2024-03-19T10:36:37Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1600982018-11-03T01:56:03Zcom_10261_74com_10261_6col_10261_453
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Rincón Romero, Ana María
author
Chaki, Mounira
author
Dueñas Sánchez, Rafael
author
Valverde-Corredor, Antonio
author
Ruano Rosa, David
author
Begara Morales, Juan Carlos
author
Prieto, Pilar
author
Luque, Francisco
author
Bautista Barroso, Juan
author
Mercado-Blanco, Jesús
author
2014-03
Verticillium wilt of olive tree (Olea europaea L.) (VWO), caused by the soil-borne fungus Verticillium dahliae Kleb., is
considered one of the most devastating diseases affecting this crop in many are as, particularly in the Mediterranean
Basin. It can only be effectively confronted by implementing an integrated disease management strategy. Preventive
measures such as the treatment of the root systems of pathogen-free certified propagationjplanting material at
the nursery stage with microbial antagonists emerges as a promising alternative. Species of the soil-borne fungus
Trichoderma have been widely described as biocontrol agents (BCAs) of severa! phytopathogenic fungi by means of
different mechanisms, including the ability to colonize root tissues endophytically and to elicit systemic resistance in
plants. In this studywe aimed to evaluate the potential ofT. harzianum CECT 2413 as effective BCA ofVWO. Strain CECT 2413 has shown to be able to in vitro overgrow different representatives of V. dahliae pathotypes infecting olive: i.e., highly-virulent, defoliating (D) and midly-virulent non-defoliating (ND) isolates. Inhibition of Verticillium growth in
media where strain CECT 2413 had previously grown showed that this ability might be dueto the excretion of secondary metabolites or cell wall degrading enzymes. Furthermore, monitoring of in vitro direct confrontaban assays between an eyfp-labelled derivative of V. dahliae and a gfp-labelled transformant of CECT 2413 by confocal laser scanning microscopy (CLSM) revealed that mycoparasitism is one ofthe mechanisms involved in this antagonism. Indeed, typical coiling structures of T. harzianum around V. dahliae hyphae were clearly observe d. When a suspension of conidia of T. harzianum CECT 2413 were applied by irrigation to roots ofnursery-propagated, three-month-old olives (cv. Picual) prior to the treatmentwith a D isolate ofthe pathogen, disease symptoms were significantly reduced compared to that observed in control plants. Moreover, increase in the number and size ofleaves in plants treated with Trichoderma was also reported. Finally, colonization of olive roots surface by T. harzianum CECT 2413 during a prolonged period oftime was demonstrated by CLSM. In summary, T. harzianum CECT 2413 is an efficient colonizer of olive roots andan effective BCA against the D pathotype of V. dahliae
12th European Conference on Fungal Genetics (2014)
http://hdl.handle.net/10261/160098
http://dx.doi.org/10.13039/501100000780
http://dx.doi.org/10.13039/501100011011
Biological Control of Verticillium wilt of olive by Trichoderma harzianum