As the mycoparasitic interaction is host-specific and not merely a contact response, it is likely that signals from the host fungus are recognised by Trichoderma and provoke transcription of mycoparasitism-related genes.In the last few years examination of signalling pathways underlying Trichoderma biocontrol started and it was shown that heterotrimeric G-proteins and mitogen-activated protein (MAP) kinases affected biocontrol-relevant processes such as the production of hydrolytic enzymes and antifungal metabolites and the formation of infection structures. MAPK signalling was also found to be involved in induction of plant systemic resistance in Trichoderma virens and in the hyperosmotic stress response in Trichoderma harzianum. Analyses of the function of components of the cAMP pathway during Trichoderma biocontrol revealed that mycoparasitism-associated coiling and chitinase production as well as secondary metabolism are affected by the internal cAMP level; in addition, a cross talk between regulation of light responses and the cAMP signalling pathway was found in Trichoderma atroviride.
Biocontrol mechanisms of Trichoderma strains
Benítez,Tahía; Rincón,Ana M.; Limón,M. Carmen; Codón,Antonio C.;
International Microbiology , 2004,
Abstract: the genus trichoderma comprises a great number of fungal strains that act as biological control agents, the antagonistic properties of which are based on the activation of multiple mechanisms. trichoderma strains exert biocontrol against fungal phytopathogens either indirectly, by competing for nutrients and space, modifying the environmental conditions, or promoting plant growth and plant defensive mechanisms and antibiosis, or directly, by mechanisms such as mycoparasitism. these indirect and direct mechanisms may act coordinately and their importance in the biocontrol process depends on the trichoderma strain, the antagonized fungus, the crop plant, and the environmental conditions, including nutrient availability, ph, temperature, and iron concentration. activation of each mechanism implies the production of specific compounds and metabolites, such as plant growth factors, hydrolytic enzymes, siderophores, antibiotics, and carbon and nitrogen permeases. these metabolites can be either overproduced or combined with appropriate biocontrol strains in order to obtain new formulations for use in more efficient control of plant diseases and postharvest applications.
Evaluation of Trichoderma spp. and Clonostachys spp. Strains to Control Fusarium circinatum in Pinus radiata Seedlings Evaluación de Cepas de Trichoderma spp. y Clonostachys spp. para Controlar Fusarium circinatum en Plántulas de Pinus radiata  [cached]
Priscila Moraga-Suazo,Alex Opazo,Salomé Zaldúa,Gastón González
Chilean Journal of Agricultural Research , 2011,
Abstract: The fungus Fusarium circinatum Nirenberg & O’Donnell causes pine pitch canker, an important disease for conifers worldwide. F. circinatum was first detected in Chile in 2001 and to date is present in nurseries and clonal hedges from Libertador General Bernardo O’Higgins Region to Los Rios Region. The purpose of this study was to evaluate the potential of Trichoderma spp. and Clonostachys spp. strains to control F. circinatum in Pinus radiata D. Don seedlings in the absence of other effective control methods. Eighty-one Trichoderma spp. and Clonostachys spp. strains were evaluated through in vitro assays to determine their ability to act as antagonists of F. circinatum and 21 strains were tested for their ability to reduce post-emergence mortality and increase P. radiata survival under greenhouse conditions. During in vitro experiments, 15 strains of Trichoderma inhibited mycelial growth of the pathogen by more than 60% and one strain of Clonostachys showed parasitism of F. circinatum hyphae. Greenhouse experiments showed no control of the disease when the antagonists were added to substrate after the pathogen. However, when the antagonists were added before the pathogen, four strains (Clonostachys UDC-32 and UDC-222 and Trichoderma UDC-23 and UDC-408) reduced post-emergence mortality between 80 and 100%. Among these strains, only Clonostachys UDC-222 significantly increased the survival of P. radiata seedlings. These results showed that Clonostachys UDC-222 has the potential to be used as a biocontrol agent against F. circinatum in the production of P. radiata plants. Fusarium circinatum Nirenberg & O’Donnell es el hongo que causa el cancro resinoso del pino, una enfermedad de importancia mundial en coníferas. En Chile, F. cicirnatum fue detectado por primera vez el a o 2001 y a la fecha se encuentra presente en algunos viveros y huertos clonales desde la Región del Libertador General Bernardo O’Higgins hasta la Región de Los Ríos. Debido a la ausencia de métodos eficientes para controlar este patógeno, el propósito de este estudio fue evaluar el potencial uso de cepas de Trichoderma y Clonostachys como control de F. circinatum en plántulas de Pinus radiata D. Don. Ochenta y un cepas de Trichoderma spp. y Clonostachys spp. fueron evaluadas a través de ensayos in vitro para determinar su habilidad para actuar como antagonistas de F. circinatum y 21 cepas fueron probadas por su habilidad para reducir la mortalidad post-emergencia e incrementar la supervivencia de P. radiata bajo condiciones de invernadero. Durante los experimentos in vitro, 15 cepas de Tr
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