[en] An interaction study was performed with mycorrhizal plants of the grapevine rootstock Richter 110 (Vitis berlandieri Planch &times; Vitis rupestris Scheele) and the root pathogenic fungus Armillaria mellea (Vahl:Fr.) P. Kumm using an autotrophic in vitro culture system. Micropropagated plantlets were transferred to Petri plates with MSR medium lacking sugar and vitamins. Inocula of Glomus intraradices (BEG 72) and of Armillaria mellea obtained from a root organ culture and from a mycelium colony grown in malt agar respectively, were added to the plates according to each treatment: non-inoculated, inoculated with G. intraradices, inoculated with A. mellea, and dual-inoculated plants. There were ten replicates per treatment. Fourteen weeks later, the pathogen's mycelium occupied most of the surface/volume of the plate and had produced rhizomorphs. In dual inoculated plates, A. mellea's growth was not affected by the presence of G. intraradices, but the latter produced a lower number of spores and its extraradical phase showed granulation, vacuolation and tip swelling. The pathogen induced necrosis and growth decrease in the root. Glomus intraradices alleviated these symptoms and there were no differences in root biomass between non-inoculated plants and plants inoculated with both fungi. There were no symptoms of the disease in shoots and G. intraradices stimulated shoot growth both, although mycorrhizal colonization was lower when A. mellea was present. No direct antagonism or antibiosis against the pathogen was observed, thus the protective effect exerted by the symbiotic fungus in grapevines must be indirect, mediated through the host plant physiology.

[es] Se estudi&oacute; la interacci&oacute;n entre plantas micorrizadas del portainjerto de vid 110 Richter (Vitis berlandieri Planch &times; Vitis rupestris Scheele) y Armillaria mellea (Vahl:Fr.) P. Kumm en cultivo autotr&oacute;fico in vitro. Plantas micropropagadas fueron transferidas a placas de Petri con medio MSR sin az&uacute;car ni vitaminas. In&oacute;culo de Glomus intraradices Schenck and Smith (BEG 72) obtenido a partir de un cultivo ax&eacute;nico de ra&iacute;ces transformadas micorrizadas, e in&oacute;culo de A. mellea obtenido en medio agar-malta, se a&ntilde;adieron a las placas seg&uacute;n tratamiento: no inoculado, inoculaci&oacute;n con G. intraradices, inoculaci&oacute;n con A. mellea e inoculaci&oacute;n combinada, estableci&eacute;ndose 10 r&eacute;plicas por tratamiento. Catorce semanas despu&eacute;s, el micelio del hongo pat&oacute;geno ocupaba casi la totalidad de la superficie/volumen de la placa y hab&iacute;a producido rizomorfos. En placas con inoculaci&oacute;n mixta, el desarrollo de A. mellea no se vio afectado por la presencia de G. intraradices, mientras que &eacute;ste produjo menos esporas, y su fase extraradical presentaba granulaciones, vacuolaciones y engrosamientos en las terminaciones. El pat&oacute;geno indujo necrosis y menor desarrollo radical. Glomus intraradices alivi&oacute; estos s&iacute;ntomas, y no se observaron diferencias entre la biomasa radical de plantas no inoculadas y de plantas inoculadas con ambos hongos. No aparecieron s&iacute;ntomas de la enfermedad en la parte a&eacute;rea y G. intraradices estimul&oacute; en cualquier caso el crecimiento, pero la colonizaci&oacute;n micorr&iacute;cica fue menor en presencia del pat&oacute;geno. No se observ&oacute; antagonismo directo o antibiosis, el efecto de protecci&oacute;n de la simbiosis micorr&iacute;cica en vid frente a A. mellea debe ser indirecto, a trav&eacute;s de la fisiolog&iacute;a del hospedador.